mcpolyglot

@mcpolyglot/cli

The mcpolyglot command-line interface. Scaffolds a config, validates connectivity, lists tools, and serves the MCP server over stdio or Streamable HTTP.

npx @mcpolyglot/cli init       # interactive wizard
npx @mcpolyglot/cli doctor     # validate config, ping sources, list tools
npx @mcpolyglot/cli tools      # list tools mcpolyglot would expose
npx @mcpolyglot/cli serve      # start the MCP server (stdio)
npx @mcpolyglot/cli serve --http --port 7337   # start over Streamable HTTP

Commands

Command	Purpose
init	Interactively scaffold an mcpolyglot.config.ts in the current directory.
doctor	Load + validate config, resolve secrets, ping each source, list tools.
tools	Print every tool mcpolyglot would expose for the current config.
serve	Start the server. --http flips to Streamable HTTP with bearer auth.
token	token create <agentId> mints a per-agent token; token hash hashes one.

serve --http prints the bearer token, MCP URL, and /healthz URL on stderr. Pin the token in your config (transport.auth.token) for stable deployments; omit it to mint a fresh token on each start.

Multiple agents over HTTP

Give each agent its own token, sources and scopes. Tokens are stored only as sha256 hashes:

mcpolyglot token create analyst       # prints the token once, its hash, and a config snippet
echo -n "$TOKEN" | mcpolyglot token hash

agents: [
  {
    id: 'analyst',
    tokens: [{ hash: '<sha256 hex>', label: '2026-09' }],
    scopes: ['schema:read', 'tables:read', 'query:raw'],
    sources: { 'pg.main': { policy: { tables: { users: 'none' } } } },
  },
],

• An agent sees only tools of the sources listed under it, and only tools its scopes fully cover. scopes defaults to, and is capped at, the union of those sources' scopes.
• A per-agent policy can only narrow the source's policy: per table the most restrictive access wins, deny lists are combined, and caps take the smaller value. An agent can't re-open a table the source hides or gain writes the source doesn't grant. The reverse also holds: a table the agent's policy doesn't list falls to its defaultAccess (at most read), so an agent that should keep a source's write access must list that table as write again. It gets its own connector, so its own DB connection; sources listed without a policy share the main one.
• The token decides the audit agentId; the x-mcpolyglot-agent header is ignored when agents is set. Unknown or revoked tokens get 401.
• Rotate: add the new hash, move the client over, set revoked: true on the old one (or delete it), restart serve. There is no hot reload.
• agents needs bearer auth (not OAuth) and is ignored under stdio (single local user). doctor lists what each agent can and can't use.

Stdio servers must keep stdout clean, so all CLI output goes to stderr.

Docs

• Full README → https://github.com/ishay60/mcpolyglot
• Architecture → https://github.com/ishay60/mcpolyglot/blob/develop/ARCHITECTURE.md
• Examples → https://github.com/ishay60/mcpolyglot/tree/develop/examples

MIT licensed.