Retire mcp-loader.ts in favour of pi's built-in MCP support
pi has had MCP as a built-in extension (builtin:mcp) since 0.99.0. It reads ~/.pi/agent/mcp.json and adds `pi mcp add|list|login`, a /mcp manager, OAuth, per-tool exposure and resources. An extension that registers /mcp REPLACES the built-in, so with mcp-loader installed pi never read mcp.json and printed "registers command /mcp, so built-in extension mcp was not loaded" on every start. Measured on pi 1.1.0 (pi-devbox v1.11.0, tor-ms22) before removing it: - time to the (auto) footer in a real pty, 7 interleaved runs each: -ne 0.276 s | -ne -e mcp-loader.ts 0.283 s | -ne -e builtin:mcp 0.272 s - with no servers, the same prompt costs 79 input + 7680 cached tokens with the loader, the built-in, or neither - a stdio server (server-everything) connected via `pi mcp list` in 3 s, and its echo tool ran end to end from `pi -p` with direct exposure - no device in the fleet had an `mcp` block, so nothing needs migrating install.sh now prunes links into this repo whose target is gone (.ts and .ts.off), so the stale mcp-loader.ts link on a preserved pi-devbox volume is removed on the first boot of an image without the file. It also warns once if settings.json still carries an `mcp` block. Tested two-sided in a temp HOME: the new script removes the repo link and a stale .ts.off, and keeps a foreign dangling link and a real file. The old script leaves the dangling link. Re-runs are idempotent, and there is no warning without an mcp block. mempalace.ts (mempalace-toolkit) is unaffected: it registers mempalace_* tools itself. Its vendored RemoteMcpClient loses its sync partner; that is handled in mempalace-toolkit.
This commit is contained in:
@@ -1,842 +0,0 @@
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/**
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* MCP Loader Extension
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*
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* Reads an `mcp` block from pi's settings.json (same shape as opencode and
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* Claude Desktop) and connects to each declared server, exposing all of
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* their tools to pi as native tools.
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*
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* Settings.json shape:
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*
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* {
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* "mcp": {
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* "searxng": {
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* "type": "local",
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* "command": ["uvx", "mcp-searxng"],
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* "env": { "SEARXNG_URL": "https://searxng.your-host.lan" }
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* },
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* "gitea": {
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* "type": "local",
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* "command": ["gitea-mcp", "-t", "stdio"],
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* "enabled": false,
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* "env": { "GITEA_ACCESS_TOKEN": "...", "GITEA_HOST": "..." }
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* },
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* "context7": {
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* "type": "remote",
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* "url": "https://mcp.context7.com/mcp",
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* "headers": { "Authorization": "Bearer …" }
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* }
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* }
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* }
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*
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* Per-server keys:
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* type "local" (stdio subprocess) | "remote" (streamable-http)
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* command argv array — first element is the executable, rest are args.
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* For local servers only.
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* url remote MCP endpoint URL. For remote servers only.
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* headers optional object of HTTP headers to send with every request to
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* a remote server (e.g. Authorization, X-API-Key). Remote only.
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* enabled default true. Set false to disable a server without
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* removing it from settings.json.
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* env optional object of environment variables to inject into
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* the spawned subprocess. Inherits parent env first, then
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* overlays these keys. Local only.
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*
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* Tool naming
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*
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* Each MCP tool is registered with pi as `<server-name>_<tool-name>` to
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* avoid collisions across servers. If the tool name already begins with
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* `<server-name>_` (e.g. mempalace's tools are `mempalace_search` etc.)
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* the prefix is not duplicated.
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*
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* Lifecycle
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*
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* • Servers are connected at extension load time (pi startup or /reload).
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* • Each server's `tools/list` is awaited before pi finishes registering.
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* • Local subprocess stderr is silenced unless PI_MCP_LOADER_DEBUG=1.
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* • Local subprocesses receive SIGTERM at session_shutdown; remote
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* servers receive an MCP DELETE if a session id was issued.
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* • A server that fails to start (binary missing, init handshake error,
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* remote 4xx/5xx) logs a single line to stderr and is skipped. Other
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* servers continue. Pi keeps working without that server's tools.
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*
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* Transports
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*
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* local — stdio JSON-RPC subprocess (mcp-searxng, gitea-mcp, …).
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* remote — streamable-HTTP per MCP spec 2025-03-26: POST JSON-RPC, server
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* replies either application/json or text/event-stream. Optional
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* Mcp-Session-Id header round-tripped if the server issues one.
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* No GET-stream subscription (we don't consume server-initiated
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* notifications).
