[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
irst new item and emits only:
 *
 *   previous EOS, tool results, and the next assistant prefix.
 *
 * This is intentionally independent from req.prompt's already-tokenized suffix:
 * suffix tokenization happens later after the cache decision, using the live
 * token prefix as the boundary.  That avoids BPE merges across the visible
 * replay/live-KV boundary. */
static char *render_live_tool_tail(const chat_msgs *msgs, int start,
                                   ds4_think_mode think_mode) {
    const bool think = ds4_think_mode_enabled(think_mode);
    buf out = {0};
    buf_puts(&out, "<｜end▁of▁sentence｜>");

    bool pending_assistant = false;
    bool pending_tool_result = false;
    for (int i = start; msgs && i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (role_is_system(m->role)) {
            continue;
        } else if (!strcmp(m->role, "user")) {
            buf_puts(&out, "<｜User｜>");
            buf_puts(&out, m->content ? m->content : "");
            pending_assistant = true;
            pending_tool_result = false;
        } else if (!strcmp(m->role, "tool") || !strcmp(m->role, "function")) {
            if (!pending_tool_result) buf_puts(&out, "<｜User｜>");
            buf_puts(&out, "<tool_result>");
            append_tool_result_text(&out, m->content);
            buf_puts(&out, "</tool_result>");
            pending_assistant = true;
            pending_tool_result = true;
        } else if (!strcmp(m->role, "assistant")) {
            if (pending_assistant) {
                buf_puts(&out, "<｜Assistant｜>");
                if (think) {
                    buf_puts(&out, "<think>");
                    buf_puts(&out, m->reasoning ? m->reasoning : "");
                    buf_puts(&out, "</think>");
                } else {
                    buf_puts(&out, "</think>");
                }
            }
            buf_puts(&out, m->content ? m->content : "");
            append_dsml_tool_calls_text(&out, &m->calls);
            buf_puts(&out, "<｜end▁of▁sentence｜>");
            pending_assistant = false;
            pending_tool_result = false;
        }
    }

    if (pending_assistant) {
        buf_puts(&out, "<｜Assistant｜>");
        buf_puts(&out, think ? "<think>" : "</think>");
    }
    return buf_take(&out);
}

static bool chat_msg_has_call_id(const chat_msg *m, const char *id) {
    if (!m || !id || !id[0] || strcmp(m->role, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
irst new item and emits only:
 *
 *   previous EOS, tool results, and the next assistant prefix.
 *
 * This is intentionally independent from req.prompt's already-tokenized suffix:
 * suffix tokenization happens later after the cache decision, using the live
 * token prefix as the boundary.  That avoids BPE merges across the visible
 * replay/live-KV boundary. */
static char *render_live_tool_tail(const chat_msgs *msgs, int start,
                                   ds4_think_mode think_mode) {
    const bool think = ds4_think_mode_enabled(think_mode);
    buf out = {0};
    buf_puts(&out, "<｜end▁of▁sentence｜>");

    bool pending_assistant = false;
    bool pending_tool_result = false;
    for (int i = start; msgs && i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (role_is_system(m->role)) {
            continue;
        } else if (!strcmp(m->role, "user")) {
            buf_puts(&out, "<｜User｜>");
            buf_puts(&out, m->content ? m->content : "");
            pending_assistant = true;
            pending_tool_result = false;
        } else if (!strcmp(m->role, "tool") || !strcmp(m->role, "function")) {
            if (!pending_tool_result) buf_puts(&out, "<｜User｜>");
            buf_puts(&out, "<tool_result>");
            append_tool_result_text(&out, m->content);
            buf_puts(&out, "</tool_result>");
            pending_assistant = true;
            pending_tool_result = true;
        } else if (!strcmp(m->role, "assistant")) {
            if (pending_assistant) {
                buf_puts(&out, "<｜Assistant｜>");
                if (think) {
                    buf_puts(&out, "<think>");
                    buf_puts(&out, m->reasoning ? m->reasoning : "");
                    buf_puts(&out, "</think>");
                } else {
                    buf_puts(&out, "</think>");
                }
            }
            buf_puts(&out, m->content ? m->content : "");
            append_dsml_tool_calls_text(&out, &m->calls);
            buf_puts(&out, "<｜end▁of▁sentence｜>");
            pending_assistant = false;
            pending_tool_result = false;
        }
    }

    if (pending_assistant) {
        buf_puts(&out, "<｜Assistant｜>");
        buf_puts(&out, think ? "<think>" : "</think>");
    }
    return buf_take(&out);
}

static bool chat_msg_has_call_id(const chat_msg *m, const char *id) {
    if (!m || !id || !id[0] || strcmp(m->role, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
ds we use and skips the
 * rest.  Skipping is recursive because JSON values nest, so keep an explicit
 * ceiling: without it, a useless ignored field like {"x":[[[...]]]} can spend
 * the whole C stack before the request is rejected. */
#define JSON_MAX_NESTING 256

static bool json_skip_value_depth(const char **p, int depth);

static bool json_skip_array_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '[') return false;
    (*p)++;
    json_ws(p);
    if (**p == ']') {
        (*p)++;
        return true;
    }
    for (;;) {
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == ']') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_object_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '{') return false;
    (*p)++;
    json_ws(p);
    if (**p == '}') {
        (*p)++;
        return true;
    }
    for (;;) {
        char *key = NULL;
        if (!json_string(p, &key)) return false;
        free(key);
        json_ws(p);
        if (**p != ':') return false;
        (*p)++;
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == '}') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_value_depth(const char **p, int depth) {
    json_ws(p);
    if (**p == '"') {
        char *s = NULL;
        bool ok = json_string(p, &s);
        free(s);
        return ok;
    }
    if (**p == '{') return json_skip_object_depth(p, depth);
    if (**p == '[') return json_skip_array_depth(p, depth);
    if (json_lit(p, "true") || json_lit(p, "false") || json_lit(p, "null")) return true;
    double v = 0.0;
    return json_number(p, &v);
}

static bool json_skip_value(const char **p) {
    return json_skip_value_depth(p, 0);
}

static bool json_raw_value(const char **p, char **out) {
    json_ws(p);
    const char *start = *p;
    if (!json_skip_value(p)) return false;
    size_t n = (size_t)(*p - start);
    char *s = xmalloc(n + 1);
    memcpy(s, start, n);
    s[n] = '\0';
    *out = s;
    return true;
}

static char *json_minify_raw_value(const char *json) {
    const char *p = json ? json : "null";
    json_ws(&p);
    const char *start = p;
    if (!json_skip_value(&p)) return xstrdup(json ? json : "null");
    const char *end = p;

    buf b = {0};
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
ds we use and skips the
 * rest.  Skipping is recursive because JSON values nest, so keep an explicit
 * ceiling: without it, a useless ignored field like {"x":[[[...]]]} can spend
 * the whole C stack before the request is rejected. */
#define JSON_MAX_NESTING 256

