Cohere Rerank API Errors and Truncated Documents

How to fix it

Try these in order — the most common fix is first.

1. 1. Validate the request

   Copy steps
   1. Send model, query and documents as the reference describes
   2. Format structured data as YAML strings
   3. Read the id and message fields in the error body
   Did this fix it? Yes No

2. 2. Batch and chunk

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   1. Split document sets above 1,000 into batches and merge scores
   2. Chunk long documents under max_tokens_per_doc
   3. Use top_n to limit results
   Did this fix it? Yes No

3. 3. Handle rate limits and 503

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   1. Retry with backoff on 429 and 503
   2. Production Rerank limit is 1,000 requests per minute
   Did this fix it? Yes No

Symptoms

Rerank returns 400, 422, 429 or 5xx, or relevant passages seem ignored.

Why it happens

• Missing or invalid fields (model, query, documents)
• More than about 1,000 documents in one request (recommended limit)
• Documents longer than max_tokens_per_doc (default 4096) are truncated
• Trial Rerank limit of 10 requests per minute
• Using retired rerank v2 model names

This guide also covers

• cohere rerank error
• cohere rerank 422
• cohere rerank documents limit

The same problem in other apps

All not loading, error messages & connection guides →

• Claude API 529 Overloaded Error (Anthropic Claude)

Other Cohere errors

• Cohere API 429 Too Many Requests Error
• Cohere Trial Key Limits and 'Not for Production' Error
• Cohere 401 Invalid API Token Error
• Cohere Model Not Found Error (Deprecated Models)
• Cohere Embed Input Too Long or Too Many Texts Error
• Cohere API 500 / 503 / 504 Server Errors
• Cohere 'Too Many Tokens' Context Length Error
• How to Cancel Cohere (Delete Account and Stop Billing)