MCP Wayback Machine Server

MCP server and CLI tool for interacting with the Internet Archive's Wayback Machine. Supports full CDX search, snapshot content retrieval, screenshot listing, snapshot comparison, and optional authentication for higher SPN2 rate limits.

Stack: TypeScript · Node.js 22+ · ES Modules · pnpm · Turbo · Zod

Getting started

Requires Node.js 22+ and pnpm.

pnpm install

Optional credentials (anonymous access works, but authenticated requests get higher SPN2 rate limits):

export WAYBACK_ACCESS_KEY="your-access-key"
export WAYBACK_SECRET_KEY="your-secret-key"

Obtain credentials at archive.org/account/s3.php.

Build, test, and lint

pnpm validate          # typecheck + lint + build + test + untested-files check (the full CI gate)
pnpm check             # typecheck + lint + build only
pnpm build             # compile TypeScript to dist/
pnpm test              # run unit and integration tests
pnpm test:coverage     # run tests with coverage (80% line/branch/function threshold)
pnpm lint              # lint with ESLint
pnpm lint:fix          # auto-fix lint issues

To run a single test file:

node --test tests/tools/save.unit.test.ts

End-to-end tests hit the live Wayback Machine API and are opt-in:

pnpm test:e2e          # sets WAYBACK_LIVE_TESTS=1 internally via turbo

pnpm validate is the gate that must pass before a release. prepublishOnly runs it automatically.

Architecture

src/bin.ts is the entry point. It detects whether it is invoked as a CLI or loaded as an MCP server and routes accordingly.

src/
  bin.ts          — entry point; dispatches to CLI or MCP server
  cli.ts          — Commander-based CLI implementation
  server.ts       — MCP server wiring (ListTools + CallTool handlers)
  contexts.ts     — shared context (rate limiter, cache, credentials)
  schemas.ts      — Zod schemas for all tool inputs; single source of truth
  tools/
    save.ts       — save_url tool (SPN2 API)
    retrieve.ts   — get_archived_url tool
    search.ts     — search_archives tool (CDX API)
    status.ts     — check_archive_status tool (sparkline API)
    screenshots.ts — list_screenshots tool
    compare.ts    — compare_snapshots tool
    cache.ts      — clear_cache tool
    context.ts    — injects shared context into tool handlers
  utils/
    http.ts       — fetch wrapper with rate limiting and Retry-After handling
    cache.ts      — in-memory + disk cache with per-endpoint TTLs
    rate-limit.ts — 15 req/min token bucket
    validation.ts — shared Zod validation helpers

Each tool module exports a schema (consumed by ListToolsRequestSchema) and an execution function (consumed by CallToolRequestSchema). New tools need both registrations in server.ts.

Caching TTLs are intentional — do not normalise them:

Conventions

• TypeScript strict mode with noUncheckedIndexedAccess and exactOptionalPropertyTypes — no any, no as assertions.
• ES Modules throughout — "type": "module" in package.json. Always use .ts extensions in relative imports (rewritten to .js at build time via rewriteRelativeImportExtensions).
• Zod is the single source of truth for all tool input shapes. schemas.ts defines them; zodToJsonSchema derives the MCP-compatible JSON Schema.
• Prettier formats all TypeScript: 4-space indent, double quotes, trailing commas (es5), 80-char print width, LF line endings.
• Conventional commits are enforced by commitlint. Allowed scopes: retrieve, save, search, status, fetch, http, validation, cli, build, release, ci, deps. Commit messages must use British English.
• Test colocation: unit tests in tests/tools/*.unit.test.ts and tests/utils/*.unit.test.ts; integration tests in tests/*.integration.test.ts. Use the Node.js built-in test runner — no Jest or Vitest.
• erasableSyntaxOnly: true — no TypeScript syntax that cannot be stripped without transformation (no enum, no decorators, no namespace).

Gotchas

• pnpm validate before pushing. CI runs check + test + coverage + untested-files. pnpm validate replicates this locally via Turbo.
• Turbo caches aggressively. If you change a config file that Turbo doesn't track as an input, cached task results may be stale. Clear with pnpm turbo run <task> --force if results look wrong.
• WAYBACK_LIVE_TESTS must be set to run test:e2e. The Turbo config passes it through via globalPassThroughEnv; don't set it in .env files — export it in your shell before running.
• Coverage excludes src/contexts.ts, src/cli.ts, src/bin.ts, and src/tools/context.ts — these are wiring/entry-point files. The 80% threshold applies to the remaining surface.
• Rate limiting is 15 req/min across all Wayback Machine API calls, with automatic Retry-After handling for 429 responses. Tests that mock HTTP must respect this — don't call real endpoints from unit tests.
• noUncheckedIndexedAccess means Record<string, T> lookups return T | undefined. Never fall back to ?? default — narrow explicitly or restructure to a concrete type.
• Node version is pinned in .tool-versions. CI tests against Node 22, 24, and 26. Do not use Node APIs that aren't available in 22.

Contributing

Commits follow Conventional Commits and are lint-checked by commitlint on PRs. PRs target main; CI must pass (check, test, coverage). Releases are fully automated via semantic-release on push to main.

After release, alias packages (wayback-machine-mcp, mcp-internet-archive, internet-archive-mcp, @mearman/mcp-wayback-machine) are published automatically by CI — do not publish these manually.

Installation

As an MCP server

CLI shorthand

Claude Code (MCP):

claude mcp add wayback-machine -- npx -y mcp-wayback-machine

Claude Code (plugin marketplace):

/plugin marketplace add https://github.com/Mearman/mcp-wayback-machine.git
/plugin install mcp-wayback-machine@mcp-wayback-machine

OpenAI Codex:

codex mcp add wayback-machine -- npx -y mcp-wayback-machine

To include optional credentials:

claude mcp add wayback-machine --env WAYBACK_ACCESS_KEY=xxx --env WAYBACK_SECRET_KEY=xxx -- npx -y mcp-wayback-machine

Manual configuration

Add to the appropriate config file:

{
  "wayback-machine": {
    "command": "npx",
    "args": ["-y", "mcp-wayback-machine"],
    "env": {
      "WAYBACK_ACCESS_KEY": "your-access-key",
      "WAYBACK_SECRET_KEY": "your-secret-key"
    }
  }
}

The env block is optional — the server works anonymously without credentials.

As a CLI tool

npx mcp-wayback-machine save https://example.com

Or install globally:

npm install -g mcp-wayback-machine
wayback save https://example.com

As a Cloudflare Worker

Deploy the MCP server as a stateless Cloudflare Worker. Runs on the free tier with no paid bindings — all persistent state uses the Cache API which has no published daily limits.

pnpm add -D wrangler
wrangler deploy

The Worker uses the SDK's StreamableHTTPServerTransport in stateless mode (no session IDs), so each request is independent and cold starts are handled gracefully.

Environment variables (set via wrangler secret put):

When MCP_AUTH_TOKEN is set, clients must send Authorization: Bearer <token>. When absent, the Worker accepts unauthenticated requests.

Per-request credentials. Clients can pass their own IA S3 credentials on each request via HTTP headers, overriding the server's environment variables:

X-Archive-Access-Key: <your-access-key>
X-Archive-Secret-Key: <your-secret-key>

This lets multiple users share a single Worker deployment while each using their own credentials for higher SPN2 rate limits. When both headers are present, they take precedence over WAYBACK_ACCESS_KEY/WAYBACK_SECRET_KEY. When absent, the Worker falls back to its environment variables.

Worker-specific files are excluded from the main tsconfig.json and type-checked separately via tsconfig.worker.json (which adds @cloudflare/workers-types).