static bool json_skip_value_depth(const char **p, int depth);

static bool json_skip_array_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '[') return false;
    (*p)++;
    json_ws(p);
    if (**p == ']') {
        (*p)++;
        return true;
    }
    for (;;) {
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == ']') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_object_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '{') return false;
    (*p)++;
    json_ws(p);
    if (**p == '}') {
        (*p)++;
        return true;
    }
    for (;;) {
        char *key = NULL;
        if (!json_string(p, &key)) return false;
        free(key);
        json_ws(p);
        if (**p != ':') return false;
        (*p)++;
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == '}') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_value_depth(const char **p, int depth) {
    json_ws(p);
    if (**p == '"') {
        char *s = NULL;
        bool ok = json_string(p, &s);
        free(s);
        return ok;
    }
    if (**p == '{') return json_skip_object_depth(p, depth);
    if (**p == '[') return json_skip_array_depth(p, depth);
    if (json_lit(p, "true") || json_lit(p, "false") || json_lit(p, "null")) return true;
    double v = 0.0;
    return json_number(p, &v);
}

static bool json_skip_value(const char **p) {
    return json_skip_value_depth(p, 0);
}

static bool json_raw_value(const char **p, char **out) {
    json_ws(p);
    const char *start = *p;
    if (!json_skip_value(p)) return false;
    size_t n = (size_t)(*p - start);
    char *s = xmalloc(n + 1);
    memcpy(s, start, n);
    s[n] = '\0';
    *out = s;
    return true;
}

static char *json_minify_raw_value(const char *json) {
    const char *p = json ? json : "null";
    json_ws(&p);
    const char *start = p;
    if (!json_skip_value(&p)) return xstrdup(json ? json : "null");
    const char *end = p;

    buf b = {0};
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
ds we use and skips the
 * rest.  Skipping is recursive because JSON values nest, so keep an explicit
 * ceiling: without it, a useless ignored field like {"x":[[[...]]]} can spend
 * the whole C stack before the request is rejected. */
#define JSON_MAX_NESTING 256

static bool json_skip_value_depth(const char **p, int depth);

static bool json_skip_array_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '[') return false;
    (*p)++;
    json_ws(p);
    if (**p == ']') {
        (*p)++;
        return true;
    }
    for (;;) {
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == ']') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_object_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '{') return false;
    (*p)++;
    json_ws(p);
    if (**p == '}') {
        (*p)++;
        return true;
    }
    for (;;) {
        char *key = NULL;
        if (!json_string(p, &key)) return false;
        free(key);
        json_ws(p);
        if (**p != ':') return false;
        (*p)++;
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == '}') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_value_depth(const char **p, int depth) {
    json_ws(p);
    if (**p == '"') {
        char *s = NULL;
        bool ok = json_string(p, &s);
        free(s);
        return ok;
    }
    if (**p == '{') return json_skip_object_depth(p, depth);
    if (**p == '[') return json_skip_array_depth(p, depth);
    if (json_lit(p, "true") || json_lit(p, "false") || json_lit(p, "null")) return true;
    double v = 0.0;
    return json_number(p, &v);
}

static bool json_skip_value(const char **p) {
    return json_skip_value_depth(p, 0);
}

static bool json_raw_value(const char **p, char **out) {
    json_ws(p);
    const char *start = *p;
    if (!json_skip_value(p)) return false;
    size_t n = (size_t)(*p - start);
    char *s = xmalloc(n + 1);
    memcpy(s, start, n);
    s[n] = '\0';
    *out = s;
    return true;
}

static char *json_minify_raw_value(const char *json) {
    const char *p = json ? json : "null";
    json_ws(&p);
    const char *start = p;
    if (!json_skip_value(&p)) return xstrdup(json ? json : "null");
    const char *end = p;

    buf b = {0};
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
ds we use and skips the
 * rest.  Skipping is recursive because JSON values nest, so keep an explicit
 * ceiling: without it, a useless ignored field like {"x":[[[...]]]} can spend
 * the whole C stack before the request is rejected. */
#define JSON_MAX_NESTING 256

static bool json_skip_value_depth(const char **p, int depth);

static bool json_skip_array_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '[') return false;
    (*p)++;
    json_ws(p);
    if (**p == ']') {
        (*p)++;
        return true;
    }
    for (;;) {
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == ']') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_object_depth(const char **p, int depth) {
    if (depth >= JSON_MAX_NESTING) return false;
    json_ws(p);
    if (**p != '{') return false;
    (*p)++;
    json_ws(p);
    if (**p == '}') {
        (*p)++;
        return true;
    }
    for (;;) {
        char *key = NULL;
        if (!json_string(p, &key)) return false;
        free(key);
        json_ws(p);
        if (**p != ':') return false;
        (*p)++;
        if (!json_skip_value_depth(p, depth + 1)) return false;
        json_ws(p);
        if (**p == '}') {
            (*p)++;
            return true;
        }
        if (**p != ',') return false;
        (*p)++;
    }
}

static bool json_skip_value_depth(const char **p, int depth) {
    json_ws(p);
    if (**p == '"') {
        char *s = NULL;
        bool ok = json_string(p, &s);
        free(s);
        return ok;
    }
    if (**p == '{') return json_skip_object_depth(p, depth);
    if (**p == '[') return json_skip_array_depth(p, depth);
    if (json_lit(p, "true") || json_lit(p, "false") || json_lit(p, "null")) return true;
    double v = 0.0;
    return json_number(p, &v);
}

static bool json_skip_value(const char **p) {
    return json_skip_value_depth(p, 0);
}

static bool json_raw_value(const char **p, char **out) {
    json_ws(p);
    const char *start = *p;
    if (!json_skip_value(p)) return false;
    size_t n = (size_t)(*p - start);
    char *s = xmalloc(n + 1);
    memcpy(s, start, n);
    s[n] = '\0';
    *out = s;
    return true;
}

static char *json_minify_raw_value(const char *json) {
    const char *p = json ? json : "null";
    json_ws(&p);
    const char *start = p;
    if (!json_skip_value(&p)) return xstrdup(json ? json : "null");
    const char *end = p;

    buf b = {0};
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
ole, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}

static void chat_msg_collect_tool_call_ids(const chat_msg *m, stop_list *ids) {
    if (!m || !ids) return;
    id_list_push_unique(ids, m->tool_call_id);
    for (int i = 0; i < m->tool_call_ids_len; i++) {
        id_list_push_unique(ids, m->tool_call_ids[i]);
    }
}

static const chat_msg *responses_find_prior_call_msg(const chat_msgs *msgs,
                                                     int before,
                                                     const char *id) {
    if (!msgs || !id || !id[0]) return NULL;
    if (before > msgs->len) before = msgs->len;
    for (int i = before - 1; i >= 0; i--) {
        if (chat_msg_has_call_id(&msgs->v[i], id)) return &msgs->v[i];
    }
    return NULL;
}