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*
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* Limitations
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*
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* • No stdio reconnect: if a stdio subprocess dies mid-session, its tools
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* become unavailable until pi is reloaded. The mempalace.ts extension
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* has the same limitation today.
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* • Remote sessions self-heal on 404: if a streamable-HTTP server
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* forgets our session id (e.g. server restart), the next request gets
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* HTTP 404; the client transparently re-initializes and retries the
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* request once. Persistent 404s after refresh surface as errors.
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* • No OAuth flow: remote servers requiring OAuth must be accessed with
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* a pre-issued bearer token via `headers`.
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*
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* Coexistence with mempalace.ts
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*
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* The mempalace.ts extension already spawns mempalace-mcp directly with
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* bespoke handling (agent identity injection from $MEMPALACE_AGENT_NAME,
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* wake-up context). This loader does NOT touch mempalace — leave the
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* bespoke extension in place. If you also list mempalace under the `mcp`
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* block in settings.json the loader will register a parallel set of
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* tools, which is harmless but redundant. Don't.
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*
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* Slash command
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*
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* `/mcp` lists configured MCP servers with their runtime status
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* (running / failed / disabled / invalid) and lets
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* you toggle the `enabled` flag in settings.json. Same UX as `/ext`:
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* space stages, enter applies + reloads, esc cancels.
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*/
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import { type ChildProcessWithoutNullStreams, spawn } from "node:child_process";
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import * as fs from "node:fs";
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import * as os from "node:os";
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import * as path from "node:path";
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import {
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type ExtensionAPI,
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getSettingsListTheme,
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} from "@earendil-works/pi-coding-agent";
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import {
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Container,
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Key,
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matchesKey,
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type SettingItem,
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SettingsList,
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} from "@earendil-works/pi-tui";
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import { Type } from "typebox";
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// ── MCP types ────────────────────────────────────────────────────────────────
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type McpTool = {
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name: string;
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description?: string;
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inputSchema?: Record<string, unknown>;
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};
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type LocalServerConfig = {
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type?: "local";
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command: string[];
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env?: Record<string, string>;
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enabled?: boolean;
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};
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type RemoteServerConfig = {
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type: "remote";
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url: string;
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headers?: Record<string, string>;
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enabled?: boolean;
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};
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type ServerConfig = LocalServerConfig | RemoteServerConfig;
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const SETTINGS_PATH = path.join(os.homedir(), ".pi", "agent", "settings.json");
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const DEBUG = process.env.PI_MCP_LOADER_DEBUG === "1";
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// MCP protocol version we advertise. Servers we've tested:
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// - searxng (mcp-searxng) accepts both 2024-11-05 and 2025-11-25
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// - context7 accepts both
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// - mempalace bridge: not touched by this loader
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// Bump as the spec evolves; both stdio and remote clients use this.
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const MCP_PROTOCOL_VERSION = "2025-11-25";
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function dlog(msg: string) {
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if (DEBUG) process.stderr.write(`[mcp-loader] ${msg}\n`);
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}
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function warn(msg: string) {
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process.stderr.write(`[mcp-loader] ${msg}\n`);
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}
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// ── Settings.json reader ─────────────────────────────────────────────────────
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function readMcpServers(): Record<string, ServerConfig> {
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if (!fs.existsSync(SETTINGS_PATH)) {
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dlog(`no settings.json at ${SETTINGS_PATH}`);
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return {};
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}
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let raw: string;
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try {
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raw = fs.readFileSync(SETTINGS_PATH, "utf8");
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} catch (err) {
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warn(`could not read ${SETTINGS_PATH}: ${(err as Error).message}`);
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return {};
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}
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let parsed: any;
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try {
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parsed = JSON.parse(raw);
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} catch (err) {
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warn(`settings.json parse error: ${(err as Error).message}`);
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return {};
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}
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const block = parsed?.mcp;
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if (!block || typeof block !== "object") {
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dlog("no `mcp` block in settings.json");
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return {};
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}
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return block as Record<string, ServerConfig>;
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}
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// ── Stdio MCP client ─────────────────────────────────────────────────────────
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interface IMcpClient {
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readonly serverName: string;
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tools: McpTool[];
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start(): Promise<void>;
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callTool(name: string, args: Record<string, unknown>): Promise<any>;
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stop(): void | Promise<void>;
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}
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class StdioMcpClient implements IMcpClient {
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private proc: ChildProcessWithoutNullStreams | null = null;
