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Model error diagnosis

OpenAI: GPT-5 Pro | context length exceeded

OpenAI: GPT-5 Pro returning 400 / context length exceeded means you should first confirm whether model ID openai/gpt-5-pro is visible for this OpenAI key, then separate permission, context, capability, rate limit, or route issues.

Model
openai/gpt-5-pro
OpenAI: GPT-5 Pro
Provider
OpenAI
62 models in catalog
Error type
context length exceeded
context-exceeded
Status code
400
global model route
Model error summary
Model
openai/gpt-5-pro
Error type
context-exceeded
Status code
400
Read-only check. Detection data burns after 5 minutes.
Read-only check. Detection data burns after 5 minutes.

What this model error usually means

OpenAI: GPT-5 Pro returning 400 / context length exceeded means you should first confirm whether model ID openai/gpt-5-pro is visible for this OpenAI key, then separate permission, context, capability, rate limit, or route issues.

  • Model: openai/gpt-5-pro
  • Provider: OpenAI
  • Status code: 400

How to prove it during checking

Read-only check. Detection data burns after 5 minutes.

  • List models: confirm whether openai/gpt-5-pro is actually visible instead of guessing from the display name.
  • Light probe: use minimal input to verify whether OpenAI returns the same 400, then record the error body.
  • Compare model facts: context 400,000, input $15, output $120.
  • supports include_reasoning
  • supports max_tokens
  • supports reasoning
  • supports response_format

Next action

OpenAI: GPT-5 Pro context length exceeded should not end at failed. Return the next move: change model ID, add permission, reduce context, disable unsupported capability, change route, monitor, or hold listing.

  • Context: 400,000
  • Price: $15 / $120
  • Read-only check. Detection data burns after 5 minutes.