codexia 1.0.1

OpenAI- and Anthropic-compatible local API gateway backed by Codex OAuth.
Documentation

codexia

CI Release

Rust gateway that logs in with OpenAI Codex OAuth and exposes OpenAI- and Anthropic-compatible APIs.

Usage

cargo install codexia
codexia login
codexia config
codexia serve

# later, update to the latest published release
codexia update

login prints the Codex OAuth URL. Complete the login in a browser, then paste the full redirected URL from the browser address bar, for example http://localhost:1455/auth/callback?code=...&state=.... This matches OpenClaw's remote/headless fallback and does not require the gateway host to be reachable from the public internet.

OpenAI-compatible chat request:

curl http://127.0.0.1:14550/v1/chat/completions \
  -H 'content-type: application/json' \
  -d '{
    "model": "gpt-5.5",
    "messages": [{"role": "user", "content": "hello"}]
  }'

Anthropic-compatible Messages request:

curl http://127.0.0.1:14550/v1/messages \
  -H 'content-type: application/json' \
  -H 'x-api-key: local-secret' \
  -H 'anthropic-version: 2023-06-01' \
  -d '{
    "model": "gpt-5.5",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "hello"}]
  }'

Claude Code / Anthropic SDK setup:

export ANTHROPIC_BASE_URL=http://127.0.0.1:14550
export ANTHROPIC_AUTH_TOKEN=local-secret
export ANTHROPIC_MODEL="gpt-5.5"
claude

ANTHROPIC_BASE_URL should point at the Codexia server root, not /v1, because Anthropic clients append /v1/messages themselves.

Minimal Claude Code flow:

codexia login
codexia serve --bind 127.0.0.1:14550 --api-key local-secret

export ANTHROPIC_BASE_URL=http://127.0.0.1:14550
export ANTHROPIC_AUTH_TOKEN=local-secret
export ANTHROPIC_MODEL="gpt-5.5"

claude

For non-interactive validation, this works:

ANTHROPIC_BASE_URL=http://127.0.0.1:14550 \
ANTHROPIC_AUTH_TOKEN=local-secret \
ANTHROPIC_MODEL="gpt-5.5" \
claude -p "Reply with the single word OK"

If Claude Code or its explore/sub-agent path still emits Anthropic-native model ids such as claude-sonnet-*, enable a local fallback:

CODEXIA_MODEL_FALLBACK=gpt-5.5 codexia serve --api-key local-secret

Codexia then rewrites known unsupported Anthropic model ids to the configured fallback before calling Codex.

Common pitfalls:

  • Do not set ANTHROPIC_BASE_URL to http://127.0.0.1:14550/v1; Claude Code appends /v1/messages itself.
  • Use a model that /v1/models actually returns, such as gpt-5.5. If Claude Code defaults to claude-sonnet-*, the request will fail because Codexia proxies Codex models, not Anthropic-hosted model IDs.
  • ANTHROPIC_AUTH_TOKEN is only the local gateway key configured with --api-key; it is not your upstream OpenAI/Codex OAuth token.
  • If you prefer a background service, install the daemon first and then point ANTHROPIC_BASE_URL at the daemon address instead of running codexia serve manually.

Optional local API key protection:

CODEXIA_API_KEY=local-secret codexia serve
curl http://127.0.0.1:14550/v1/models -H 'authorization: Bearer local-secret'

You can combine it with the model fallback when running Claude Code against the gateway:

CODEXIA_API_KEY=local-secret \
CODEXIA_MODEL_FALLBACK=gpt-5.5 \
codexia serve

Interactive runtime configuration:

codexia config
codexia config show
codexia config reset

The config file is stored at ~/.codexia/config.json by default and is used as the fallback source for codexia serve and codexia daemon install.

Refresh the stored Codex OAuth token while the server is running:

curl -X POST http://127.0.0.1:14550/v1/auth/refresh \
  -H 'authorization: Bearer local-secret'

Check token expiry, account metadata, and rate-limit windows:

codexia status

Fetch the same status data over HTTP:

curl http://127.0.0.1:14550/v1/status \
  -H 'authorization: Bearer local-secret'

Example response:

{
  "account_id": "acc_123",
  "token": {
    "expires_at": 1778098507,
    "remaining_seconds": 813427,
    "expires_at_local": "2026-05-05 12:15:07 +08:00"
  },
  "account": {
    "name": "Personal",
    "email": "user@example.com",
    "structure": "personal",
    "plan": "chatgptpro",
    "has_active_subscription": true,
    "subscription_expires_at": "2026-05-11T15:16:00+00:00",
    "subscription_expires_at_local": "2026-05-11 23:16:00 +08:00",
    "subscription_remaining_seconds": 1212345
  },
  "credits_balance": 0,
  "rate_limits": [
    {
      "name": "5h",
      "remaining_percent": 97.0,
      "reset_at": "1777297264",
      "reset_at_local": "2026-04-27 21:41:04 +08:00",
      "reset_in_seconds": 8658
    },
    {
      "name": "weekly",
      "remaining_percent": 68.0,
      "reset_at": "1777400385",
      "reset_at_local": "2026-04-29 02:19:45 +08:00",
      "reset_in_seconds": 111779
    }
  ],
  "warnings": []
}

