MCP Servers

pbi-agent can discover project-local MCP server definitions and expose their tools to the model as ordinary function tools. The runtime reads a single JSON file from the workspace root:

.agents/mcp.json

The file must contain a top-level servers object. Each entry can be either:

type: "stdio" with command, optional args, optional env, and optional cwd
type: "http" with url and optional headers

Example:

json

{
  "servers": {
    "github": {
      "type": "http",
      "url": "https://api.githubcopilot.com/mcp"
    },
    "playwright": {
      "command": "npx",
      "args": ["-y", "@microsoft/mcp-server-playwright"]
    }
  }
}

Discovered MCP tools are added to the model-facing tool list at startup. In the UI, you can inspect the discovered server list with /mcp, or from the CLI with pbi-agent --mcp.

TIP

Model-facing MCP tool names are namespaced per server, so a tool like say_hi from the echo server is exposed as echo__say_hi.

/reload does not reload MCP server configuration or already-started MCP tool catalogs. Restart the session after changing .agents/mcp.json or an MCP server's exposed tools.

MCP Servers ​

MCP Servers