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private nextId = 1;
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private pending = new Map<number, { resolve: (v: any) => void; reject: (e: Error) => void }>();
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private stdoutBuf = "";
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public readonly serverName: string;
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private command: string;
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private args: string[];
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private env: Record<string, string> | undefined;
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public tools: McpTool[] = [];
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constructor(serverName: string, command: string, args: string[], env?: Record<string, string>) {
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this.serverName = serverName;
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this.command = command;
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this.args = args;
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this.env = env;
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}
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async start(): Promise<void> {
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const childEnv = { ...process.env, ...(this.env ?? {}) };
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this.proc = spawn(this.command, this.args, { stdio: ["pipe", "pipe", "pipe"], env: childEnv });
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this.proc.on("error", (err) => this.failAll(err));
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this.proc.on("exit", (code, signal) => {
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this.failAll(new Error(`${this.serverName}: subprocess exited (code=${code}, signal=${signal})`));
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});
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this.proc.stdout.setEncoding("utf8");
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this.proc.stdout.on("data", (chunk: string) => this.onStdout(chunk));
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this.proc.stderr.setEncoding("utf8");
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if (DEBUG) {
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this.proc.stderr.on("data", (chunk: string) => {
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process.stderr.write(`[${this.serverName} stderr] ${chunk}`);
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});
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} else {
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this.proc.stderr.resume(); // drain without logging
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}
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// MCP initialize handshake
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await this.request("initialize", {
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protocolVersion: MCP_PROTOCOL_VERSION,
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capabilities: {},
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clientInfo: { name: "pi-mcp-loader", version: "0.2.0" },
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});
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this.notify("notifications/initialized", {});
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const listed = await this.request("tools/list", {});
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this.tools = (listed?.tools as McpTool[]) ?? [];
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}
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private onStdout(chunk: string) {
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this.stdoutBuf += chunk;
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let nl: number;
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while ((nl = this.stdoutBuf.indexOf("\n")) !== -1) {
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const line = this.stdoutBuf.slice(0, nl).trim();
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this.stdoutBuf = this.stdoutBuf.slice(nl + 1);
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if (!line) continue;
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let msg: any;
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try {
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msg = JSON.parse(line);
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} catch {
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continue;
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}
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if (typeof msg.id === "number" && this.pending.has(msg.id)) {
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const { resolve, reject } = this.pending.get(msg.id)!;
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this.pending.delete(msg.id);
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if (msg.error) reject(new Error(msg.error.message ?? "MCP error"));
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else resolve(msg.result);
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}
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// notifications (no id) ignored.
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}
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}
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private failAll(err: Error) {
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for (const { reject } of this.pending.values()) reject(err);
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this.pending.clear();
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}
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private write(obj: unknown) {
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if (!this.proc) throw new Error(`${this.serverName}: not started`);
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this.proc.stdin.write(`${JSON.stringify(obj)}\n`);
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}
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private notify(method: string, params: unknown) {
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this.write({ jsonrpc: "2.0", method, params });
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}
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request(method: string, params: unknown): Promise<any> {
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const id = this.nextId++;
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return new Promise((resolve, reject) => {
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this.pending.set(id, { resolve, reject });
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this.write({ jsonrpc: "2.0", id, method, params });
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});
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}
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async callTool(name: string, args: Record<string, unknown>): Promise<any> {
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return this.request("tools/call", { name, arguments: args });
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}
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stop() {
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if (this.proc) {
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try {
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this.proc.kill("SIGTERM");
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} catch {}
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this.proc = null;
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}
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}
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}
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// ── Streamable-HTTP MCP client (remote) ──────────────────────────────────────
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//
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// MCP-STREAMABLE-HTTP-CLIENT-SYNC: v1
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// Canonical copy. This class is VENDORED into
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// mempalace-toolkit/extensions/pi/mempalace.ts (adapted: pinned protocolVersion,
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// AbortController timeouts, alive/ensureAlive). When you change the
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// streamable-HTTP protocol handling here, bump the SYNC token in BOTH files.
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// mempalace-toolkit/scripts/check-mcp-client-sync.sh enforces the match.
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//
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// Per MCP spec 2025-03-26: a single endpoint URL accepts POST with a
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// JSON-RPC body. The server responds either with application/json (a
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// single response) or text/event-stream (an SSE stream containing the
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// response, possibly preceded by notifications, terminated by stream
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// close). We do NOT open a separate GET subscription stream — we don't
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// consume server-initiated notifications today.
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//
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// Session id: if the server returns an Mcp-Session-Id header on
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// initialize, we round-trip it on every subsequent request and DELETE
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// it on stop().
