Function parse_completion_request

ds4_server.c:3991–4131

                    }
                } else if (!strcmp(key, "text")) {
                    /* The text field of a typed content block is a plain JSON
                     * string. Accept null as the empty string for parity with
                     * upstream serializers that emit null for empty blocks. */
                    json_ws(p);
                    if (json_lit(p, "null")) {
                        free(text);
                        text = xstrdup("");
                    } else if (!json_string_replace(p, &text)) {
                        free(key);
                        free(type);
                        free(text);
                        free(image_url);
                        goto fail;
                    }
                } else if (!strcmp(key, "image_url")) {
                    free(image_url);
                    image_url = NULL;
                    if (!parse_image_url_value(p, &image_url)) {
                        free(key);
                        free(type);
                        free(text);
                        goto fail;
                    }
                } else if (!json_skip_value(p)) {
                    free(key);
                    free(type);
                    free(text);
                    free(image_url);
                    goto fail;
                }
                free(key);
                json_ws(p);
                if (**p == ',') (*p)++;
                json_ws(p);
            }
            if (**p != '}') {
                free(type);
                free(text);
                free(image_url);
                goto fail;
            }
            (*p)++;
            /* Fail closed: a content object must carry a known text-like type
             * AND a text field. Anything else — missing type, missing text,
             * image/file/audio types, future schema-drift — is rejected so the
             * client gets a 400 instead of an answer built on context the
             * server discarded silently. */
            bool is_text_block = type && (
                !strcmp(type, "input_text") ||
                !strcmp(type, "output_text") ||
                !strcmp(type, "text") ||
                !strcmp(type, "summary_text") ||
                !strcmp(type, "reasoning_text"));
            bool is_image_block = type && !strcmp(type, "input_image");
            if (is_image_block) {
                char marker[SERVER_IMAGE_MARKER_BYTES];
                if (!images ||
                    !server_image_inputs_push_data_uri(images, image_url, marker)) {