Install Codexia as a per-user background daemon:

codexia daemon install
codexia daemon reinstall
codexia daemon start
codexia daemon status
codexia daemon restart
codexia daemon stop
codexia daemon uninstall

On macOS, Codexia installs a LaunchAgent at ~/Library/LaunchAgents/com.codexia.daemon.plist. On Linux, it installs a systemd user unit at ~/.config/systemd/user/codexia.service. Windows does not currently implement native daemon/service management; use WSL and run the Linux build there if you need codexia daemon commands.

On Linux, inspect the per-user service with:

codexia daemon status
systemctl --user status codexia.service

The daemon runs codexia serve with the options passed at install time:

codexia daemon install \
  --bind 127.0.0.1:14550 \
  --api-key local-secret

Models returned by /v1/models default to OpenClaw's openai-codex registry:

gpt-5.1
gpt-5.1-codex-max
gpt-5.1-codex-mini
gpt-5.2
gpt-5.2-codex
gpt-5.3-codex
gpt-5.3-codex-spark
gpt-5.4
gpt-5.4-mini
gpt-5.5

Credentials are stored at ~/.codexia/auth.json by default. Override with --auth-file, CODEXIA_AUTH_FILE, or CODEXIA_HOME.

Runtime config also supports an optional model_fallback value, and the CLI accepts --model-fallback / CODEXIA_MODEL_FALLBACK.

OpenAI compatibility currently covers:

  • GET /v1/models
  • POST /v1/chat/completions
  • POST /v1/responses
  • POST /v1/images/generations
  • POST /v1/responses/compact
  • POST /v1/responses/input_tokens

On POST /v1/chat/completions, Codexia accepts common OpenAI compatibility fields such as temperature, max_tokens, max_completion_tokens, and max_output_tokens, but the current Codex upstream rejects those parameters. Codexia therefore accepts them without error and omits them from the upstream Codex request, so they should be treated as compatibility no-ops rather than effective sampling or output-length controls.

/v1/responses currently supports previous_response_id only as an in-memory continuation mechanism within the same running Codexia process. It is not exposed as a public retrievable/deletable response resource, and it should not be treated as durable storage across daemon restarts or process exits.

Image generation is exposed in two compatibility shapes:

  • OpenAI-style POST /v1/images/generations
  • OpenAI Responses hosted tool {"type":"image_generation"}

Current image-generation caveats:

  • OpenAI POST /v1/responses supports streaming image-generation events
  • POST /v1/images/generations remains non-streaming
  • Anthropic POST /v1/messages image generation streaming is exposed as a Codexia extension that emits image content blocks only once the upstream response completes
  • generated images are returned as base64 payloads
  • Anthropic compatibility uses a Codexia extension that returns content: [{"type":"image","source":{"type":"base64",...}}] on POST /v1/messages when the request includes a tool named image_generation

Anthropic compatibility currently covers:

  • GET /v1/models with an anthropic-version header
  • POST /v1/messages
  • POST /v1/messages/count_tokens
  • POST /v1/messages/batches
  • GET /v1/messages/batches
  • GET /v1/messages/batches/{batch_id}
  • POST /v1/messages/batches/{batch_id}/cancel
  • DELETE /v1/messages/batches/{batch_id}
  • GET /v1/messages/batches/{batch_id}/results
  • x-api-key or authorization: Bearer ... local auth
  • Anthropic-style SSE events for streaming text and tool use

Message batches execute asynchronously in a background task. Cancellation is best-effort at request boundaries inside the batch worker: requests that have already started are allowed to finish, while not-yet-started requests are marked as canceled.

The implementation intentionally follows Ollama's compatibility strategy where possible: Anthropic headers are accepted, locally configured auth is enforced, and unsupported advanced Anthropic-only features are ignored rather than rejected when possible.

The OAuth flow follows OpenClaw/pi-ai's Codex flow: PKCE, manual paste of the http://localhost:1455/auth/callback?... redirect URL, token exchange at https://auth.openai.com/oauth/token, and Codex requests to https://chatgpt.com/backend-api/codex/responses.

Disclaimer

Codexia is an unofficial compatibility tool. It is not affiliated with, endorsed by, or supported by OpenAI or Anthropic.

You are responsible for making sure your usage complies with the terms, policies, account restrictions, and data-handling obligations that apply to your upstream account and deployment environment. In particular, do not assume that personal OAuth-backed access can be shared, resold, or safely exposed as a multi-user hosted service. The LGPLv3 license for this repository does not change those upstream restrictions.

License

Copyright (c) 2026 Codexia contributors.

Licensed under the GNU Lesser General Public License v3.0 only. See LICENSE.