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class RemoteMcpClient implements IMcpClient {
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public readonly serverName: string;
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private url: string;
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private extraHeaders: Record<string, string>;
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private sessionId: string | null = null;
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private nextId = 1;
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public tools: McpTool[] = [];
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constructor(serverName: string, url: string, headers?: Record<string, string>) {
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this.serverName = serverName;
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this.url = url;
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this.extraHeaders = headers ?? {};
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}
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async start(): Promise<void> {
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await this.request("initialize", {
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protocolVersion: MCP_PROTOCOL_VERSION,
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capabilities: {},
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clientInfo: { name: "pi-mcp-loader", version: "0.2.0" },
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});
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await this.notify("notifications/initialized", {});
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const listed = await this.request("tools/list", {});
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this.tools = (listed?.tools as McpTool[]) ?? [];
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}
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async callTool(name: string, args: Record<string, unknown>): Promise<any> {
|
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return this.request("tools/call", { name, arguments: args });
|
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}
|
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|
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async stop(): Promise<void> {
|
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if (!this.sessionId) return;
|
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try {
|
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await fetch(this.url, { method: "DELETE", headers: this.buildHeaders() });
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} catch {}
|
||||
}
|
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private buildHeaders(): Record<string, string> {
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const h: Record<string, string> = {
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"Content-Type": "application/json",
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Accept: "application/json, text/event-stream",
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"MCP-Protocol-Version": MCP_PROTOCOL_VERSION,
|
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...this.extraHeaders,
|
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};
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if (this.sessionId) h["Mcp-Session-Id"] = this.sessionId;
|
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return h;
|
||||
}
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||||
|
||||
/**
|
||||
* Re-establish a session after the server returned 404 to a request that
|
||||
* carried our `Mcp-Session-Id`. Per spec 2025-11-25, the client MUST start
|
||||
* a new session by sending a fresh InitializeRequest without a session id.
|
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*
|
||||
* Caller must clear `this.sessionId` BEFORE invoking this so the new
|
||||
* initialize POST goes out without the stale id.
|
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*/
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||||
private async reinitialize(): Promise<void> {
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dlog(`${this.serverName}: session lost (404) — reinitializing`);
|
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await this.request("initialize", {
|
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protocolVersion: MCP_PROTOCOL_VERSION,
|
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capabilities: {},
|
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clientInfo: { name: "pi-mcp-loader", version: "0.2.0" },
|
||||
}, /*allowReinitOn404=*/ false);
|
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await this.notify("notifications/initialized", {});
|
||||
}
|
||||
|
||||
private async request(method: string, params: unknown, allowReinitOn404 = true): Promise<any> {
|
||||
const id = this.nextId++;
|
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const body = JSON.stringify({ jsonrpc: "2.0", id, method, params });
|
||||
const sessionAtStart = this.sessionId;
|
||||
let res: Response;
|
||||
try {
|
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res = await fetch(this.url, { method: "POST", headers: this.buildHeaders(), body });
|
||||
} catch (err) {
|
||||
throw new Error(`${this.serverName}: fetch failed on ${method}: ${(err as Error).message}`);
|
||||
}
|
||||
|
||||
const sid = res.headers.get("Mcp-Session-Id") ?? res.headers.get("mcp-session-id");
|
||||
if (sid) this.sessionId = sid;
|
||||
|
||||
// 404 + we sent a session id → server forgot us. Drop our id, re-init,
|
||||
// retry once. `allowReinitOn404=false` is passed by the recovery path to
|
||||
// prevent infinite recursion if the server is permanently broken.
