Authentication & Rate Limits
Concessio uses API keys for authentication. Pass your key via the Authorization header. API keys are tied to your organization and plan tier.
How do I authenticate to the Concessio API?
Authorization: Bearer ck_live_xxxxxxxxxxxx
Key format: ck_live_ followed by 48 hex characters. Keys are issued by Concessio to Enterprise customers and approved data partners; there is no self-serve sign-up. Each key carries a plan tier that sets the fields returned and the hourly request limit.
What are the rate limits per plan?
| Plan | Rate Limit | Access |
|---|---|---|
| Screen | 100 req/hr | Search + basic fields |
| Advise | 500 req/hr | Full detail + financials + ownership |
| Manage | 2,000 req/hr | Full detail + portfolio + bulk |
The MCP server uses the same key.
Error Responses
| Status | Code | Description |
|---|---|---|
| 400 | invalid_params | Malformed query parameters |
| 401 | unauthorized | Missing or invalid API key |
| 403 | plan_restricted | Endpoint not available on current plan |
| 404 | not_found | Concession ID does not exist |
| 429 | rate_limited | Rate limit exceeded — includes retry_after |
| 500 | internal_error | Server error |