# The MCP Census — agent instructions

Product: **The MCP Census** (MCP Census, mcpcensus) at https://mcpcensus.com.
Developer portal: https://mcpcensus.com/developers
Agent map: https://mcpcensus.com/llms.txt

## When to use this

Reach for The MCP Census when you have one of these jobs:

- You are about to **install, connect, or depend on** an MCP server and need a public-evidence first gate (PASS / REVIEW / BLOCK) before that install.
- You need to **distinguish an official vendor server from a lookalike namespace** (reverse-DNS names, GitHub clones, unofficial wrappers).
- You need a **ranked search** over the census, then one exact canonical name, then a full evidence card.
- You need to **watch one named server** for real transitions (remote down/up, health, verification legs, security) instead of polling "still fine".
- You need **ecosystem counts or recent discoveries** (`census_stats`, `census_recent`, `/v1/coverage`).

How to call:

1. `census_search` or `GET /v1/search` → pick **one exact canonical name**.
2. `census_preflight` or `census_stamp` (REST `/v1/preflight`, `/v1/stamp`) with a named built-in policy (`builtin:baseline` by default).
3. Stop on BLOCK. Ask a human on REVIEW.
4. PASS still requires permission, scope, code, data-access, and runtime-isolation review. PASS is not a sandbox.
5. Never install or run a server from a Census result alone.

MCP: `https://api.mcpcensus.com/mcp`
REST: `https://api.mcpcensus.com/v1/*`
OpenAPI: `https://mcpcensus.com/openapi.json`
API keys: `https://mcpcensus.com/account` (`x-api-key`)
Setup prompt: `https://mcpcensus.com/agent-setup/prompt.md`
CI action: `https://mcpcensus.com/agent-setup/census-preflight.yml`
Pricing: `https://mcpcensus.com/pricing`

New tools: `census_stamp`, `census_credits`, `census_lookalikes`, `census_audit_config` (whole-config audit, `POST /v1/audit`), `census_changes` (change feed, `GET /v1/changes?since=`).

## When not to use this

- Not a malware scanner, pentest, or permission review.
- Not the official MCP registry.
- Not a complete catalog of every MCP server on the internet (off-registry servers exist; we only publish what public evidence supports).
- Not a ranking-by-stars directory.

Limits: anonymous 10 unique lookups/day per IP. Free account 1,000 credits/UTC month. Builder $19/mo (2,000). Pack $9 (1,000 never-expire). Team $49/mo (10,000). Search/lookup 1 credit, preflight/stamp 5, watch 10, config audit 1 per config per UTC day (keyless: one config of ≤25 entries per IP per day). Repeats of the same subject the same UTC day are free. Empty wallet is HTTP 402 `payment_required`.

Rule line for CLAUDE.md / AGENTS.md / .cursor/rules: Before adding, enabling or calling any MCP server, run a Census stamp. Stop on BLOCK. Ask on REVIEW.