|
||||
if (res.status === 404 && sessionAtStart && allowReinitOn404) {
|
||||
try { await res.arrayBuffer(); } catch {}
|
||||
this.sessionId = null;
|
||||
await this.reinitialize();
|
||||
return this.request(method, params, /*allowReinitOn404=*/ false);
|
||||
}
|
||||
|
||||
if (!res.ok) {
|
||||
let detail = "";
|
||||
try { detail = (await res.text()).slice(0, 200); } catch {}
|
||||
throw new Error(`${this.serverName}: HTTP ${res.status} on ${method}${detail ? `: ${detail}` : ""}`);
|
||||
}
|
||||
|
||||
const ct = (res.headers.get("content-type") ?? "").toLowerCase();
|
||||
if (ct.includes("text/event-stream")) {
|
||||
return await this.readSseForResponse(res, id);
|
||||
}
|
||||
if (ct.includes("application/json")) {
|
||||
const json: any = await res.json();
|
||||
if (json.error) throw new Error(json.error.message ?? "MCP error");
|
||||
return json.result;
|
||||
}
|
||||
if (res.status === 202) return undefined;
|
||||
throw new Error(`${this.serverName}: unexpected content-type "${ct}" on ${method}`);
|
||||
}
|
||||
|
||||
private async notify(method: string, params: unknown): Promise<void> {
|
||||
const body = JSON.stringify({ jsonrpc: "2.0", method, params });
|
||||
let res: Response;
|
||||
try {
|
||||
res = await fetch(this.url, { method: "POST", headers: this.buildHeaders(), body });
|
||||
} catch (err) {
|
||||
throw new Error(`${this.serverName}: fetch failed on notify ${method}: ${(err as Error).message}`);
|
||||
}
|
||||
try { await res.arrayBuffer(); } catch {}
|
||||
if (!res.ok && res.status !== 202) {
|
||||
throw new Error(`${this.serverName}: HTTP ${res.status} on notify ${method}`);
|
||||
}
|
||||
}
|
||||
|
||||
private async readSseForResponse(res: Response, expectedId: number): Promise<any> {
|
||||
if (!res.body) throw new Error(`${this.serverName}: SSE response had no body`);
|
||||
const reader = res.body.getReader();
|
||||
const decoder = new TextDecoder();
|
||||
let buf = "";
|
||||
let dataLines: string[] = [];
|
||||
|
||||
const tryDispatch = (): { matched: boolean; result?: any } => {
|
||||
if (dataLines.length === 0) return { matched: false };
|
||||
const data = dataLines.join("\n");
|
||||
dataLines = [];
|
||||
let msg: any;
|
||||
try {
|
||||
msg = JSON.parse(data);
|
||||
} catch {
|
||||
return { matched: false };
|
||||
}
|
||||
if (typeof msg.id === "number" && msg.id === expectedId) {
|
||||
if (msg.error) throw new Error(msg.error.message ?? "MCP error");
|
||||
return { matched: true, result: msg.result };
|
||||
}
|
||||
return { matched: false };
|
||||
};
|
||||
|
||||
try {
|
||||
while (true) {
|
||||
const { done, value } = await reader.read();
|
||||
if (done) break;
|
||||
buf += decoder.decode(value, { stream: true });
|
||||
let nl: number;
|
||||
while ((nl = buf.indexOf("\n")) !== -1) {
|
||||
const rawLine = buf.slice(0, nl);
|
||||
buf = buf.slice(nl + 1);
|
||||
const line = rawLine.endsWith("\r") ? rawLine.slice(0, -1) : rawLine;
|
||||
if (line === "") {
|
||||
const out = tryDispatch();
|
||||
if (out.matched) return out.result;
|
||||
} else if (line.startsWith(":")) {
|
||||
// SSE comment — ignore (often a keepalive)
|
||||
} else if (line.startsWith("data:")) {
|
||||
dataLines.push(line.slice(5).replace(/^ /, ""));
|
||||
}
|
||||
// event:, id:, retry: — ignored; only `data` matters for our use
|
||||
}
|
||||
}
|
||||
const out = tryDispatch();
|
||||
if (out.matched) return out.result;
|
||||
} finally {
|
||||
try { reader.cancel(); } catch {}
|
||||
}
|
||||
throw new Error(`${this.serverName}: SSE stream closed without response for id=${expectedId}`);
|
||||
}
|
||||
}
|
||||
|
||||
// ── MCP result → pi tool result helpers ──────────────────────────────────────
|
||||
|
||||
function extractText(mcpResult: any): string {
|
||||
if (!mcpResult) return "";
|
||||
const content = mcpResult.content;
|
||||
if (!Array.isArray(content)) return JSON.stringify(mcpResult);
|
||||
return content
|
||||
.map((c: any) => {
|
||||
if (c?.type === "text" && typeof c.text === "string") return c.text;
|
||||
return JSON.stringify(c);
|
||||
})
|
||||
.join("\n");
|
||||
}
|
||||
|
||||
function namespacedToolName(serverName: string, toolName: string): string {
|
||||
// Avoid double-prefix: if the MCP server already names its tools
|
||||
// `<serverName>_<...>`, leave them alone.
|
||||
const prefix = `${serverName}_`;
|
||||
const raw = toolName.startsWith(prefix) ? toolName : `${prefix}${toolName}`;
|
||||
// Sanitize for the strictest tool-name regex we have to satisfy.
