chroma-mcp fails with Python 3.14: pydantic v1 incompatibility

[bkbThirteen]

Bug Report

Version: 10.3.1
Platform: macOS (darwin, aarch64)

Problem

chroma-mcp fails to start when launched via uvx on systems where Python 3.14 is the default. The MCP search tool returns MCP error -32000: Connection closed on every call.

Root cause

chromadb depends on pydantic v1 (pydantic.v1.BaseSettings), which is incompatible with Python 3.14:

```
chromadb/config.py:20: UserWarning: Core Pydantic V1 functionality isn't compatible with Python 3.14 or greater.
from pydantic.v1 import BaseSettings
Traceback (most recent call last):
...
File "chromadb/config.py", line 120, in
class Settings(BaseSettings):
...
File "pydantic/v1/main.py", line 221, in new
inferred = ModelField.infer(
```

Fix

In ChromaMcpManager.buildCommandArgs(), prepend --python 3.12 to the uvx args so chroma-mcp runs under a compatible Python version:

```ts
// Before
return [
'chroma-mcp',
'--client-type', 'persistent',
'--data-dir', DEFAULT_CHROMA_DATA_DIR
];

// After
return [
'--python', '3.12',
'chroma-mcp',
'--client-type', 'persistent',
'--data-dir', DEFAULT_CHROMA_DATA_DIR
];
```

The same fix likely applies to the remote mode args as well.

Workaround

Manually patch plugin/scripts/worker-service.cjs to add "--python","3.12" before "chroma-mcp" in the persistent client args, then restart the worker with bun plugin/scripts/worker-service.cjs restart.

[github-actions]

The GitHub issue highlights a bug in chroma-mcp (version 10.3.1) on macOS when Python 3.14 is the default, causing the tool to fail with the error MCP error -32000: Connection closed. The root cause is an incompatibility between Python 3.14 and pydantic v1, which chromadb depends on. Specifically, the use of pydantic.v1.BaseSettings in chromadb produces warnings and runtime errors. The proposed solution is to modify ChromaMcpManager.buildCommandArgs() to explicitly specify Python 3.12 when launching chroma-mcp using uvx, ensuring compatibility. A temporary workaround involves manually patching the script worker-service.cjs to include the --python 3.12 argument.

[thedotmack]

Closed via v10.4.0 release — fixed in PR #1214.