/* Validate Responses tool outputs before rendering.
 *
 * A tool output with a call_id is meaningful only if either:
 *   1. DS4 still has the matching live assistant call in memory, or
 *   2. the same request replays the prior assistant call item.
 *
 * Case 1 is the fast, protocol-native continuation path: keep the live KV and
 * append only the tool result.  Case 2 is stateless replay after restart or
 * branching.  In thinking mode, case 2 is less faithful if the replay omits
 * reasoning state for the assistant call.  Official Responses clients can
 * carry that state with reasoning items / encrypted reasoning content; when
 * they do not, the request is still renderable as visible history.  Mark that
 * condition so generate_job() can prefer live / visible checkpoints and emit a
 * warning if it must fall back to visible replay instead of aborting the
 * session. */
static bool responses_validate_tool_outputs(server *s, const chat_msgs *msgs,
                                            ds4_think_mode think_mode,
                                            bool *requires_live_tool_state,
                                            bool *requires_live_reasoning,
                                            char *err, size_t errlen) {
    if (!msgs) return true;
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (requires_live_reasoning) *requires_live_reasoning = false;
    const bool needs_reasoning = ds4_think_mode_enabled(think_mode);
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
ole, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}

static void chat_msg_collect_tool_call_ids(const chat_msg *m, stop_list *ids) {
    if (!m || !ids) return;
    id_list_push_unique(ids, m->tool_call_id);
    for (int i = 0; i < m->tool_call_ids_len; i++) {
        id_list_push_unique(ids, m->tool_call_ids[i]);
    }
}

static const chat_msg *responses_find_prior_call_msg(const chat_msgs *msgs,
                                                     int before,
                                                     const char *id) {
    if (!msgs || !id || !id[0]) return NULL;
    if (before > msgs->len) before = msgs->len;
    for (int i = before - 1; i >= 0; i--) {
        if (chat_msg_has_call_id(&msgs->v[i], id)) return &msgs->v[i];
    }
    return NULL;
}

/* Validate Responses tool outputs before rendering.
 *
 * A tool output with a call_id is meaningful only if either:
 *   1. DS4 still has the matching live assistant call in memory, or
 *   2. the same request replays the prior assistant call item.
 *
 * Case 1 is the fast, protocol-native continuation path: keep the live KV and
 * append only the tool result.  Case 2 is stateless replay after restart or
 * branching.  In thinking mode, case 2 is less faithful if the replay omits
 * reasoning state for the assistant call.  Official Responses clients can
 * carry that state with reasoning items / encrypted reasoning content; when
 * they do not, the request is still renderable as visible history.  Mark that
 * condition so generate_job() can prefer live / visible checkpoints and emit a
 * warning if it must fall back to visible replay instead of aborting the
 * session. */
static bool responses_validate_tool_outputs(server *s, const chat_msgs *msgs,
                                            ds4_think_mode think_mode,
                                            bool *requires_live_tool_state,
                                            bool *requires_live_reasoning,
                                            char *err, size_t errlen) {
    if (!msgs) return true;
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (requires_live_reasoning) *requires_live_reasoning = false;
    const bool needs_reasoning = ds4_think_mode_enabled(think_mode);
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
ole, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}

static void chat_msg_collect_tool_call_ids(const chat_msg *m, stop_list *ids) {
    if (!m || !ids) return;
    id_list_push_unique(ids, m->tool_call_id);
    for (int i = 0; i < m->tool_call_ids_len; i++) {
        id_list_push_unique(ids, m->tool_call_ids[i]);
    }
}

static const chat_msg *responses_find_prior_call_msg(const chat_msgs *msgs,
                                                     int before,
                                                     const char *id) {
    if (!msgs || !id || !id[0]) return NULL;
    if (before > msgs->len) before = msgs->len;
    for (int i = before - 1; i >= 0; i--) {
        if (chat_msg_has_call_id(&msgs->v[i], id)) return &msgs->v[i];
    }
    return NULL;
}

/* Validate Responses tool outputs before rendering.
 *
 * A tool output with a call_id is meaningful only if either:
 *   1. DS4 still has the matching live assistant call in memory, or
 *   2. the same request replays the prior assistant call item.
 *
 * Case 1 is the fast, protocol-native continuation path: keep the live KV and
 * append only the tool result.  Case 2 is stateless replay after restart or
 * branching.  In thinking mode, case 2 is less faithful if the replay omits
 * reasoning state for the assistant call.  Official Responses clients can
 * carry that state with reasoning items / encrypted reasoning content; when
 * they do not, the request is still renderable as visible history.  Mark that
 * condition so generate_job() can prefer live / visible checkpoints and emit a
 * warning if it must fall back to visible replay instead of aborting the
 * session. */
static bool responses_validate_tool_outputs(server *s, const chat_msgs *msgs,
                                            ds4_think_mode think_mode,
                                            bool *requires_live_tool_state,
                                            bool *requires_live_reasoning,
                                            char *err, size_t errlen) {
    if (!msgs) return true;
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (requires_live_reasoning) *requires_live_reasoning = false;
    const bool needs_reasoning = ds4_think_mode_enabled(think_mode);
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
ole, "assistant")) return false;
    for (int i = 0; i < m->calls.len; i++) {
        if (m->calls.v[i].id && !strcmp(m->calls.v[i].id, id)) return true;
    }
    return false;
}

static void chat_msg_collect_tool_call_ids(const chat_msg *m, stop_list *ids) {
    if (!m || !ids) return;
    id_list_push_unique(ids, m->tool_call_id);
    for (int i = 0; i < m->tool_call_ids_len; i++) {
        id_list_push_unique(ids, m->tool_call_ids[i]);
    }
}

static const chat_msg *responses_find_prior_call_msg(const chat_msgs *msgs,
                                                     int before,
                                                     const char *id) {
    if (!msgs || !id || !id[0]) return NULL;
    if (before > msgs->len) before = msgs->len;
    for (int i = before - 1; i >= 0; i--) {
        if (chat_msg_has_call_id(&msgs->v[i], id)) return &msgs->v[i];
    }
    return NULL;
}