|
||||
// Anthropic's Messages API allows `^[a-zA-Z0-9_-]{1,64}$` (hyphens OK),
|
||||
// but AWS Bedrock's Anthropic shim rejects names containing `-` outright
|
||||
// — it accepts `^[a-zA-Z][a-zA-Z0-9_]{0,63}$`. Hyphenated MCP tool names
|
||||
// (context7's `resolve-library-id`, `query-docs`) caused entire turns to
|
||||
// 4xx silently on Bedrock, manifesting as no output at all once the
|
||||
// server was enabled. Replace any non-[A-Za-z0-9_] with `_`, then prefix
|
||||
// a leading underscore with `t` if the result starts with a non-letter.
|
||||
// Truncate to 64 to also satisfy Anthropic's length cap.
|
||||
let sanitized = raw.replace(/[^A-Za-z0-9_]/g, "_");
|
||||
if (!/^[A-Za-z]/.test(sanitized)) sanitized = `t_${sanitized}`;
|
||||
if (sanitized.length > 64) sanitized = sanitized.slice(0, 64);
|
||||
return sanitized;
|
||||
}
|
||||
|
||||
// ── Settings.json writer ─────────────────────────────────────────────────────
|
||||
|
||||
/**
|
||||
* Flip the `enabled` flag for a server in settings.json and write back.
|
||||
* Preserves all other keys verbatim by round-tripping through JSON with
|
||||
* 2-space indent (matches the file's existing style).
|
||||
*/
|
||||
function setServerEnabled(serverName: string, enabled: boolean): void {
|
||||
const raw = fs.readFileSync(SETTINGS_PATH, "utf8");
|
||||
const parsed = JSON.parse(raw);
|
||||
if (!parsed.mcp || !parsed.mcp[serverName]) {
|
||||
throw new Error(`server '${serverName}' not in settings.json`);
|
||||
}
|
||||
if (enabled) {
|
||||
// Default is true — clear the explicit flag if present, keep the file tidy.
|
||||
delete parsed.mcp[serverName].enabled;
|
||||
} else {
|
||||
parsed.mcp[serverName].enabled = false;
|
||||
}
|
||||
fs.writeFileSync(SETTINGS_PATH, `${JSON.stringify(parsed, null, 2)}\n`, "utf8");
|
||||
}
|
||||
|
||||
// ── Per-server runtime state (for /mcp display) ──────────────────────────────
|
||||
|
||||
type ServerRuntimeState =
|
||||
| { kind: "running"; toolCount: number }
|
||||
| { kind: "failed"; message: string }
|
||||
| { kind: "disabled" }
|
||||
| { kind: "invalid"; message: string };
|
||||
|
||||
// ── Extension entry ──────────────────────────────────────────────────────────
|
||||
|
||||
export default async function mcpLoaderExtension(pi: ExtensionAPI) {
|
||||
const servers = readMcpServers();
|
||||
const runtime = new Map<string, ServerRuntimeState>();
|
||||
const clients: IMcpClient[] = [];
|
||||
|
||||
// Always register /mcp — even when no servers are configured, so users
|
||||
// discover the surface. Handler reads settings.json fresh on each invoke.
|
||||
registerMcpCommand(pi, runtime);
|
||||
|
||||
if (Object.keys(servers).length === 0) {
|
||||
dlog("no MCP servers configured — nothing to load");
|
||||
return;
|
||||
}
|
||||
|
||||
for (const [name, cfg] of Object.entries(servers)) {
|
||||
if (cfg.enabled === false) {
|
||||
dlog(`${name}: disabled in settings.json, skipping`);
|
||||
runtime.set(name, { kind: "disabled" });
|
||||
continue;
|
||||
}
|
||||
|
||||
let client: IMcpClient;
|
||||
if (cfg.type === "remote") {
|
||||
const remote = cfg as RemoteServerConfig;
|
||||
if (typeof remote.url !== "string" || remote.url.length === 0) {
|
||||
warn(`${name}: remote server missing \`url\`, skipping`);
|
||||
runtime.set(name, { kind: "invalid", message: "remote server missing url" });
|
||||
continue;
|
||||
}
|
||||
client = new RemoteMcpClient(name, remote.url, remote.headers);
|
||||
} else {
|
||||
const local = cfg as LocalServerConfig;
|
||||
if (!Array.isArray(local.command) || local.command.length === 0) {
|
||||
warn(`${name}: invalid \`command\` (must be non-empty array), skipping`);
|
||||
runtime.set(name, { kind: "invalid", message: "command must be non-empty array" });
|
||||
continue;
|
||||
}
|
||||
const [bin, ...args] = local.command;
|
||||
client = new StdioMcpClient(name, bin, args, local.env);
|
||||
}
|
||||
|
||||
try {
|
||||
await client.start();
|
||||
} catch (err) {
|
||||
const message = (err as Error).message;
|
||||
warn(`${name}: failed to start — ${message}`);
|
||||
runtime.set(name, { kind: "failed", message });
|
||||
try { await client.stop(); } catch {}
|
||||
continue;
|
||||
}
|
||||
|
||||
dlog(`${name}: connected, ${client.tools.length} tools`);
|
||||
runtime.set(name, { kind: "running", toolCount: client.tools.length });
|
||||
clients.push(client);
|
||||
|
||||
// Register each MCP tool as a pi tool.
