feat: add experimental UV runtime support in manifest v0.4 #158
Conversation
domdomegg
left a comment
domdomegg
left a comment
There was a problem hiding this comment.
Sure, although I worry this means that mcpb is no longer self-contained i.e. it depends on other UV dependencies which may not be available to install etc. which breaks one of the guarantees that I think makes mcpb quite good.
| Four server types are supported: | ||
|
|
||
| - **`node`**: Node.js server with bundled dependencies | ||
| - **`python`**: Python server with bundled dependencies |
There was a problem hiding this comment.
should we have wording that raw python support may be removed and steer people to uv?
There was a problem hiding this comment.
For now, I'm going to mark uv as experimental in case this ends up being the wrong call (for whatever reason, e.g. mcp sdk no longer requires built dependencies?) and we want to backtrack to a bundled approach. Will update if/when we formalize!
@domdomegg the main issue we're running into is that python MCPBs include pydantic - which is a dependency of the MCP python sdk - and this requires the exact python version to exist on the user's machine that the mcpb was built with. There's essentially no good path for fully self-contained python MCPBs with that dependency in place Long shot but: is there any chance this package is an unnecessary dependency or might suitable replacements exist? It sounds like pydantic v1 had a pure-python mode but that version no longer seems to be supported |
joan-anthropic
force-pushed
the
joan/uv-runtime-support
branch
from
3163e3b to
342ad0f
Compare
Add UV as a new server type for Python extensions that use UV runtime
for dependency management instead of bundling dependencies.
Schema changes (v0.4):
- Add "uv" to server.type enum
- Make mcp_config optional (not needed for UV type)
- UV extensions rely on pyproject.toml for dependencies
Documentation:
- Add UV runtime section to MANIFEST.md explaining benefits and usage
- Update README.md to recommend UV runtime for Python
- Add complete hello-world-uv example
Benefits of UV runtime:
- Cross-platform support (Windows/macOS/Linux, Intel/ARM)
- Small bundle size (~100 KB vs 5-10 MB)
- Handles compiled dependencies portably
- No user Python installation required
Example manifest:
{
"manifest_version": "0.4",
"server": {
"type": "uv",
"entry_point": "src/server.py"
}
}
Co-authored-by: Joan <joan@anthropic.com>
joan-anthropic
force-pushed
the
joan/uv-runtime-support
branch
from
342ad0f to
d90365e
Compare
joan-anthropic
changed the title
🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
Add UV as a new server type for Python extensions that use UV runtime for dependency management instead of bundling dependencies.
Schema changes (v0.4):
Motivation and Context
How Has This Been Tested?
Breaking Changes
Types of changes
Checklist
Additional context