Add repository provider type for git-based MCP servers

[BillJr99]

Summary

This PR introduces a new repository provider type that allows mcpproxy to clone a git repository, run build commands, and spawn the resulting stdio MCP server. This enables support for MCP servers distributed only as source code (without npm/pip/binary distributions).

Key Changes

Frontend (frontend/app.py)

• Added REPOS_DIR import from config for repository workdir management
• New helper functions:
  • _get_repository_spec() — extracts the repository: block from YAML
  • _safe_provider_dirname() — normalizes provider names to safe directory names
  • _repository_workdir() — resolves on-disk workdir paths for repositories
• Updated _provider_to_structured() to handle repository specs alongside package/code types, populating repo_url, repo_ref, build_commands, and workdir fields
• Updated _structured_to_yaml() to serialize repository specs back to YAML with optional ref and workdir fields
• Enhanced _validate_provider() to validate repository specs (require repo_url and command, validate build_commands is a list)
• New /api/clone-and-build endpoint that:
  • Clones a git repo (or pulls if .git exists for idempotency)
  • Checks out an optional ref
  • Runs build commands inside the workdir
  • Returns workdir path or error details
• Updated /api/introspect to accept and forward a cwd parameter for running introspection inside a repository workdir
• Updated list_tools() to include is_repository flag in tool metadata
• Added UI components:
  • Repository type card in the wizard (alongside code and package)
  • Repository editor box with git URL, ref, build commands, and re-clone button
  • Wizard step for creating repository providers
  • CSS badge styling for repository providers (green)

Backend (server.py)

• Added REPOS_DIR import from config
• New helper functions:
  • repository_workdir() — resolves workdir path from spec, with fallback to REPOS_DIR/<provider_name>
  • materialize_repository() — idempotent clone/pull and build logic called on every server start
• Updated _make_process_handler() to accept and pass through cwd parameter to get_session()
• Updated register_provider() to:
  • Call materialize_repository() before registering tools
  • Pass repository workdir as cwd to process handlers
• Updated run_provider_setup() to call materialize_repository() before running requirements/setup_commands

Process Runner (process_runner.py)

• Updated ProcessSession to store and use cwd parameter when spawning subprocess
• Modified session registry key from command string to (command, cwd) tuple so different workdirs create separate sessions
• Updated get_session() to accept cwd parameter and use it for session keying
• Updated introspect() to accept and forward cwd parameter

Configuration (config.py)

• Added REPOS_DIR environment variable (default /app/repos) for repository clone base directory

Tests

• Added comprehensive test coverage in tests/test_frontend.py:
  • Repository provider round-trip (YAML ↔ structured JSON)
  • Repository validation (required fields, type checking)
  • /api/clone-and-build endpoint tests (clone, pull, ref checkout, error handling)
  • Introspect cwd parameter forwarding
  • UI element presence checks
• Added tests in tests/test_server.py:
  • repository_workdir() resolution logic
  • materialize_repository() clone/pull/build behavior
  • Repository provider registration with correct workdir
• Added new tests/test_process_runner.py for session cwd handling and registry keying

Documentation (README.md)

• Added repository provider overview and lifecycle documentation
• Documented wizard flow for creating repository providers
• Documented YAML structure with package: + `

https://claude.ai/code/session_01R2Vi6NE4wGxwv6rZ2HEXji