Free-ZAI-Api

Self-hosted OpenAI-compatible API proxy for chat.z.ai (GLM-5.3 / GLM-5.2 / etc). Runs a real browser session via Playwright, so the site sees a genuine Chrome fingerprint — the invisible Aliyun captcha passes automatically, no third-party captcha services needed.

Built for use with opencode and any other OpenAI-compatible client.

How it works

client (opencode)                proxy (main.py)                  chat.z.ai
      │  POST /v1/chat/completions     │                               │
      │  {tools, messages, ...}        │                               │
      ├───────────────────────────────>│  Playwright browser session   │
      │                                ├──────────────────────────────>│
      │                                │   fresh chat + model select   │
      │                                │   invisible captcha auto-pass │
      │                                │<──────────────────────────────┤
      │<───────────────────────────────┤  SSE stream                   │
      │  OpenAI chunks                 │  (reasoning_content + content)│

• Tool calling — z.ai has no native function-calling over web chat, so the proxy injects tool schemas into the prompt and streams back the model's <tc>{json}</tc> responses as standard OpenAI delta.tool_calls (z.ai strips native <tool_call> tags from the stream, hence the custom tag).
• Account rotation — round-robin between accounts from accounts.json.
• Cooldown — configurable delay between requests to avoid triggering captchas.
• Popups — promotional dialogs are closed automatically by a background watcher.

Install

git clone https://github.com/lothiann/Free-ZAI-Api.git
cd Free-ZAI-Api
pip install -r requirements.txt
playwright install chromium

Configure accounts

Get your auth token: open https://chat.z.ai → DevTools (F12) → Console:

fetch('/api/v1/auths/').then(r=>r.json()).then(d=>window.__acc={id:d.id,email:d.email,name:d.name,token:d.token})

copy(JSON.stringify(__acc))

Paste into accounts.json:

{
  "rotate_every": 10,
  "accounts": [
    { "name": "main", "email": "you@gmail.com", "token": "eyJ..." }
  ]
}

Field	Description
token	JWT from DevTools (required)
rotate_every	requests per account before switching to the next one

Run

python main.py

Server starts on http://127.0.0.1:8492/v1.

Test

curl http://127.0.0.1:8492/v1/models

curl -N http://127.0.0.1:8492/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d "{\"model\":\"glm-5.2\",\"stream\":true,\"messages\":[{\"role\":\"user\",\"content\":\"say OK\"}]}"

# account status
curl http://127.0.0.1:8492/accounts

opencode

Add to ~/.config/opencode/opencode.jsonc (or opencode.json):

{
  "provider": {
    "zai": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Z.AI (browser proxy)",
      "options": {
        "baseURL": "http://127.0.0.1:8492/v1",
        "apiKey": "sk-nothing"
      },
      "models": {
        "glm-5.2": { "name": "GLM-5.2", "reasoning": true }
      }
    }
  }
}

Models can also be discovered automatically from /v1/models, but listing them manually is more reliable. The reasoning: true flag enables default/high/max thinking-effort variants (mapped to the site's Deep Think control).

Endpoints

Endpoint	Description
GET /v1/models	model list parsed from the site
POST /v1/chat/completions	chat, streaming & non-streaming, with tools
GET /accounts	rotation status

Notes

• Each request opens a fresh site chat; full conversation history is forwarded as a single prompt.
• Reasoning is streamed via delta.reasoning_content, the answer via delta.content.
• Tool calls require the client to send standard OpenAI tools; results come back as role: "tool" messages.
• Logs are written to logs/, the last raw response to last_response.json.

Disclaimer

For personal / educational use. Automating chat.z.ai may violate its Terms of Service — use your own accounts at your own risk.