Bug: console.log in embeddings.ts breaks MCP JSON protocol

[Tapiocapioca]

Description

The embeddings.ts file uses console.log() which outputs to stdout. In the MCP (Model Context Protocol) context, stdout is reserved for JSON-RPC communication. Any non-JSON output to stdout corrupts the protocol and causes connection errors.

Error observed in Claude Code debug logs

MCP server "plugin:episodic-memory:episodic-memory": Connection error: Unexpected token 'L', "Loading em"... is not valid JSON
MCP server "plugin:episodic-memory:episodic-memory": Connection error: Unexpected token 'E', "Embedding "... is not valid JSON

Root cause

1. src/embeddings.ts lines 7 and 12 use console.log() instead of console.error()
2. The @xenova/transformers library outputs progress messages to stdout by default

Suggested fix

In src/embeddings.ts:

import { pipeline, Pipeline, FeatureExtractionPipeline, env } from '@xenova/transformers';

// Disable progress callbacks to prevent stdout pollution in MCP context
env.allowLocalModels = true;
env.useBrowserCache = false;

let embeddingPipeline: FeatureExtractionPipeline | null = null;

export async function initEmbeddings(): Promise<void> {
  if (!embeddingPipeline) {
    console.error('Loading embedding model (first run may take time)...');  // Changed from console.log
    embeddingPipeline = await pipeline(
      'feature-extraction',
      'Xenova/all-MiniLM-L6-v2',
      { progress_callback: null }  // Disable progress output to stdout
    );
    console.error('Embedding model loaded');  // Changed from console.log
  }
}

Changes needed

1. Change console.log → console.error for all status messages (stdout is reserved for MCP JSON)
2. Add { progress_callback: null } to the pipeline options to disable @xenova/transformers progress output
3. Import env from @xenova/transformers and configure it to prevent additional stdout output

Environment

• episodic-memory version: 1.0.15
• Claude Code version: 2.1.2
• OS: Windows 11

Workaround

I've manually patched dist/embeddings.js with the fix above and it resolves the issue.