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Errors and limits
Errors come back as JSON with an error field and a status code of 400, 401, 403, 404, 409, 429, 500 or 503. On the v2 routes each key defaults to 60 requests a minute and 10,000 a day. Lists use limit and offset, with a maximum of 100 per page.
Published by Sellinger AI. Numbers and settings checked on 19 October 2026 against the fact register. Report an error.
Status codes
| Code | Meaning | Example body |
|---|---|---|
| 400 | The request is malformed or a field is invalid | {"error":"linkedin_profile_url is required"} |
| 401 | No key, a bad key, a revoked key or an expired key | {"error":"Authentication failed","message":"Invalid API key"} |
| 403 | The key lacks the scope, belongs to another team, or the user is a Viewer | {"error":"API key is missing the required scope: leads:write"} |
| 404 | The record does not exist | {"error":"..."} |
| 409 | The lead already exists | {"error":"Lead already exists","existing_lead_id":"..."} |
| 429 | Rate limit reached on a v2 route | {"error":"Rate limit exceeded: 60 requests per minute"} |
| 500 | An error on our side | {"error":"..."} |
| 503 | Key lookup is temporarily unavailable. Try again | {"error":"Authentication unavailable"} |
A missing key returns 401 with the message Provide API key via Authorization: Bearer <key> or X-API-Key header. The API does not use 422.
Rate limits
- Each key has a default of 60 requests per minute and 10,000 per day. The limits are enforced on the v2 MCP routes and answer 429.
- The 429 response does not carry a Retry-After or X-RateLimit header. Wait a minute and retry with backoff.
- Do not read the v1 routes as unmetered. Every call is logged against the key, and limits may be applied there.
- OAuth sessions for the MCP connector have their own, higher budget.
- If the limit check itself fails, requests are let through rather than blocked.
Pagination and bulk limits
| Route | Parameters | Default | Maximum |
|---|---|---|---|
| GET /api/v1/leads and /api/v1/activity | limit, offset | 50 | 100 |
| v2 MCP list routes | limit, offset | 25 | 100 |
The page and per_page parameters are rejected. Bulk calls accept up to 500 lead ids.
Duplicates and retries
There is no idempotency key. Duplicate leads are stopped by the LinkedIn profile URL and account, which returns 409 with the existing id. It is safe to retry a lead create after a timeout and treat 409 as success.
Common questions
Can I raise my rate limit?
Why did I get 403 and not 401?
Is there a status page for the API?
Sources and method
Sellinger API code read on 19 October 2026. The in-app reference is at app.sellinger.ai/docs. No OpenAPI file exists yet.
Related: Quickstart, Authentication, MCP connector.
