Bug: Incomplete JSON stream in OpenCode using gpt-5.3-codex (Unterminated string) #20599

Description

Description / 问题描述

[CN] 在使用 OpenCode 配合 gpt-5.3-codex 模型时，偶尔会遇到 JSON 解析失败的情况。
[EN] Occasional JSON parsing failures occur when using OpenCode with the gpt-5.3-codex model.

[CN] 报错信息显示为 JSON Parse error: Unterminated string，通常发生在模型尝试调用工具（Tools）或解析复杂上下文时。
[EN] The error message JSON Parse error: Unterminated string appears, typically when the model attempts tool-calls or processes complex contexts.

Actual Behavior / 实际现象

1. [CN] AI 响应中途停止，界面弹出原始日志。
   [EN] AI response stops mid-way, and raw logs are displayed on the UI.
2. [CN] 日志显示 JSON 在传输过程中被截断（例如在 tools 定义部分）。
   [EN] Logs show the JSON payload is truncated during streaming (e.g., within the tools definition).

Environment / 环境

• Model: gpt-5.3-codex
• Platform: OpenCode-web

Repository / 项目仓库

• Link: https://github.com/deretame/async_uv
• Context: This is an open-source project. The issue occurs frequently when Codex tries to index or analyze the root directory of this repository.
  （这是一个开源项目。当 Codex 尝试索引或分析该仓库的根目录时，此问题频繁发生。）

// --- [LOG START: METADATA RETAINED] ---
{
  "type": "response.created",
  "response": {
    "id": "resp_029c556764108ed40169cddc15a8b481919f76008087e8f49a",
    "model": "gpt-5.3-codex",
    "status": "in_progress",
    "parallel_tool_calls": true,
    "safety_identifier": "user-p1NpZeckCsXyN2GZOfJyhtLI",
    "tools": [
      {
        "type": "function",
        "name": "question",
        "description": "Use this tool when you need to ask the user questions..."
        // ... (full schema for 'question' retained)
      },
      {
        "type": "function",
        "name": "bash",
        "description": "Executes a given bash command in a persistent shell session...",
        "parameters": {
          "type": "object",
          "properties": {
            "command": { "type": "string" },
            "workdir": { "default": "/home/windy/pack/async_uv" }
          }
        }
      },
      
      // --- [STRATEGIC TRUNCATION: 15+ TOOLS REMOVED TO FIT 64KB LIMIT] ---
      
      {
        "type": "function",
        "name": "context7_query-docs",
        "description": "Retrieves and queries up-to-date documentation..."
      }
    ]
  }
}

// --- [CRITICAL ERROR AT THE END OF STREAM] ---
// JSON parsing failed: Text: {"type":"response
// Error message: JSON Parse error: Unterminated string

Plugins

none

OpenCode version

1.3.13 web

Steps to reproduce

## Steps to Reproduce / 复现步骤

[EN] This issue occurs frequently (intermittently) during normal usage.
[CN] 此问题在日常使用中非常高频（且具有一定的随机性）。

1. Open a project with many files (e.g., my async_uv workspace).
   打开一个包含较多文件的项目（例如我的 async_uv 工作区）。
2. Upload an image or provide a complex prompt that triggers Codex tool-calls (e.g., "Analyze this image").
   上传一张图片或输入复杂的指令，触发 Codex 的工具调用逻辑（例如：“解析这张图”）。
3. Wait for the streaming response.
   等待流式响应输出。
4. Result: The response often halts mid-stream, popping up the JSON Parse error.
   结果： 响应经常在传输中途断开，并弹出 JSON 解析错误。

Screenshot and/or share link

https://opncd.ai/share/IgyV5Okb

Operating System

PRETTY_NAME="Debian GNU/Linux 13 (trixie)" NAME="Debian GNU/Linux" VERSION_ID="13" VERSION="13 (trixie)" VERSION_CODENAME=trixie DEBIAN_VERSION_FULL=13.4 ID=debian HOME_URL="https://www.debian.org/" SUPPORT_URL="https://www.debian.org/support" BUG_REPORT_URL="https://bugs.debian.org/"

Terminal

Windows Terminal, wsl2, fish