Overview
OGX is an open-source agentic API server for building AI applications. It is a drop-in replacement for the OpenAI API that runs on a laptop, in a datacenter or in the cloud, so any OpenAI-compatible client or agent framework can talk to it unchanged. The project is the continuation of Meta's Llama Stack: the repository states plainly that Llama Stack is now OGX, and that the mission changed with the name — model-agnostic, multi-SDK, production-grade.
The server covers the standard surface — `/v1/chat/completions`, `/v1/completions` and `/v1/embeddings` — plus the Responses API for server-side agentic orchestration, where tool calling, MCP server integration and built-in file search (RAG) happen inside a single API call. Around that sit `/v1/vector_stores` and `/v1/files` for managed document storage and search, `/v1/batches` for offline batch work, and `/v1alpha/skills` for versioned skill bundles — zip archives with a SKILL.md manifest that agents can invoke. The Responses implementation passes the Open Responses conformance suite.
Multi-SDK support is the other half of the pitch: alongside the OpenAI API, OGX natively serves the Anthropic Messages API at `/v1/messages` and the Google GenAI interactions API at `/v1alpha/interactions`. A pluggable provider architecture keeps the API stable while the backend changes — develop against Ollama locally, deploy on vLLM in production, or point at a managed service. Official client SDKs exist for Python and TypeScript, with an OpenAPI-generated alternative for teams whose tooling needs it.
What it does
- OpenAI-compatible chat completions, completions and embeddings endpoints, usable from any OpenAI client
- Responses API with server-side tool calling, MCP server integration and built-in file search, verified against the Open Responses conformance suite
- Vector stores and files endpoints for managed document storage and retrieval
- Batches endpoint for offline, high-volume processing
- Skills — versioned zip bundles with a SKILL.md manifest that agents can call at /v1alpha/skills
- Native Anthropic Messages and Google GenAI interactions endpoints alongside the OpenAI surface
- Pluggable providers so the same API runs on Ollama locally and vLLM or a managed service in production
- Official Python and TypeScript client SDKs (ogx_client), plus an OpenAPI-generated alternative
Getting started
OGX installs as a Python package and starts a server that auto-detects providers from your environment.
Install the server
# One-line install
curl -LsSf https://github.com/ogx-ai/ogx/raw/main/scripts/install.sh | bash
# Or via uv
uv pip install ogxStart it
`ogx go` reads the environment to work out which providers are available.
uv run ogx goPoint an OpenAI client at it
The server listens on port 8321 by default; the API key is ignored for local use.
from openai import OpenAI
client = OpenAI(base_url="http://localhost:8321/v1", api_key="fake")
response = client.chat.completions.create(
model="llama-3.3-70b",
messages=[{"role": "user", "content": "Hello"}],
)Or use the official client SDK
Published on PyPI as ogx_client and on npm as ogx-client.
pip install ogx_client
# or
npm install ogx-clientCommands and code are distilled from the project's own documentation — always check the official repo for the latest.
When to use it
- Put one OpenAI-compatible endpoint in front of several model providers so application code never changes when the model does
- Serve the Responses API self-hosted, with tool calls, MCP servers and file search resolved server-side
- Develop against Ollama on a laptop and deploy the same stack on vLLM without touching the client
- Expose the OpenAI, Anthropic and Google GenAI SDK surfaces from a single server for a mixed-SDK codebase
How OGX compares
OGX alongside other open-source app frameworks tools AI/TLDR tracks, ranked by GitHub stars.
| Tool | Stars | What it does |
|---|---|---|
| LangChain | ★ 147k | A widely used Python and JavaScript framework for building LLM applications by composing models, prompts, tools, retrievers, and memory into chains. |
| LlamaIndex | ★ 52.2k | A data framework for connecting language models to your own documents and data sources, with built-in agent and retrieval (RAG) tooling. |
| Haystack | ★ 26.5k | An orchestration framework from deepset for building modular LLM pipelines and agents for search, RAG, and question answering. |
| Jina | ★ 21.9k | Jina-serve is a Python framework for building, scaling, and deploying AI services and multi-step pipelines that communicate over gRPC, HTTP, and WebSockets. |
| LLM | ★ 12.5k | Simon Willison's plugin-extensible CLI and Python library for prompting remote and local models, logging every prompt and response to SQLite, and generating embeddings. |
| Prompt Flow | ★ 11.2k | Microsoft's toolkit for building LLM apps as executable flows that link prompts, Python code, and tools, with tracing, batch evaluation, and deployment. |
| Rig | ★ 8.7k | A Rust library for building LLM-powered applications, giving one unified interface over 20+ model providers and 10+ vector stores plus an agent runtime with streaming, tools, and OpenTelemetry GenAI tracing. |
| OGX | ★ 8.4k | The project formerly known as Llama Stack — an OpenAI-compatible agentic API server you run anywhere, with pluggable model providers |