Myelin SDK

Procedural memory for AI agents. Agents that have done a task 100 times shouldn't fumble on attempt 101.

Claude Code

Zero-code integration via PostToolUse hooks.

1. Install the SDK

uv tool install myelin-sdk

2. Add the MCP server

claude mcp add --scope project --transport http myelin https://myelin.fly.dev/mcp \
  -H "Authorization: Bearer YOUR_API_KEY"

3. Add the PostToolUse hook

Add this to .claude/settings.json:

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "myelin-capture"
          }
        ]
      }
    ],
    "PostToolUseFailure": [
      {
        "matcher": "",
        "hooks": [
          {
            "type": "command",
            "command": "myelin-capture"
          }
        ]
      }
    ]
  }
}

Tip: If myelin-capture is not on your PATH, use python -m myelin_sdk.claude_code as the command instead.

4. Update .gitignore

Add .mcp.json to your .gitignore (it contains your API key).

The hook captures every tool call automatically. Use search to find workflows, record to begin a session, and finish to end it.

Python SDK / LangChain

Explicit integration for LangChain and LangGraph agents.

pip install myelin-sdk[langchain]

from myelin_sdk import MyelinSession

async with MyelinSession.create("handle support ticket", api_key="my_...") as session:
    handler = session.langchain_handler()

    # Pass handler to your LangChain agent
    result = await agent.ainvoke(
        {"messages": [{"role": "user", "content": "..."}]},
        config={"callbacks": [handler]},
    )
# session.finish() called automatically on exit

Adding an Integration

The integrations/langchain/ directory is the template for new integrations. To add support for another framework (e.g., CrewAI, AutoGen):

1. Create src/myelin_sdk/integrations/<framework>/
2. Add __init__.py and a handler module
3. Use MyelinClient.capture() to record tool calls
4. Add an optional dependency group in pyproject.toml
5. Add a convenience method on MyelinSession

See integrations/langchain/handler.py for a complete reference implementation.

Syncing Local Procedures

Sync markdown procedure files from your repo to Myelin:

pip install myelin-sdk

# Sync all procedures from default directory (.claude/procedures/*.md)
myelin-sync

# Sync from a custom directory
myelin-sync --dir ./runbooks

# Sync specific files
myelin-sync deploy.md hotfix.md

Requires MYELIN_API_KEY, MYELIN_BASE_URL, and MYELIN_PROJECT_ID environment variables (or reads from .mcp.json).

Sync is idempotent — running twice with unchanged files produces no updates. Deleting a local file does not remove the server copy.