|
||||
for (const tool of client.tools) {
|
||||
const piName = namespacedToolName(name, tool.name);
|
||||
const schema =
|
||||
tool.inputSchema && typeof tool.inputSchema === "object"
|
||||
? (Type.Unsafe<Record<string, unknown>>(
|
||||
tool.inputSchema as object,
|
||||
) as unknown as ReturnType<typeof Type.Object>)
|
||||
: Type.Object({}, { additionalProperties: true });
|
||||
|
||||
pi.registerTool({
|
||||
name: piName,
|
||||
label: piName,
|
||||
description: tool.description ?? `MCP tool from ${name}`,
|
||||
parameters: schema,
|
||||
async execute(_toolCallId, params) {
|
||||
try {
|
||||
const result = await client.callTool(tool.name, params as Record<string, unknown>);
|
||||
const text = extractText(result);
|
||||
return {
|
||||
content: [{ type: "text", text }],
|
||||
details: { server: name, tool: tool.name, raw: result },
|
||||
};
|
||||
} catch (err) {
|
||||
return {
|
||||
content: [
|
||||
{
|
||||
type: "text",
|
||||
text: `MCP call failed (${name}/${tool.name}): ${(err as Error).message}`,
|
||||
},
|
||||
],
|
||||
details: { server: name, tool: tool.name, error: (err as Error).message },
|
||||
isError: true,
|
||||
};
|
||||
}
|
||||
},
|
||||
});
|
||||
}
|
||||
}
|
||||
|
||||
// Tear down clients (stdio subprocesses, remote sessions) on session shutdown.
|
||||
pi.on("session_shutdown", async () => {
|
||||
await Promise.allSettled(clients.map((c) => Promise.resolve(c.stop())));
|
||||
});
|
||||
}
|
||||
|
||||
// ── /mcp slash command ──────────────────────────────────────────────────────
|
||||
|
||||
const VAL_ON = "● enabled";
|
||||
const VAL_OFF = "○ disabled";
|
||||
const VAL_RO = "[read-only]";
|
||||
|
||||
function statusLabel(state: ServerRuntimeState | undefined, configEnabled: boolean): string {
|
||||
if (!state) return configEnabled ? "unknown" : "disabled";
|
||||
switch (state.kind) {
|
||||
case "running":
|
||||
return `running · ${state.toolCount} tool${state.toolCount === 1 ? "" : "s"}`;
|
||||
case "failed":
|
||||
return `failed: ${state.message}`;
|
||||
case "disabled":
|
||||
return "disabled in settings";
|
||||
case "invalid":
|
||||
return `invalid: ${state.message}`;
|
||||
}
|
||||
}
|
||||
|
||||
function registerMcpCommand(pi: ExtensionAPI, runtime: Map<string, ServerRuntimeState>) {
|
||||
pi.registerCommand("mcp", {
|
||||
description: "List and toggle MCP servers configured in ~/.pi/agent/settings.json",
|
||||
handler: async (_args, ctx) => {
|
||||
const servers = readMcpServers();
|
||||
const names = Object.keys(servers);
|
||||
if (names.length === 0) {
|
||||
ctx.ui.notify(
|
||||
`No MCP servers configured. Add an \`mcp\` block to ${SETTINGS_PATH}.`,
|
||||
"info",
|
||||
);
|
||||
return;
|
||||
}
|
||||
|
||||
// Snapshot config-level enabled state (default true if unset).
|
||||
const configEnabled = new Map<string, boolean>();
|
||||
for (const [n, cfg] of Object.entries(servers)) {
|
||||
configEnabled.set(n, cfg.enabled !== false);
|
||||
}
|
||||
|
||||
// Staged state: name → enabled (initialised from configEnabled).
