HRSSC / ELM Reference MCP Server

An MCP server exposing two independently queryable, fully offline vector databases for USPS/APWU labor-relations research:

• query_elm — the USPS Employee and Labor Relations Manual (ELM), chunked by its own section numbering (e.g. 511.43, 665.41).

• query_hrssc — the 2024-2029 APWU-HRSSC National Agreement, chunked by Article/Section, with source page numbers.

Both are semantic-search (embedding-based) retrieval tools. They surface the relevant text with exact citations; they do not interpret whether a provision applies to any specific situation — always verify the returned text against the actual document before relying on it.

What's in here

data/
  ELM_vectordb/      Chroma DB, collection "elm"
  HRSSC_vectordb/     Chroma DB, collection "hrssc_agreement"
src/
  server.py           MCP server (FastMCP), two tools
requirements.txt

Source material: ELM downloaded from the official USPS site (about.usps.com/manuals/elm/), March 2024 edition. HRSSC Agreement digitized from a personal printed copy (OCR'd, so expect occasional OCR noise in exact wording -- always confirm against the actual contract for anything consequential).

Related MCP server: Local Knowledge RAG MCP Server

Setup

pip install -r requirements.txt

Using with Claude Code / Claude Desktop

Add to your MCP config (e.g. claude_desktop_config.json or .claude/mcp.json):

{
  "mcpServers": {
    "hrssc-elm-reference": {
      "command": "python",
      "args": ["/absolute/path/to/hrssc-elm-mcp/src/server.py"]
    }
  }
}

Then ask Claude things like "check the ELM for reasonable accommodation standards" or "what does the HRSSC agreement say about non-career employees" and it will call query_elm / query_hrssc directly.

Using with ChatGPT / GPT-side tooling

ChatGPT doesn't speak MCP natively. Two practical options:

1. Local script, not a live connector: run src/server.py's underlying chromadb queries directly in a Python environment (e.g. a Code Interpreter session with the data/ folder uploaded) -- see the query_elm / query_hrssc functions in server.py for the exact query pattern to copy.

2. Wrap it as an HTTP API (not included here) and expose it as a Custom GPT Action, if you want live access from a hosted GPT rather than a one-off Code Interpreter session.

Standalone query script

For a quick terminal lookup without going through MCP at all:

python -c "
import sys
sys.path.insert(0, 'src')
from server import query_elm, query_hrssc
print(query_elm('your question here'))
print(query_hrssc('your question here'))
"

Caveats

• Retrieval only, not legal advice. Verify citations against the actual documents before relying on them for anything consequential.

• HRSSC Agreement text went through OCR on phone-photographed pages; spot-check exact wording on anything that matters.

• Neither DB covers the main APWU-USPS National Agreement (a separate document from the HRSSC-specific agreement) or USPS Handbook EL-307 (Reasonable Accommodation procedures) -- not included here.