OuterSpace Apizr
Open-source capability compiler for Python codebases. Discover existing Python capabilities, plan explicit exposure, and expose selected functions through MCP or REST without rewriting business logic. Includes a local stdio MCP server with three read-only analysis and planning tools by default.
Documentation
OuterSpace Apizr
Connect selected Python functions to AI agents through MCP, or expose them as REST APIs.
Apizr is an open-source capability compiler: analyze existing Python code, choose which functions are public, generate their interfaces, and define how they execute. Your business logic stays in Python.
Quickstart: make your first MCP and REST calls · The full journey
Follow Install Apizr, then the Quickstart. See the release history for version-specific functionality, compatibility and verified publication. The journey is Python code → discover/select capabilities → expose as REST/MCP → optionally deliver as OCI.
Python 3.11–3.14 · GPL-3.0-or-later.
Choose your path
| Your goal | Start here |
|---|---|
| Expose Python functions as MCP tools or REST endpoints | Install → Quickstart |
| Analyze a project from an MCP client | Install the MCP profile → analysis server |
| Build and deliver a service | Install OCI or delivery → OCI and Attest |
| Initialize and diagnose a project (0.4.2) | Safe init, read-only doctor and shell completion |
| Validate/build in CI (0.4.2) | GitHub Action, GitLab component source and apizr ci |
The core handles supported static analysis and generation. Generated servers have their own runtime dependencies. Optional plugins live in separate environments; installation, activation and operator authorization are independent decisions.
Expose the functions you choose
Readiness reports whether the available code evidence supports an interface. An exposure policy names the functions you choose to make public. A bundle is the generated server, its contracts and the source needed by those functions. Being ready never makes a function public automatically.
| Connect through | Start with |
|---|---|
| MCP tools for agents and other clients | Generate MCP and make two calls |
| REST endpoints for applications | Generate REST and send two requests |
The generated MCP server calls your selected functions. The separate, Apizr analysis MCP server analyzes repositories and plans exposure; it does not execute their functions.
Choose execution boundaries
Analysis and generation do not execute the project. Starting a generated server and calling its functions does: use trusted source and dependencies. Direct mode runs functions inside the server. Governed mode uses an execution policy to choose a worker and its required limits: a fresh local process or an OCI container per call. Local workers do not isolate the host filesystem or network; containers are not an untrusted-code guarantee.
The direct Quickstart needs no Docker. Read the exposure guide for governed examples and the execution boundaries for their guarantees and limits.
Existing workflows and limits
Single-source inspect, generate rest/mcp and execute remain supported.
Apizr 0.4.2 also exports verified REST bundles to
Postman, Bruno and Insomnia collections,
with deterministic files and safe local regeneration.
The historical pipeline is a separate compatibility path. See the full journey for dependency, resource and exposure limits.
Watch the demo · Architecture · Development and checks · Report an issue · GPL-3.0-or-later