Pieces MCP

Pieces MCP Skill for ArgentOS

Connect ArgentOS to Pieces long-term memory via MCP. Pieces captures ambient context (browser, clipboard, meetings, code) across devices. This skill teaches you how to wire it into ArgentOS so you can query that memory and create durable summaries.

When to Use This Skill

Trigger when:

• The human mentions Pieces, PiecesOS, or long-term memory
• They want cross-device memory: "What did I work on today?"
• They say "Hook up to my Pieces" or "Ask Pieces"
• You see an HTTPS tunnel URL for a Pieces MCP server

Architecture

Three components:

1. PiecesOS MCP server — runs on the human's machine with Long-Term Memory (LTM) enabled. Exposed via HTTPS tunnel.
2. ArgentOS gateway — this machine. Connects to the Pieces MCP server via gateway.mcp.servers config.
3. Bridge: mcp-remote — npm package that connects to the remote /mcp endpoint and exposes it locally as a stdio MCP server.

Important: This integration is MCP-only. Always use /mcp, never /sse.

Setup Guide

Step 1: Confirm PiecesOS Is Running

Ask the human to confirm:

"Make sure PiecesOS is installed and running on your machine (or remote machine), and that Long-Term Memory (LTM) is enabled in the Pieces Desktop App."

Step 2: Get the Tunnel URL

The human needs to expose PiecesOS's MCP server via HTTPS:

For ngrok:

"On the machine running PiecesOS, run:

ngrok http 39300

Paste the HTTPS forwarding URL here (e.g., https://abc123.ngrok-free.dev)."

For custom tunnels: Any HTTPS URL that forwards to localhost:39300 works.

Step 3: Verify the MCP Endpoint

Construct the MCP URL:

MCP_URL = <tunnel_url>/model_context_protocol/2025-03-26/mcp

Quick sanity check:

curl -i "<MCP_URL>"

Expected: HTTP 400 with "mcp-session-id header or sessionId query parameter is required". This means the server is alive and ready.

If you get 404, 502, or timeout — the tunnel is down. Ask the human to check PiecesOS and the tunnel.

Step 4: Configure ArgentOS

Add the Pieces MCP server to ~/.argentos/argent.json under gateway.mcp.servers:

{
  "gateway": {
    "mcp": {
      "servers": {
        "pieces": {
          "command": "mcp-remote",
          "args": ["<MCP_URL>"]
        }
      }
    }
  }
}

Example with ngrok:

{
  "gateway": {
    "mcp": {
      "servers": {
        "pieces": {
          "command": "mcp-remote",
          "args": ["https://abc123.ngrok-free.dev/model_context_protocol/2025-03-26/mcp"]
        }
      }
    }
  }
}

Step 5: Install mcp-remote

npm install -g mcp-remote@0.1.38

Step 6: Restart the Gateway

argent gateway restart

The Pieces MCP tools are now available to all agent sessions.

Available Tools

Once connected, three Pieces tools become available:

ask_pieces_ltm

Query long-term memory with a natural language question:

{
  "name": "ask_pieces_ltm",
  "arguments": {
    "question": "What did I work on today?",
    "chat_llm": "gpt-4"
  }
}

Returns summaries[] and events[] as structured JSON. Parse this and synthesize a natural language answer for the human.

Use for:

• "What did I work on today / this week?"
• "What did we discuss in the standup?"
• "What debugging steps did I try last time?"

When you answer, attribute it:

"According to your Pieces long-term memory, ..."

create_pieces_memory

Write a durable memory:

{
  "name": "create_pieces_memory",
  "arguments": {
    "summary_description": "Profile: Jason — MSP Owner",
    "summary": "# Profile: Jason\n\n## Role\nMSP owner, AI developer\n\n## Current Focus\nArgentOS development",
    "project": "ArgentOS"
  }
}

Use for:

• Human profile (name, role, preferences)
• Decision summaries
• Debugging recaps
• Project milestones

Full-Text Search Tools

Search tools (names vary by PiecesOS version) provide keyword-based search across all captured context.

Troubleshooting

MCP URL returns 404/502/timeout

• Confirm PiecesOS is running on the remote machine
• Confirm the tunnel is active (ngrok may have restarted)
• Ask the human for a fresh tunnel URL

Tools not appearing after gateway restart

1. Check ~/.argentos/argent.json has the gateway.mcp.servers.pieces entry
2. Verify mcp-remote is installed: mcp-remote --help
3. Test the MCP URL directly with curl (Step 3)
4. Check gateway logs: grep pieces /tmp/argent/argent-*.log

ask_pieces_ltm times out or gives vague answers

Narrow the query:

• Add time: "What did I work on this morning?"
• Add topic: "What have I done on the website project?"
• Add context: "What debugging steps did I try for the login bug?"

Raw JSON responses

This is normal. Pieces returns structured JSON with summaries[] and events[]. You (the agent) parse it and synthesize a natural language answer. The raw JSON is not an error.

Direct Testing (Debugging Only)

If MCPorter/mcp-remote isn't working, test the MCP server directly:

Create init.json:

{
  "jsonrpc": "2.0",
  "method": "initialize",
  "params": {
    "protocolVersion": "0.1.0",
    "capabilities": {},
    "clientInfo": { "name": "argentos-agent", "version": "1.0" }
  },
  "id": "1"
}

curl -i -X POST "<MCP_URL>" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "mcp-session-id: init-001" \
  --data-binary @init.json

Extract the mcp-session-id from the response headers (13-digit timestamp like 1774202062499). Use that for all subsequent requests.

Common mistakes: Use --data-binary @file.json (not inline -d), use string IDs ("id": "1" not "id": 1), always include both Content-Type and Accept headers.