/* Validate Responses tool outputs before rendering.
 *
 * A tool output with a call_id is meaningful only if either:
 *   1. DS4 still has the matching live assistant call in memory, or
 *   2. the same request replays the prior assistant call item.
 *
 * Case 1 is the fast, protocol-native continuation path: keep the live KV and
 * append only the tool result.  Case 2 is stateless replay after restart or
 * branching.  In thinking mode, case 2 is less faithful if the replay omits
 * reasoning state for the assistant call.  Official Responses clients can
 * carry that state with reasoning items / encrypted reasoning content; when
 * they do not, the request is still renderable as visible history.  Mark that
 * condition so generate_job() can prefer live / visible checkpoints and emit a
 * warning if it must fall back to visible replay instead of aborting the
 * session. */
static bool responses_validate_tool_outputs(server *s, const chat_msgs *msgs,
                                            ds4_think_mode think_mode,
                                            bool *requires_live_tool_state,
                                            bool *requires_live_reasoning,
                                            char *err, size_t errlen) {
    if (!msgs) return true;
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (requires_live_reasoning) *requires_live_reasoning = false;
    const bool needs_reasoning = ds4_think_mode_enabled(think_mode);
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
nt i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = responses_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Responses continuation state is not available for call_id %s; retry by replaying the full input history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior) {
                if (requires_live_tool_state) *requires_live_tool_state = true;
                continue;
            }
            if (needs_reasoning &&
                (!prior->reasoning || !prior->reasoning[0]))
            {
                if (requires_live_reasoning) *requires_live_reasoning = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Record the call ids and suffix candidate for a live Responses continuation.
 *
 * This only prepares evidence.  generate_job() later checks that the live
 * server state is still exactly at the remembered token frontier before using
 * it.  If another request already replaced the session, normal token/text/disk
 * prefix matching handles the request instead. */
static void responses_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_RESPONSES || !msgs || msgs->len == 0) return;

    int tail_start = msgs->len;
    while (tail_start > 0) {
        const chat_msg *m = &msgs->v[tail_start - 1];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) break;
        tail_start--;
    }
    if (tail_start == msgs->len) return;

    stop_list_clear(&r->responses_live_call_ids);
    if (tail_start > 0) {
        const int anchor = tail_start - 1;
        const chat_msg *assistant = &msgs->v[anchor];
        if (strcmp(assistant->role, "assistant") || assistant->calls.len == 0) return;
        for (int i = 0; i < assistant->calls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
nt i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = responses_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Responses continuation state is not available for call_id %s; retry by replaying the full input history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior) {
                if (requires_live_tool_state) *requires_live_tool_state = true;
                continue;
            }
            if (needs_reasoning &&
                (!prior->reasoning || !prior->reasoning[0]))
            {
                if (requires_live_reasoning) *requires_live_reasoning = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Record the call ids and suffix candidate for a live Responses continuation.
 *
 * This only prepares evidence.  generate_job() later checks that the live
 * server state is still exactly at the remembered token frontier before using
 * it.  If another request already replaced the session, normal token/text/disk
 * prefix matching handles the request instead. */
static void responses_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_RESPONSES || !msgs || msgs->len == 0) return;

    int tail_start = msgs->len;
    while (tail_start > 0) {
        const chat_msg *m = &msgs->v[tail_start - 1];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) break;
        tail_start--;
    }
    if (tail_start == msgs->len) return;

    stop_list_clear(&r->responses_live_call_ids);
    if (tail_start > 0) {
        const int anchor = tail_start - 1;
        const chat_msg *assistant = &msgs->v[anchor];
        if (strcmp(assistant->role, "assistant") || assistant->calls.len == 0) return;
        for (int i = 0; i < assistant->calls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
nt i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = responses_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Responses continuation state is not available for call_id %s; retry by replaying the full input history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior) {
                if (requires_live_tool_state) *requires_live_tool_state = true;
                continue;
            }
            if (needs_reasoning &&
                (!prior->reasoning || !prior->reasoning[0]))
            {
                if (requires_live_reasoning) *requires_live_reasoning = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Record the call ids and suffix candidate for a live Responses continuation.
 *
 * This only prepares evidence.  generate_job() later checks that the live
 * server state is still exactly at the remembered token frontier before using
 * it.  If another request already replaced the session, normal token/text/disk
 * prefix matching handles the request instead. */
static void responses_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_RESPONSES || !msgs || msgs->len == 0) return;

    int tail_start = msgs->len;
    while (tail_start > 0) {
        const chat_msg *m = &msgs->v[tail_start - 1];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) break;
        tail_start--;
    }
    if (tail_start == msgs->len) return;

    stop_list_clear(&r->responses_live_call_ids);
    if (tail_start > 0) {
        const int anchor = tail_start - 1;
        const chat_msg *assistant = &msgs->v[anchor];
        if (strcmp(assistant->role, "assistant") || assistant->calls.len == 0) return;
        for (int i = 0; i < assistant->calls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
nt i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = responses_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Responses continuation state is not available for call_id %s; retry by replaying the full input history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior) {
                if (requires_live_tool_state) *requires_live_tool_state = true;
                continue;
            }
            if (needs_reasoning &&
                (!prior->reasoning || !prior->reasoning[0]))
            {
                if (requires_live_reasoning) *requires_live_reasoning = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Record the call ids and suffix candidate for a live Responses continuation.
 *
 * This only prepares evidence.  generate_job() later checks that the live
 * server state is still exactly at the remembered token frontier before using
 * it.  If another request already replaced the session, normal token/text/disk
 * prefix matching handles the request instead. */
static void responses_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_RESPONSES || !msgs || msgs->len == 0) return;

    int tail_start = msgs->len;
    while (tail_start > 0) {
        const chat_msg *m = &msgs->v[tail_start - 1];
        if (strcmp(m->role, "tool") && strcmp(m->role, "function")) break;
        tail_start--;
    }
    if (tail_start == msgs->len) return;

    stop_list_clear(&r->responses_live_call_ids);
    if (tail_start > 0) {
        const int anchor = tail_start - 1;
        const chat_msg *assistant = &msgs->v[anchor];
        if (strcmp(assistant->role, "assistant") || assistant->calls.len == 0) return;
        for (int i = 0; i < assistant->calls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
ls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
            chat_msg_collect_tool_call_ids(&msgs->v[i], &r->responses_live_call_ids);
        }
    }
    if (r->responses_live_call_ids.len == 0) return;

    free(r->responses_live_suffix_text);
    r->responses_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

static bool anthropic_msg_is_tool_result_tail(const chat_msg *m) {
    return m && !strcmp(m->role, "user") &&
           ((m->tool_call_id && m->tool_call_id[0]) ||
            m->tool_call_ids_len > 0);
}

/* Validate Anthropic tool results before rendering.
 *
 * A tool_result.tool_use_id is valid if it is either still bound to the live
 * Anthropic assistant tool-call frontier or the same request replays the prior
 * assistant tool_use block.  The first case is the fast path: keep the sampled
 * KV and append only the tool-result suffix.  The second case is a normal
 * stateless replay, where exact DSML tool memory can restore the sampled tool
 * bytes before prefix matching.  A tool-result-only request with an unknown
 * live id has no safe prefix to reconstruct, so report a clear client error. */
static bool anthropic_validate_tool_results(server *s, const chat_msgs *msgs,
                                            bool *requires_live_tool_state,
                                            char *err, size_t errlen) {
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (!msgs) return true;
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (!anthropic_msg_is_tool_result_tail(m)) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = anthropic_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Anthropic continuation state is not available for tool_use_id %s; retry by replaying the full messages history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
ls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
            chat_msg_collect_tool_call_ids(&msgs->v[i], &r->responses_live_call_ids);
        }
    }
    if (r->responses_live_call_ids.len == 0) return;

    free(r->responses_live_suffix_text);
    r->responses_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

static bool anthropic_msg_is_tool_result_tail(const chat_msg *m) {
    return m && !strcmp(m->role, "user") &&
           ((m->tool_call_id && m->tool_call_id[0]) ||
            m->tool_call_ids_len > 0);
}

