MCP Ecosystem

Sourcey's MCP support is built on two standalone npm packages published under the sourcey org. They're useful independently of sourcey for any project that works with MCP server specifications.

mcp-schema

TypeScript types and JSON Schema for the mcp.json snapshot format.

npm install mcp-schema

import type { McpSpec, McpTool, McpResource } from "mcp-schema";
import { mcpSpecSchema } from "mcp-schema/schema";

Provides typed interfaces for the full MCP surface: tools (with inputSchema, outputSchema, annotations), resources, resource templates, prompts, server capabilities, and transport configuration. The JSON Schema can be used with any validator (Ajv, Zod, etc.).

Zero runtime dependencies.

• GitHub
• npm

mcp-parser

Snapshot, parse, validate, and document MCP server specifications.

npm install mcp-parser

import { parse, validate, snapshot, generateMarkdown } from "mcp-parser";

const spec = await parse("./mcp.json");
const result = validate(spec);
const markdown = generateMarkdown(spec);

API

CLI

mcp-parser parse ./mcp.json
mcp-parser validate ./mcp.json
mcp-parser snapshot --stdio "node server.js" -o mcp.json
mcp-parser snapshot --sse http://localhost:3000/sse -o mcp.json
mcp-parser snapshot --http http://localhost:3000/mcp -o mcp.json
mcp-parser generate ./mcp.json -o mcp.md
mcp-parser generate ./mcp.json --format llms-txt -o llms.txt

Depends on mcp-schema for types.

• GitHub
• npm

How they fit into sourcey

Sourcey depends on mcp-parser (which brings mcp-schema transitively). When you add an mcp tab to your config, sourcey uses mcp-parser to parse the mcp.json file and then normalizes it into the same internal format used for OpenAPI specs. The rendering pipeline, search, navigation, and theming work identically.

You don't need to install mcp-parser or mcp-schema separately to use MCP tabs in sourcey. They're included as dependencies.

MCP protocol revisions

Three different things sit behind this question, and they answer it differently.

The mcp.json format (mcp-schema) is revision-independent. It records which revision a snapshot came from, validating it as a YYYY-MM-DD shape rather than against a list of known revisions, so a document produced against a revision newer than the package still validates.

The snapshot client (mcp-parser) requests 2025-11-25 by default and, from 0.4.2, any other revision on request. A handshake revision is offered in initialize, and later requests declare the revision the server negotiates. A stateless revision (2026-07-28 and later) is declared on every request in _meta, and the snapshot reads server/discover instead of initialize, recording the server's supported revisions as mcpVersions.

The hosted Sourcey MCP server at mcp.sourcey.com/mcp works with every MCP client on Streamable HTTP. It serves every published revision on one endpoint:

A revision outside that set is refused with 400 and the complete set of revisions the server serves, so a client can retry with one it shares. Each request carries one JSON-RPC message; batches are refused. The hosted manifest at mcp.sourcey.com/mcp.json lists the same set as mcpVersions, and the set is declared once in Sourcey's MCP contract. Every deploy's live check proves each declared revision and rolls the release back on any failure, and mcp-parser can snapshot the endpoint at any of them.

MCP specification resources

• MCP Specification (current revision)
• MCP Specification 2025-11-25 (the newest handshake revision)
• Specification repo
• TypeScript SDK (@modelcontextprotocol/sdk)
• Python SDK (mcp on PyPI)