Metadata-Version: 2.4 Name: ant2oai Version: 0.1.5 Summary: Lightweight Anthropic-to-OpenAI API proxy — run Claude Code with any OpenAI-compatible backend Project-URL: Homepage, https://github.com/WqyJh/a2o Project-URL: Documentation, https://github.com/WqyJh/a2o#readme Project-URL: Repository, https://github.com/WqyJh/a2o Project-URL: Issues, https://github.com/WqyJh/a2o/issues Author: WqyJh License: MIT License Copyright (c) 2025 WqyJh Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. License-File: LICENSE Keywords: anthropic,api-gateway,claude,claude-code,extended-thinking,llm,openai,proxy,sse,streaming,tool-calling Classifier: Development Status :: 4 - Beta Classifier: Framework :: AsyncIO Classifier: Intended Audience :: Developers Classifier: License :: OSI Approved :: MIT License Classifier: Operating System :: OS Independent Classifier: Programming Language :: Python :: 3 Classifier: Programming Language :: Python :: 3.11 Classifier: Programming Language :: Python :: 3.12 Classifier: Programming Language :: Python :: 3.13 Classifier: Topic :: Internet :: Proxy Servers Classifier: Topic :: Software Development :: Libraries Classifier: Typing :: Typed Requires-Python: >=3.11 Requires-Dist: fastapi>=0.115 Requires-Dist: httpx>=0.28 Requires-Dist: uvicorn[standard]>=0.34 Provides-Extra: dev Requires-Dist: pytest-asyncio<1,>=0.23; extra == 'dev' Requires-Dist: pytest<9,>=8.0; extra == 'dev' Requires-Dist: ruff>=0.8; extra == 'dev' Description-Content-Type: text/markdown # a2o [![PyPI version](https://img.shields.io/pypi/v/ant2oai.svg)](https://pypi.org/project/ant2oai/) [![Python](https://img.shields.io/pypi/pyversions/ant2oai.svg)](https://pypi.org/project/ant2oai/) [![CI](https://github.com/WqyJh/a2o/actions/workflows/ci.yml/badge.svg)](https://github.com/WqyJh/a2o/actions/workflows/ci.yml) [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE) Lightweight **Anthropic-to-OpenAI** API proxy. Run [Claude Code](https://docs.anthropic.com/en/docs/claude-code) with any OpenAI-compatible backend. ## Features - Translates Anthropic `/v1/messages` requests to OpenAI `/v1/chat/completions` format - Streaming (SSE) and non-streaming support - Tool calling (function calling) with full round-trip conversion - Extended thinking / reasoning content - Image content (base64 and URL) - Multi-worker deployment with connection pooling - Minimal dependencies: FastAPI + httpx ## Installation ```bash pip install ant2oai ``` Or with [uv](https://docs.astral.sh/uv/): ```bash uv pip install ant2oai ``` ## Quick Start Start the proxy pointing to any OpenAI-compatible endpoint: ```bash a2o --upstream http://your-openai-endpoint/v1/chat/completions --model your-model ``` Then configure Claude Code to use the proxy: ```bash export ANTHROPIC_BASE_URL=http://127.0.0.1:3578 export ANTHROPIC_API_KEY=any-string # passed through to upstream claude ``` ## Usage ``` usage: a2o [-h] [--upstream UPSTREAM] [--model MODEL] [--host HOST] [--port PORT] [--timeout TIMEOUT] [--debug] [--workers WORKERS] [--max-connections MAX_CONNECTIONS] [--max-connections-per-host MAX_CONNECTIONS_PER_HOST] options: --upstream UPSTREAM OpenAI-compatible base URL --model MODEL Default model name override --host HOST Bind host (default: 127.0.0.1) --port PORT Bind port (default: 3578) --timeout TIMEOUT Request timeout in seconds (default: 300) --debug Enable debug logging --workers WORKERS Number of worker processes (default: 1) --max-connections N Max upstream connections (default: 1000) --max-connections-per-host N Max per-host connections (default: 500) ``` ### Production Deployment For high-throughput scenarios: ```bash a2o \ --upstream http://your-endpoint/v1/chat/completions \ --model your-model \ --host 0.0.0.0 \ --port 3578 \ --workers 4 \ --max-connections 2000 ``` ## How It Works ``` Claude Code ──► a2o proxy ──► OpenAI-compatible backend (Anthropic API) (converts) (OpenAI API) ``` 1. Claude Code sends requests in Anthropic format to the proxy 2. The proxy converts requests to OpenAI chat completion format 3. The upstream response is converted back to Anthropic format 4. Claude Code receives a native-looking Anthropic response ### Conversion Details | Anthropic | OpenAI | |-----------|--------| | `system` (string/blocks) | First `system` message | | `messages[].content` blocks | `messages[].content` parts | | `tool_use` content blocks | `tool_calls` on assistant messages | | `tool_result` content blocks | `tool` role messages | | `thinking` blocks | `reasoning_content` field | | `max_tokens` | `max_tokens` | | `stop_sequences` | `stop` | | Streaming SSE events | Streaming SSE chunks | ## Development ```bash # Clone and install git clone https://github.com/WqyJh/a2o.git cd a2o uv sync --all-extras # Run tests uv run pytest # Lint uv run ruff check . uv run ruff format --check . ``` ## License [MIT](LICENSE)