/* Validate Anthropic tool results before rendering.
 *
 * A tool_result.tool_use_id is valid if it is either still bound to the live
 * Anthropic assistant tool-call frontier or the same request replays the prior
 * assistant tool_use block.  The first case is the fast path: keep the sampled
 * KV and append only the tool-result suffix.  The second case is a normal
 * stateless replay, where exact DSML tool memory can restore the sampled tool
 * bytes before prefix matching.  A tool-result-only request with an unknown
 * live id has no safe prefix to reconstruct, so report a clear client error. */
static bool anthropic_validate_tool_results(server *s, const chat_msgs *msgs,
                                            bool *requires_live_tool_state,
                                            char *err, size_t errlen) {
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (!msgs) return true;
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (!anthropic_msg_is_tool_result_tail(m)) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = anthropic_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Anthropic continuation state is not available for tool_use_id %s; retry by replaying the full messages history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
ls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
            chat_msg_collect_tool_call_ids(&msgs->v[i], &r->responses_live_call_ids);
        }
    }
    if (r->responses_live_call_ids.len == 0) return;

    free(r->responses_live_suffix_text);
    r->responses_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

static bool anthropic_msg_is_tool_result_tail(const chat_msg *m) {
    return m && !strcmp(m->role, "user") &&
           ((m->tool_call_id && m->tool_call_id[0]) ||
            m->tool_call_ids_len > 0);
}

/* Validate Anthropic tool results before rendering.
 *
 * A tool_result.tool_use_id is valid if it is either still bound to the live
 * Anthropic assistant tool-call frontier or the same request replays the prior
 * assistant tool_use block.  The first case is the fast path: keep the sampled
 * KV and append only the tool-result suffix.  The second case is a normal
 * stateless replay, where exact DSML tool memory can restore the sampled tool
 * bytes before prefix matching.  A tool-result-only request with an unknown
 * live id has no safe prefix to reconstruct, so report a clear client error. */
static bool anthropic_validate_tool_results(server *s, const chat_msgs *msgs,
                                            bool *requires_live_tool_state,
                                            char *err, size_t errlen) {
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (!msgs) return true;
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (!anthropic_msg_is_tool_result_tail(m)) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = anthropic_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Anthropic continuation state is not available for tool_use_id %s; retry by replaying the full messages history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
ls.len; i++) {
            id_list_push_unique(&r->responses_live_call_ids, assistant->calls.v[i].id);
        }
    } else {
        for (int i = tail_start; i < msgs->len; i++) {
            chat_msg_collect_tool_call_ids(&msgs->v[i], &r->responses_live_call_ids);
        }
    }
    if (r->responses_live_call_ids.len == 0) return;

    free(r->responses_live_suffix_text);
    r->responses_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

static bool anthropic_msg_is_tool_result_tail(const chat_msg *m) {
    return m && !strcmp(m->role, "user") &&
           ((m->tool_call_id && m->tool_call_id[0]) ||
            m->tool_call_ids_len > 0);
}

/* Validate Anthropic tool results before rendering.
 *
 * A tool_result.tool_use_id is valid if it is either still bound to the live
 * Anthropic assistant tool-call frontier or the same request replays the prior
 * assistant tool_use block.  The first case is the fast path: keep the sampled
 * KV and append only the tool-result suffix.  The second case is a normal
 * stateless replay, where exact DSML tool memory can restore the sampled tool
 * bytes before prefix matching.  A tool-result-only request with an unknown
 * live id has no safe prefix to reconstruct, so report a clear client error. */
static bool anthropic_validate_tool_results(server *s, const chat_msgs *msgs,
                                            bool *requires_live_tool_state,
                                            char *err, size_t errlen) {
    if (requires_live_tool_state) *requires_live_tool_state = false;
    if (!msgs) return true;
    for (int i = 0; i < msgs->len; i++) {
        const chat_msg *m = &msgs->v[i];
        if (!anthropic_msg_is_tool_result_tail(m)) continue;

        stop_list ids = {0};
        chat_msg_collect_tool_call_ids(m, &ids);
        for (int j = 0; j < ids.len; j++) {
            const char *id = ids.v[j];
            const bool live_known = anthropic_live_has_call_id(s, id);
            const chat_msg *prior = responses_find_prior_call_msg(msgs, i, id);
            if (!live_known && !prior) {
                snprintf(err, errlen,
                         "Anthropic continuation state is not available for tool_use_id %s; retry by replaying the full messages history",
                         id);
                id_list_free(&ids);
                return false;
            }
            if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Prepare the Anthropic live-tool fast path.
 *
 * Anthropic's visible replay normally includes the assistant tool_use JSON and
 * the user tool_result.  That replay is still only a description of what the
 * model sampled.  If the incoming tool_result IDs match the live sampled
 * frontier, generate_job() can skip replay matching entirely and append just
 * EOS + tool_result + next assistant prefix to the real KV. */
static void anthropic_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_ANTHROPIC || !msgs || msgs->len == 0) return;

    int tail_end = msgs->len;
    while (tail_end > 0 && role_is_system(msgs->v[tail_end - 1].role)) tail_end--;
    int tail_start = tail_end;
    while (tail_start > 0 &&
           anthropic_msg_is_tool_result_tail(&msgs->v[tail_start - 1]))
    {
        tail_start--;
    }
    if (tail_start == tail_end) return;

    stop_list_clear(&r->anthropic_live_call_ids);
    for (int i = tail_start; i < msgs->len; i++) {
        chat_msg_collect_tool_call_ids(&msgs->v[i], &r->anthropic_live_call_ids);
    }
    if (r->anthropic_live_call_ids.len == 0) return;

    free(r->anthropic_live_suffix_text);
    r->anthropic_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

