MCP Servers

MCP servers are reusable tool definitions that drwn can activate globally, attach to a project, bundle into a card source, and write into downstream agent tool configs.

Built-in definitions come from the harness registry. User definitions live under ~/.agents/drwn/mcp-servers. Card-declared definitions come from the locked cards consumed by the current project. Machine defaults live in ~/.agents/drwn/machine.json; project choices live in .agents/drwn/config.json.

Inspect active MCP state:

drwn mcp list
drwn mcp list --json
drwn doctor

drwn library add mcp ./context7.json --as context7
drwn library list mcp
drwn library defaults add mcp context7
drwn library defaults remove mcp context7

Attach MCP servers to a card source:

drwn card source add-mcp @your-handle/backend context7
drwn card source add-mcp @your-handle/backend context7 --from ./context7.json
drwn card source remove-mcp @your-handle/backend context7
drwn card source doctor @your-handle/backend

Card-local MCP definitions do not have to be reusable library entries. If a card ships a definition with optional: true, consuming the card does not activate that server immediately. drwn write reports the skipped optional MCP, and the project can opt in with:

drwn add mcp context7

Write the effective MCP config:

drwn mcp write --dry-run
drwn mcp write
drwn write --mcp-only