Authentication
Free access requires no key. Pro access uses an API key in the Authorization header.
Free tier — no key required
All /api/v1/* endpoints are public. No account, no key, no headers needed:
curl
curl "https://agentrank-ai.com/api/v1/search?q=database"
Rate limit: 100 requests per minute per IP. No daily cap. See Rate Limits for headers and 429 handling.
Pro tier — API key
Pro keys unlock /api/v2/* endpoints with rank history, batch lookups, and higher daily limits.
Getting a key
Get a Pro API key from agentrank-ai.com/pricing/. After purchase, your key is shown once — save it immediately.
Key format
Tier Key prefix Daily limit
Free
— (no key) 100 req/min per IP Pro
ark_pro_... 10,000 req/day Enterprise
ark_enterprise_... Unlimited Sending the key
Pass the key in the Authorization header using the Bearer scheme:
curl
curl -H "Authorization: Bearer ark_pro_your_key_here" \
"https://agentrank-ai.com/api/v2/search?q=database"
Or with the SDK — pass the key at construction:
TS
const ar = new AgentRank({'apiKey: 'ark_pro_your_key_here''}); TS
import { AgentRank } from '@agentrank/sdk';
const ar = new AgentRank({ apiKey: 'ark_pro_your_key_here' });
// All requests now use /api/v2/* automatically Authentication errors
Status Error Cause
401
Missing Authorization header Called a v2 endpoint without a key 401
Invalid API key Key not recognized 401
API key has been revoked Key was disabled 403
Batch endpoint requires Pro or Enterprise Free key used on Pro-only endpoint 429
Daily limit exceeded 10,000 req/day Pro limit reached Error responses are JSON with an error field:
JSON
{ "error": "Invalid API key." } Security
- API keys are stored as hashed values. Only the key prefix (
ark_pro_a1b2c3d4e5f6) is stored in plain text for identification. - Never expose your API key in client-side code or public repositories.
- Use environment variables:
AGENTRANK_API_KEY=ark_pro_... - If a key is compromised, contact support to revoke it immediately.