/* The API parsers are intentionally selective JSON parsers: they keep only
 * fields that affect model semantics, rendering, streaming, or cache keys, and
 * skip extension fields.  The output is always a rendered DS4 chat/completion
 * prompt plus the small amount of protocol state needed to translate the reply. */
static bool parse_chat_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                               int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Prepare the Anthropic live-tool fast path.
 *
 * Anthropic's visible replay normally includes the assistant tool_use JSON and
 * the user tool_result.  That replay is still only a description of what the
 * model sampled.  If the incoming tool_result IDs match the live sampled
 * frontier, generate_job() can skip replay matching entirely and append just
 * EOS + tool_result + next assistant prefix to the real KV. */
static void anthropic_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_ANTHROPIC || !msgs || msgs->len == 0) return;

    int tail_end = msgs->len;
    while (tail_end > 0 && role_is_system(msgs->v[tail_end - 1].role)) tail_end--;
    int tail_start = tail_end;
    while (tail_start > 0 &&
           anthropic_msg_is_tool_result_tail(&msgs->v[tail_start - 1]))
    {
        tail_start--;
    }
    if (tail_start == tail_end) return;

    stop_list_clear(&r->anthropic_live_call_ids);
    for (int i = tail_start; i < msgs->len; i++) {
        chat_msg_collect_tool_call_ids(&msgs->v[i], &r->anthropic_live_call_ids);
    }
    if (r->anthropic_live_call_ids.len == 0) return;

    free(r->anthropic_live_suffix_text);
    r->anthropic_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

/* The API parsers are intentionally selective JSON parsers: they keep only
 * fields that affect model semantics, rendering, streaming, or cache keys, and
 * skip extension fields.  The output is always a rendered DS4 chat/completion
 * prompt plus the small amount of protocol state needed to translate the reply. */
static bool parse_chat_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                               int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Prepare the Anthropic live-tool fast path.
 *
 * Anthropic's visible replay normally includes the assistant tool_use JSON and
 * the user tool_result.  That replay is still only a description of what the
 * model sampled.  If the incoming tool_result IDs match the live sampled
 * frontier, generate_job() can skip replay matching entirely and append just
 * EOS + tool_result + next assistant prefix to the real KV. */
static void anthropic_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_ANTHROPIC || !msgs || msgs->len == 0) return;

    int tail_end = msgs->len;
    while (tail_end > 0 && role_is_system(msgs->v[tail_end - 1].role)) tail_end--;
    int tail_start = tail_end;
    while (tail_start > 0 &&
           anthropic_msg_is_tool_result_tail(&msgs->v[tail_start - 1]))
    {
        tail_start--;
    }
    if (tail_start == tail_end) return;

    stop_list_clear(&r->anthropic_live_call_ids);
    for (int i = tail_start; i < msgs->len; i++) {
        chat_msg_collect_tool_call_ids(&msgs->v[i], &r->anthropic_live_call_ids);
    }
    if (r->anthropic_live_call_ids.len == 0) return;

    free(r->anthropic_live_suffix_text);
    r->anthropic_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

/* The API parsers are intentionally selective JSON parsers: they keep only
 * fields that affect model semantics, rendering, streaming, or cache keys, and
 * skip extension fields.  The output is always a rendered DS4 chat/completion
 * prompt plus the small amount of protocol state needed to translate the reply. */
static bool parse_chat_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                               int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Explain what this code does and identify the inference stage it belongs to.

File: ds4_server.c

```c
if (!prior && requires_live_tool_state) {
                *requires_live_tool_state = true;
            }
        }
        id_list_free(&ids);
    }
    return true;
}

/* Prepare the Anthropic live-tool fast path.
 *
 * Anthropic's visible replay normally includes the assistant tool_use JSON and
 * the user tool_result.  That replay is still only a description of what the
 * model sampled.  If the incoming tool_result IDs match the live sampled
 * frontier, generate_job() can skip replay matching entirely and append just
 * EOS + tool_result + next assistant prefix to the real KV. */
static void anthropic_prepare_live_continuation(request *r,
                                                const chat_msgs *msgs) {
    if (!r || r->api != API_ANTHROPIC || !msgs || msgs->len == 0) return;

    int tail_end = msgs->len;
    while (tail_end > 0 && role_is_system(msgs->v[tail_end - 1].role)) tail_end--;
    int tail_start = tail_end;
    while (tail_start > 0 &&
           anthropic_msg_is_tool_result_tail(&msgs->v[tail_start - 1]))
    {
        tail_start--;
    }
    if (tail_start == tail_end) return;

    stop_list_clear(&r->anthropic_live_call_ids);
    for (int i = tail_start; i < msgs->len; i++) {
        chat_msg_collect_tool_call_ids(&msgs->v[i], &r->anthropic_live_call_ids);
    }
    if (r->anthropic_live_call_ids.len == 0) return;

    free(r->anthropic_live_suffix_text);
    r->anthropic_live_suffix_text =
        render_live_tool_tail(msgs, tail_start, r->think_mode);
}

/* The API parsers are intentionally selective JSON parsers: they keep only
 * fields that affect model semantics, rendering, streaming, or cache keys, and
 * skip extension fields.  The output is always a rendered DS4 chat/completion
 * prompt plus the small amount of protocol state needed to translate the reply. */
static bool parse_chat_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                               int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '"') {
                char *choice = NULL;
                if (!json_string(&p, &choice)) {
                    free(key);
                    goto bad;
                }
                tool_choice_none = !strcmp(choice, "none");
                free(choice);
            } else if (!json_skip_value(&p)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "model")) {
            free(r->model);
            if (!json_string(&p, &r->model)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "max_tokens") || !strcmp(key, "max_completion_tokens")) {
            if (!json_int(&p, &r->max_tokens)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "temperature")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->temperature = (float)v;
        } else if (!strcmp(key, "top_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->top_p = (float)v;
        } else if (!strcmp(key, "min_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->min_p = (float)v;
        } else if (!strcmp(key, "top_k")) {
            if (!json_int(&p, &r->top_k)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "seed")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '"') {
                char *choice = NULL;
                if (!json_string(&p, &choice)) {
                    free(key);
                    goto bad;
                }
                tool_choice_none = !strcmp(choice, "none");
                free(choice);
            } else if (!json_skip_value(&p)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "model")) {
            free(r->model);
            if (!json_string(&p, &r->model)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "max_tokens") || !strcmp(key, "max_completion_tokens")) {
            if (!json_int(&p, &r->max_tokens)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "temperature")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->temperature = (float)v;
        } else if (!strcmp(key, "top_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->top_p = (float)v;
        } else if (!strcmp(key, "min_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->min_p = (float)v;
        } else if (!strcmp(key, "top_k")) {
            if (!json_int(&p, &r->top_k)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "seed")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '"') {
                char *choice = NULL;
                if (!json_string(&p, &choice)) {
                    free(key);
                    goto bad;
                }
                tool_choice_none = !strcmp(choice, "none");
                free(choice);
            } else if (!json_skip_value(&p)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "model")) {
            free(r->model);
            if (!json_string(&p, &r->model)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "max_tokens") || !strcmp(key, "max_completion_tokens")) {
            if (!json_int(&p, &r->max_tokens)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "temperature")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->temperature = (float)v;
        } else if (!strcmp(key, "top_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->top_p = (float)v;
        } else if (!strcmp(key, "min_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->min_p = (float)v;
        } else if (!strcmp(key, "top_k")) {
            if (!json_int(&p, &r->top_k)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "seed")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Suggest a minimal correctness-preserving optimization for this excerpt.

File: ds4_server.c

