The MCP Census

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Vet any MCP server before you depend on it. Stamp: PASS, REVIEW, or BLOCK.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "The MCP Census": {
      "url": "https://api.mcpcensus.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (15)

• census_lookup

  Get the live health verdict for one MCP server by its exact registry name (e.g. 'io.github.owner/name'). Returns stars, last-push recency, gone/archived/deprecated flags, name-collision count, and a fact-based health verdict (healthy | issues | unknown).

  Parameters:

  • name (required) — string — Exact MCP registry server name

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_search

  Search MCP servers by keyword or partial name (e.g. 'github', 'postgres'). Returns ranked matches with health/trust. Also returns: resolved_query (auto typo fix), disambiguate (when unsure), known_brand (we recognize a strong product but it has no official MCP — e.g. CodeRabbit), research (watchlist/confirmed_absent), query_intent (brand_lookup|category|package|install_gate|junk — does not change ranking), intent_cta (preflight when they asked an install-gate question). Prefer official_match=true rows. Never invent servers.

  Parameters:

  • query (required) — string — Keyword or partial server name (>= 2 chars). Typos and space variants are resolved when confident.
  • limit — number — Max results 1–50 (default 20)

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_stats

  Ecosystem headline numbers from the live census (same payload as GET /v1/stats). Unmetered. Returns total servers, healthy/issues counts, popular (gh_stars>=1000), remote-capable count, github-linked count, and captured_at. No invented metrics.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_recent

  Newest MCP servers by real first_seen_at (same payload as GET /v1/recent). Unmetered. Only rows with a known first-seen date — never invents or guesses discovery times. Optional limit 1–50 (default 20).

  Parameters:

  • limit — number — Max results 1–50 (default 20)

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_coverage

  Public transparency report (same payload as GET /v1/coverage). Unmetered. Live D1 census/identity/remote/protocol/adoption/pipeline counts plus method notes — never invents completeness percentages or a brand_audit punch list.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_watch_subscribe

  Subscribe this agent (or a human email) to alerts for ONE specific MCP server. Fires only on real observed changes: remote_down, remote_up, health_change, verified_change, security. Requires x-api-key. Prefer webhook_url (https) so your agent can receive POST callbacks; email optional. Returns a watch id + HMAC secret (X-Census-Signature: sha256=…). Free tier: 5 watches; pro: 50.

  Parameters:

  • server_name (required) — string — Exact registry name to watch
  • email — string — Optional human email for the same alerts
  • label — string — Optional agent-chosen label
  • events — array — Subset of remote_down,remote_up,health_change,verified_change,security,tools_changed (default: all)
  • webhook_url — string — https URL that will receive signed POST event payloads

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_watch_list

  List active per-server watches for this API key. Requires x-api-key.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_watch_unsubscribe

  Deactivate a watch by id. Requires x-api-key that owns the watch.

  Parameters:

  • id (required) — string — Watch id from census_watch_subscribe

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_preflight

  Evaluate one exact MCP server under a documented built-in install policy. Returns PASS, REVIEW, or BLOCK with evidence reasons, freshness, digests, and explicit limits. This is a first gate, not a security audit. refresh=if_stale requires x-api-key.

  Parameters:

  • server_name (required) — string — Exact canonical Census server name
  • refresh — string
  • policy_id — string

  Hints: read-only no · destructive no · idempotent no · open-world yes

• census_policy_list read-only

  List the exact immutable Preflight v1 built-in policy objects, canonical ruleset, and policy digests. Unmetered.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• census_credits

  Show remaining Census credits for this API key (wallet after the UTC-month grant). Unmetered. Without a key, returns anonymous unique-per-day remaining — not a wallet.

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_stamp

  Census stamp for one exact MCP server under a built-in policy. Same input as census_preflight. Returns the preflight body plus compact CENSUS-STAMP/1 text and stamp_json. Cost matches preflight. Never connect without a stamp. PASS is not a malware scan or permission review.

  Parameters:

  • server_name (required) — string — Exact canonical Census server name
  • refresh — string
  • policy_id — string

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_lookalikes

  Contested identity for one exact server_name: official_for, name_collision_count, and up to 10 other census server_name values sharing the same namespace brand or tail. Never invents lookalikes. Cost 1.

  Parameters:

  • server_name (required) — string — Exact canonical Census server name

  Hints: read-only not declared · destructive not declared · idempotent not declared · open-world not declared

• census_audit_config

  Audit a whole MCP client config in one call (.mcp.json, claude_desktop_config.json, .cursor/mcp.json, .vscode/mcp.json, Codex config.toml text). Resolves every entry without guessing (url → remote_url, npx → npm package, uvx → PyPI package) and returns one PASS / REVIEW / BLOCK / UNKNOWN verdict per entry under a built-in policy, plus CENSUS-AUDIT/1 text, valid_until_epoch and exit_code (1 on any BLOCK). UNKNOWN is never upgraded to PASS. Cost 1 credit per config per UTC day; keyless callers get one config of ≤25 entries per IP per day. Not a malware scan; PASS is not a sandbox. Strip env/headers before sending.

  Parameters:

  • config (required) — The config document: an object with mcpServers | servers | mcp_servers, a list under entries[], or raw text (JSON or Codex config.toml)
  • format — string
  • strict — boolean — exit_code 2 when any entry is REVIEW or UNKNOWN
  • policy_id — string
  • previous_tools_digests — object — alias → tools_digest from your last audit; sets tools_drift per entry

  Hints: read-only no · destructive no · idempotent no · open-world yes

• census_changes read-only

  The Census change feed (CENSUS-CHANGES/1): observed transitions across every server — server_new, remote_down, remote_up, tools_changed, health_change, verified_change, security, endpoint_moved, registry_status, spec_era_change. Cursor-paginated: pass next_cursor back as since. Filter by events, server_names or namespace_domain. Only real transitions, never 'still fine'. Unmetered in v1; poll hourly. Not a malware scan.

  Parameters:

  • limit — integer
  • since — string — next_cursor from the previous page, or an RFC 3339 time for the first call
  • events — array — Event names to include (default all)
  • server_names — array — Exact canonical names to include (≤50)
  • namespace_domain — string — Registrable domain of a DNS-verified namespace, e.g. notion.com

  Hints: read-only yes · destructive no · idempotent yes · open-world no

Publisher website

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.