Gemini Web 2 API

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Gemini Web 2 API is a lightweight Go proxy that exposes OpenAI-compatible /v1/chat/completions and /v1/models endpoints while forwarding requests to the Gemini web experience. It supports streaming responses, session continuity, token refresh, and a small telemetry endpoint for the built-in WebUI.

Highlights

• OpenAI-compatible chat and model endpoints
• Streaming SSE responses
• Session reuse with X-Session-ID or conversation_id
• Optional proxy and cookie-based token refresh
• Telemetry endpoint at /api/telemetry
• Embedded dashboard at / and manual page at /help
• WebUI defaults to English and can switch to Chinese

Quick Start

1. Enter the project directory:

cd e:/Project/AI/All2API/geminiweb2api

2. Install dependencies and run:

go mod tidy
go run ./cmd/geminiweb2api

Project layout now uses folders by responsibility:

• cmd/geminiweb2api: application entrypoint
• internal/server: HTTP server assembly and routing
• internal/gemini: Gemini request/response logic
• internal/config, internal/logging, internal/httpclient, internal/token, internal/metrics: infrastructure modules
• internal/web: embedded dashboard and help pages

3. Default listen address:

• http://127.0.0.1:8080

4. Verify the service:

curl -s "http://127.0.0.1:8080/api/telemetry"
curl -s "http://127.0.0.1:8080/v1/models" \
  -H "Authorization: Bearer your-api-key-here"

Configuration

Use config.json in the project root:

{
  "api_key": "your-api-key-here",
  "token": "",
  "cookies": "",
  "tokens": null,
  "proxy": "",
  "gemini_url": "",
  "gemini_home_url": "",
  "port": 8080,
  "log_file": "",
  "log_level": "info",
  "note": [
    "Auto-generated config"
  ]
}

Config Fields

• api_key Protects this local service. Clients must send Authorization: Bearer <api_key>.
• token Manual SNlM0e fallback token for Gemini web when automatic fetch fails.
• cookies Gemini web cookie string. Recommended when anonymous access is unstable or the environment requires sign-in state.
• tokens Reserved field. Currently unused.
• proxy Explicit proxy such as http://127.0.0.1:7890. The app also respects HTTP_PROXY, HTTPS_PROXY, and ALL_PROXY.
• gemini_url Override for the Gemini generation endpoint in reverse-proxy setups.
• gemini_home_url Override for the Gemini homepage used for token discovery.
• port Local listen port, default 8080.
• log_file Log output path. Empty means stdout.
• log_level debug, info, warn, or error.
• note Free-form note strings surfaced by /api/telemetry and the WebUI.

Hot Reload

The process checks config.json every 5 seconds and reloads it automatically when the file changes. You do not need to restart the service after editing the config.

Token and Cookies

Automatic mode

• The service tries to fetch the anonymous Gemini token (SNlM0e) from the Gemini homepage by default.
• You can often run without cookies, but adding them improves stability.

Manual token mode

When automatic fetch fails:

1. Open https://gemini.google.com/ or your configured gemini_home_url.
2. Open browser devtools.
3. Search for SNlM0e in Elements, Sources, or Network.
4. Copy the value after "SNlM0e":"...".
5. Put it into config.json:

{
  "token": "SNlM0e-example-value"
}

Cookies

If your environment needs a logged-in browser session or you see protection pages:

1. Open Gemini in a working browser session.
2. Open devtools and find the cookie store.
3. Copy the full cookie string:

SID=...; APISID=...; SAPISID=...; ...

4. Put it into config.json:

{
  "cookies": "SID=...; APISID=...; SAPISID=...; ..."
}

Do not commit real cookies to a public repository.

Usage Examples

Health check

curl -s "http://127.0.0.1:8080/api/telemetry"

Model list

curl -s "http://127.0.0.1:8080/v1/models" \
  -H "Authorization: Bearer your-api-key-here"

Non-stream chat

curl -s "http://127.0.0.1:8080/v1/chat/completions" \
  -H "Authorization: Bearer your-api-key-here" \
  -H "Content-Type: application/json" \
  -H "X-Session-ID: demo-session" \
  -d '{
    "model": "gemini-3-flash",
    "stream": false,
    "messages": [
      {"role": "system", "content": "You are a helpful assistant"},
      {"role": "user", "content": "Please introduce yourself."}
    ]
  }'

Streaming SSE

curl -N "http://127.0.0.1:8080/v1/chat/completions" \
  -H "Authorization: Bearer your-api-key-here" \
  -H "Content-Type: application/json" \
  -H "X-Session-ID: demo-session" \
  -d '{
    "model": "gemini-3-flash",
    "stream": true,
    "messages": [
      {"role": "user", "content": "Introduce yourself in three sentences."}
    ]
  }'

Session Continuity

• Keep X-Session-ID stable for the same user or conversation.
• The service will reuse Gemini-side session context for better multi-turn continuity.

Troubleshooting

• Gemini access fails or times out: Check proxy first, then system proxy environment variables.
• HTML, captcha, or protection pages appear: Try cookies, change IP/proxy, and enable debug logging.
• Conversation continuity is broken: Reuse the same X-Session-ID.
• Automatic token fetch fails: Manually set token, or verify that cookies are valid and not expired.

WebUI

• GET / renders the dashboard
• GET /help renders the manual page
• Theme and language preferences are stored in local storage
• Default language is English, with a Chinese switch available in the UI