```c
p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '"') {
                char *choice = NULL;
                if (!json_string(&p, &choice)) {
                    free(key);
                    goto bad;
                }
                tool_choice_none = !strcmp(choice, "none");
                free(choice);
            } else if (!json_skip_value(&p)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "model")) {
            free(r->model);
            if (!json_string(&p, &r->model)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "max_tokens") || !strcmp(key, "max_completion_tokens")) {
            if (!json_int(&p, &r->max_tokens)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "temperature")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->temperature = (float)v;
        } else if (!strcmp(key, "top_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->top_p = (float)v;
        } else if (!strcmp(key, "min_p")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->min_p = (float)v;
        } else if (!strcmp(key, "top_k")) {
            if (!json_int(&p, &r->top_k)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "seed")) {
            double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
        } else if (!strcmp(key, "stream")) {
            if (!json_bool(&p, &r->stream)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "stream_options")) {
            if (!parse_stream_options(&p, &r->stream_include_usage)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "thinking")) {
            if (!parse_thinking_control_value(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "reasoning_effort")) {
            if (!parse_reasoning_effort_value(&p, &reasoning_effort)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "think")) {
            if (!json_bool(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "stop")) {
            if (!parse_stop(&p, &r->stops)) {
                free(key);
                goto bad;
            }
        } else if (!json_skip_value(&p)) {
            free(key);
            goto bad;
        }
        free(key);
        json_ws(&p);
        if (*p == ',') p++;
        json_ws(&p);
    }
    if (*p != '}') goto bad;
    if (!got_messages) {
        snprintf(err, errlen, "missing messages");
        chat_msgs_free(&msgs);
        free(tool_schemas);
        request_free(r);
        return false;
    }
    r->has_tools = tool_schemas && tool_schemas[0] && !tool_choice_none;
    if (!got_thinking && model_alias_disables_thinking(r->model)) thinking_enabled = false;
    if (!got_thinking && model_alias_enables_thinking(r->model)) thinking_enabled = true;
    r->think_mode = ds4_think_mode_for_context(
        think_mode_from_enabled(thinking_enabled, reasoning_effort), ctx_size);
    kv_cache_restore_tool_memory_for_messages(s, &msgs);
    tool_memory_attach_to_messages(s, &msgs, &r->tool_replay);
    const char *active_tool_schemas = r->has_tools ? tool_schemas : NULL;
    r->prompt_preserves_reasoning =
        chat_history_uses_tool_context(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
        } else if (!strcmp(key, "stream")) {
            if (!json_bool(&p, &r->stream)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "stream_options")) {
            if (!parse_stream_options(&p, &r->stream_include_usage)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "thinking")) {
            if (!parse_thinking_control_value(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "reasoning_effort")) {
            if (!parse_reasoning_effort_value(&p, &reasoning_effort)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "think")) {
            if (!json_bool(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "stop")) {
            if (!parse_stop(&p, &r->stops)) {
                free(key);
                goto bad;
            }
        } else if (!json_skip_value(&p)) {
            free(key);
            goto bad;
        }
        free(key);
        json_ws(&p);
        if (*p == ',') p++;
        json_ws(&p);
    }
    if (*p != '}') goto bad;
    if (!got_messages) {
        snprintf(err, errlen, "missing messages");
        chat_msgs_free(&msgs);
        free(tool_schemas);
        request_free(r);
        return false;
    }
    r->has_tools = tool_schemas && tool_schemas[0] && !tool_choice_none;
    if (!got_thinking && model_alias_disables_thinking(r->model)) thinking_enabled = false;
    if (!got_thinking && model_alias_enables_thinking(r->model)) thinking_enabled = true;
    r->think_mode = ds4_think_mode_for_context(
        think_mode_from_enabled(thinking_enabled, reasoning_effort), ctx_size);
    kv_cache_restore_tool_memory_for_messages(s, &msgs);
    tool_memory_attach_to_messages(s, &msgs, &r->tool_replay);
    const char *active_tool_schemas = r->has_tools ? tool_schemas : NULL;
    r->prompt_preserves_reasoning =
        chat_history_uses_tool_context(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
        } else if (!strcmp(key, "stream")) {
            if (!json_bool(&p, &r->stream)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "stream_options")) {
            if (!parse_stream_options(&p, &r->stream_include_usage)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "thinking")) {
            if (!parse_thinking_control_value(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "reasoning_effort")) {
            if (!parse_reasoning_effort_value(&p, &reasoning_effort)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "think")) {
            if (!json_bool(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "stop")) {
            if (!parse_stop(&p, &r->stops)) {
                free(key);
                goto bad;
            }
        } else if (!json_skip_value(&p)) {
            free(key);
            goto bad;
        }
        free(key);
        json_ws(&p);
        if (*p == ',') p++;
        json_ws(&p);
    }
    if (*p != '}') goto bad;
    if (!got_messages) {
        snprintf(err, errlen, "missing messages");
        chat_msgs_free(&msgs);
        free(tool_schemas);
        request_free(r);
        return false;
    }
    r->has_tools = tool_schemas && tool_schemas[0] && !tool_choice_none;
    if (!got_thinking && model_alias_disables_thinking(r->model)) thinking_enabled = false;
    if (!got_thinking && model_alias_enables_thinking(r->model)) thinking_enabled = true;
    r->think_mode = ds4_think_mode_for_context(
        think_mode_from_enabled(thinking_enabled, reasoning_effort), ctx_size);
    kv_cache_restore_tool_memory_for_messages(s, &msgs);
    tool_memory_attach_to_messages(s, &msgs, &r->tool_replay);
    const char *active_tool_schemas = r->has_tools ? tool_schemas : NULL;
    r->prompt_preserves_reasoning =
        chat_history_uses_tool_context(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Trova bug sottili e spiega quali invarianti dell'inferenza possono rompersi.

