pi-opencode-zen

🚫 DEPRECATED — THIS EXTENSION NO LONGER WORKS

Status: UNUSABLE since 2026-09-23. Do NOT install.

OpenCode Zen shut down anonymous free-tier access on its public API for all non-official clients (FreeTierError: "OpenCode's free tier can only be used from within OpenCode"). This cannot be bypassed by any headers or client emulation — the official opencode v2 client uses a private, server-dispatched endpoint. The only remaining access path is a paid API key ($20 prepaid, pay-per-request), which contradicts this extension's free-access purpose.

• If you installed this before 2026-09-23: remove it with pi remove npm:pi-opencode-zen
• For free models in pi, use providers with a genuine free tier (e.g. OpenRouter :free models, Groq, Google AI Studio)
• Full post-mortem (Chinese): pi-tutor tutorial #12 — anti-forgery engineering

以下为历史文档，扩展已不可用。/ Everything below is historical documentation.

English | 简体中文

(Historical) Use OpenCode Zen's free models (e.g. nemotron-3.5-lightning-free, mimo-v2.5-free) inside the pi coding agent. No API key, no account, no login. — This stopped working on 2026-09-23, see notice above.

Install

Install via npm (recommended):

pi install npm:pi-opencode-zen

Or install directly from GitHub:

pi install git:github.com/Feng-H/pi-opencode-zen

Zero config — after installing, switch models with /model inside pi and pick a free model under opencode-zen.

How it works

OpenCode Zen exposes an OpenAI-compatible endpoint at https://opencode.ai/zen/v1. As of 2026-09 it grants free-tier access when a request:

• carries an empty Authorization: Bearer header (any non-empty invalid token is rejected with 401), and
• includes an x-session-id header — without it, Zen rejects with MissingSessionID: OpenCode's free tier can only be used in OpenCode. The extension generates one stable UUID per client startup, which is sufficient.

The extension registers an opencode-zen provider that points pi at the Zen endpoint, sets both headers, and fetches the live model list from /models at startup (falling back to a static list on failure).

Models

Fetched dynamically; only free models (id containing -free) are registered. Current pool (verified 2026-09-15):

| Model | Reasoning | Notes | |-------|-----------|-------| | nemotron-3.5-lightning-free | yes | verified working | | nemotron-3-ultra-free | yes | | | mimo-v2.5-free | yes | often rate-limited | | muse-spark-1.3-contributor-free | no | currently 500s upstream | | muse-spark-1.2-contributor-free | no | currently 500s upstream | | ling-3.0-flash-fin-free | no | Ant Ling (finance-tuned) | | deepseek-v4-flash-free | — | retired upstream |

The pool rotates: new -free models appear automatically; individual models may be rate-limited or unavailable at any time — try another one.

中文说明

在 pi 中使用 OpenCode Zen 的免费模型（如 nemotron-3.5-lightning-free、mimo-v2.5-free）。无需 API key、无需注册、无需登录。

⚠️ 2026-09-23 匿名免费层关闭（v0.4.0）

OpenCode Zen 公共端点 (/zen/v1) 的匿名免费层已对非官方客户端关闭：任何非 opencode v2 客户端的请求都会收到 FreeTierError: OpenCode's free tier can only be used from within OpenCode（与 headers/指纹无关，官方 v2 走 Console 内部路由）。API key 通道独立且不受此限制。

配置方法：在 Zen Console 注册获取 API key，然后：

# shell 配置里加
export OPENCODE_API_KEY="sk-你的key"

无 key 时扩展仍会注册（models 列表可拉取），但 provider 名称会标注 key missing，实际对话会被 Zen 拒绝。

安装方式

通过 npm 官方镜像 安装（推荐）：

pi install npm:pi-opencode-zen

或者直接从 GitHub 安装：

pi install git:github.com/Feng-H/pi-opencode-zen

• npm 官方包页面：https://www.npmjs.com/package/pi-opencode-zen

零配置 —— 装好后 pi 对话里 /model 切换,选 opencode-zen 下的免费模型即可。

工作原理

OpenCode Zen 提供 OpenAI 兼容端点 https://opencode.ai/zen/v1。2026-09 起免费访问需同时满足:

• Authorization: Bearer （空 Bearer —— 填任何非空无效 token 反而被 401 拒绝）;
• 携带 x-session-id 请求头 —— 缺了直接报 MissingSessionID: OpenCode's free tier can only be used in OpenCode。扩展每次启动生成一个稳定 UUID 即可满足。

扩展注册 opencode-zen provider,带上上述两个头,启动时从 /models 动态拉取模型列表（失败则回退静态列表）。

模型

动态拉取,只注册 id 含 -free 的免费模型（非免费模型匿名访问会被 401）。当前免费池（2026-09-15 实测）:

| 模型 | 推理 | 说明 | |-------|-----------|-------| | nemotron-3.5-lightning-free | 是 | 实测可用 | | nemotron-3-ultra-free | 是 | | | mimo-v2.5-free | 是 | 经常限流 | | muse-spark-1.3-contributor-free | 否 | 上游目前 500 | | muse-spark-1.2-contributor-free | 否 | 上游目前 500 | | ling-3.0-flash-fin-free | 否 | 蚂蚁 Ling（金融向） | | deepseek-v4-flash-free | — | 上游已下线 |

免费池会轮换:新 -free 模型自动出现;个别模型可能随时限流或不可用 —— 换一个试即可。

限制

• 有限流:免费模型共享公共配额,不适合重度/自动化使用;
• 尽力而为:依赖第三方免费服务,策略随时可能变化（如 2026-09 的 SessionID 门禁）;
• 成本按零上报（访问本身免费）。

License

MIT