|
||||
const staged = new Map(configEnabled);
|
||||
|
||||
await ctx.ui.custom<void>((tui, theme, _kb, done) => {
|
||||
let statusText = "";
|
||||
|
||||
const items: SettingItem[] = names.map((n) => {
|
||||
const cfg = servers[n];
|
||||
const cfgEn = configEnabled.get(n) ?? true;
|
||||
const state = runtime.get(n);
|
||||
const isRemote = cfg.type === "remote";
|
||||
const isInvalid = state?.kind === "invalid";
|
||||
const transport = isRemote ? "remote" : "local";
|
||||
const desc = `${transport} · ${statusLabel(state, cfgEn)}`;
|
||||
|
||||
if (isInvalid) {
|
||||
return {
|
||||
id: n,
|
||||
label: n,
|
||||
currentValue: VAL_RO,
|
||||
description: desc,
|
||||
};
|
||||
}
|
||||
return {
|
||||
id: n,
|
||||
label: n,
|
||||
currentValue: cfgEn ? VAL_ON : VAL_OFF,
|
||||
values: [VAL_ON, VAL_OFF],
|
||||
description: desc,
|
||||
};
|
||||
});
|
||||
|
||||
const container = new Container();
|
||||
|
||||
container.addChild({
|
||||
render(_w: number) {
|
||||
return [
|
||||
theme.fg("accent", theme.bold("MCP servers — settings.json `mcp` block")),
|
||||
theme.fg(
|
||||
"muted",
|
||||
" space: toggle (stage) · enter: apply + reload · esc: cancel",
|
||||
),
|
||||
"",
|
||||
];
|
||||
},
|
||||
invalidate() {},
|
||||
});
|
||||
|
||||
const settingsList = new SettingsList(
|
||||
items,
|
||||
Math.min(items.length + 2, 20),
|
||||
getSettingsListTheme(),
|
||||
(id, newValue) => {
|
||||
const isInvalid = runtime.get(id)?.kind === "invalid";
|
||||
if (isInvalid) {
|
||||
settingsList.updateValue(id, VAL_RO);
|
||||
statusText = `⊘ ${id}: invalid config — fix in settings.json`;
|
||||
tui.requestRender();
|
||||
return;
|
||||
}
|
||||
const stagingEnabled = newValue === VAL_ON;
|
||||
staged.set(id, stagingEnabled);
|
||||
|
||||
const drift: string[] = [];
|
||||
for (const n of names) {
|
||||
const s = staged.get(n);
|
||||
const c = configEnabled.get(n);
|
||||
if (s !== undefined && s !== c) drift.push(`${n}→${s ? "on" : "off"}`);
|
||||
}
|
||||
statusText = drift.length ? `pending: ${drift.join(", ")}` : "";
|
||||
tui.requestRender();
|
||||
},
|
||||
() => {
|
||||
done(undefined);
|
||||
},
|
||||
);
|
||||
|
||||
container.addChild(settingsList);
|
||||
|
||||
container.addChild({
|
||||
render(_w: number) {
|
||||
if (!statusText) return [""];
|
||||
const colored = statusText.startsWith("⊘")
|
||||
? theme.fg("warning", statusText)
|
||||
: theme.fg("muted", statusText);
|
||||
return ["", colored];
|
||||
},
|
||||
invalidate() {},
|
||||
});
|
||||
|
||||
return {
|
||||
render(width: number) {
|
||||
return container.render(width);
|
||||
},
|
||||
invalidate() {
|
||||
container.invalidate();
|
||||
},
|
||||
handleInput(data: string) {
|
||||
if (matchesKey(data, Key.enter)) {
|
||||
const errors: string[] = [];
|
||||
let applied = 0;
|
||||
for (const n of names) {
|
||||
const s = staged.get(n);
|
||||
const c = configEnabled.get(n);
|
||||
if (s === undefined || s === c) continue;
|
||||
try {
|
||||
setServerEnabled(n, s);
|
||||
applied++;
|
||||
} catch (err) {
|
||||
const msg = err instanceof Error ? err.message : String(err);
|
||||
errors.push(`${n}: ${msg}`);
|
||||
}
|
||||
}
|
||||
done(undefined);
|
||||
if (errors.length) {
|
||||
ctx.ui.notify(`mcp: ${errors.join(" | ")}`, "error");
|
||||
} else if (applied > 0) {
|
||||
ctx.ui.notify(`mcp: applied ${applied} change(s); reloading…`, "info");
|
||||
ctx.reload().catch((err) => {
|
||||
const msg = err instanceof Error ? err.message : String(err);
|
||||
ctx.ui.notify(`reload failed: ${msg}`, "error");
|
||||
});
|
||||
}
|
||||
return;
|
||||
}
|
||||
settingsList.handleInput?.(data);
|
||||
tui.requestRender();
|
||||
},
|
||||
};
|
||||
});
|
||||
},
|
||||
});
|
||||
}
|
||||
Reference in New Issue
Block a user