File: ds4_server.c

```c
double v = 0.0;
            if (!json_number(&p, &v)) {
                free(key);
                goto bad;
            }
            r->seed = v > 0.0 ? (uint64_t)v : 0;
        } else if (!strcmp(key, "stream")) {
            if (!json_bool(&p, &r->stream)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "stream_options")) {
            if (!parse_stream_options(&p, &r->stream_include_usage)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "thinking")) {
            if (!parse_thinking_control_value(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "reasoning_effort")) {
            if (!parse_reasoning_effort_value(&p, &reasoning_effort)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "think")) {
            if (!json_bool(&p, &thinking_enabled)) {
                free(key);
                goto bad;
            }
            got_thinking = true;
        } else if (!strcmp(key, "stop")) {
            if (!parse_stop(&p, &r->stops)) {
                free(key);
                goto bad;
            }
        } else if (!json_skip_value(&p)) {
            free(key);
            goto bad;
        }
        free(key);
        json_ws(&p);
        if (*p == ',') p++;
        json_ws(&p);
    }
    if (*p != '}') goto bad;
    if (!got_messages) {
        snprintf(err, errlen, "missing messages");
        chat_msgs_free(&msgs);
        free(tool_schemas);
        request_free(r);
        return false;
    }
    r->has_tools = tool_schemas && tool_schemas[0] && !tool_choice_none;
    if (!got_thinking && model_alias_disables_thinking(r->model)) thinking_enabled = false;
    if (!got_thinking && model_alias_enables_thinking(r->model)) thinking_enabled = true;
    r->think_mode = ds4_think_mode_for_context(
        think_mode_from_enabled(thinking_enabled, reasoning_effort), ctx_size);
    kv_cache_restore_tool_memory_for_messages(s, &msgs);
    tool_memory_attach_to_messages(s, &msgs, &r->tool_replay);
    const char *active_tool_schemas = r->has_tools ? tool_schemas : NULL;
    r->prompt_preserves_reasoning =
        chat_history_uses_tool_context(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
```<｜Assistant｜><think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
    ds4_tokenize_rendered_chat(e, r->prompt_text, &r->prompt);
    chat_msgs_free(&msgs);
    free(tool_schemas);
    return true;
bad:
    chat_msgs_free(&msgs);
    free(tool_schemas);
    snprintf(err, errlen, "invalid JSON request");
    request_free(r);
    return false;
}

static bool parse_anthropic_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                                    int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    r->api = API_ANTHROPIC;
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *system = NULL;
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_anthropic_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "system")) {
            free(system);
            if (!parse_anthropic_system(&p, &system)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '{') {
                p++;
                json_ws(&p);
                while (*p && *p != '}') {
                    char *ckey = NULL;
                    if (!json_string(&p, &ckey)) {
                        free(key);
                        goto bad;
                    }
                    json_ws(&p);
                    if (*p != ':') {
                        free(ckey);
                        free(key);
                        goto bad;
                    }
                    p++;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
    ds4_tokenize_rendered_chat(e, r->prompt_text, &r->prompt);
    chat_msgs_free(&msgs);
    free(tool_schemas);
    return true;
bad:
    chat_msgs_free(&msgs);
    free(tool_schemas);
    snprintf(err, errlen, "invalid JSON request");
    request_free(r);
    return false;
}

static bool parse_anthropic_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                                    int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    r->api = API_ANTHROPIC;
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *system = NULL;
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_anthropic_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "system")) {
            free(system);
            if (!parse_anthropic_system(&p, &system)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '{') {
                p++;
                json_ws(&p);
                while (*p && *p != '}') {
                    char *ckey = NULL;
                    if (!json_string(&p, &ckey)) {
                        free(key);
                        goto bad;
                    }
                    json_ws(&p);
                    if (*p != ':') {
                        free(ckey);
                        free(key);
                        goto bad;
                    }
                    p++;
```<｜Assistant｜></think>


[System] You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.

[User]
Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
    ds4_tokenize_rendered_chat(e, r->prompt_text, &r->prompt);
    chat_msgs_free(&msgs);
    free(tool_schemas);
    return true;
bad:
    chat_msgs_free(&msgs);
    free(tool_schemas);
    snprintf(err, errlen, "invalid JSON request");
    request_free(r);
    return false;
}

static bool parse_anthropic_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                                    int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    r->api = API_ANTHROPIC;
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *system = NULL;
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_anthropic_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "system")) {
            free(system);
            if (!parse_anthropic_system(&p, &system)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '{') {
                p++;
                json_ws(&p);
                while (*p && *p != '}') {
                    char *ckey = NULL;
                    if (!json_string(&p, &ckey)) {
                        free(key);
                        goto bad;
                    }
                    json_ws(&p);
                    if (*p != ':') {
                        free(ckey);
                        free(key);
                        goto bad;
                    }
                    p++;
```

<｜begin▁of▁sentence｜>You are DeepSeek V4 Flash running locally. Answer accurately, preserve technical details, and use tools only when the prompt asks for tool use.<｜User｜>Review this excerpt for correctness risks, memory lifetime issues, and performance bottlenecks.

File: ds4_server.c

```c
(&msgs, active_tool_schemas);
    r->prompt_text = render_chat_prompt_text(&msgs, active_tool_schemas,
                                             &r->tool_orders, r->think_mode);
    ds4_tokenize_rendered_chat(e, r->prompt_text, &r->prompt);
    chat_msgs_free(&msgs);
    free(tool_schemas);
    return true;
bad:
    chat_msgs_free(&msgs);
    free(tool_schemas);
    snprintf(err, errlen, "invalid JSON request");
    request_free(r);
    return false;
}

static bool parse_anthropic_request(ds4_engine *e, server *s, const char *body, int def_tokens,
                                    int ctx_size, request *r, char *err, size_t errlen) {
    request_init(r, REQ_CHAT, def_tokens);
    r->api = API_ANTHROPIC;
    const char *p = body;
    bool got_messages = false;
    bool tool_choice_none = false;
    bool got_thinking = false;
    bool thinking_enabled = true;
    ds4_think_mode reasoning_effort = DS4_THINK_HIGH;
    chat_msgs msgs = {0};
    char *system = NULL;
    char *tool_schemas = NULL;

    json_ws(&p);
    if (*p != '{') goto bad;
    p++;
    json_ws(&p);
    while (*p && *p != '}') {
        char *key = NULL;
        if (!json_string(&p, &key)) goto bad;
        json_ws(&p);
        if (*p != ':') {
            free(key);
            goto bad;
        }
        p++;
        if (!strcmp(key, "messages")) {
            chat_msgs_free(&msgs);
            if (!parse_anthropic_messages(&p, &msgs)) {
                free(key);
                goto bad;
            }
            got_messages = true;
        } else if (!strcmp(key, "system")) {
            free(system);
            if (!parse_anthropic_system(&p, &system)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tools")) {
            free(tool_schemas);
            tool_schemas = NULL;
            if (!parse_tools_value(&p, &tool_schemas, &r->tool_orders)) {
                free(key);
                goto bad;
            }
        } else if (!strcmp(key, "tool_choice")) {
            json_ws(&p);
            if (*p == '{') {
                p++;
                json_ws(&p);
                while (*p && *p != '}') {
                    char *ckey = NULL;
                    if (!json_string(&p, &ckey)) {
                        free(key);
                        goto bad;
                    }
                    json_ws(&p);
                    if (*p != ':') {
                        free(ckey);
                        free(key);
                        goto bad;
                    }
                    p++;
```<｜Assistant｜><think>