Model error diagnosis

OpenAI: GPT-5.4 Pro | model capability unsupported

OpenAI: GPT-5.4 Pro returning 400 / model capability unsupported means you should first confirm whether model ID openai/gpt-5.4-pro is visible for this OpenAI key, then separate permission, context, capability, rate limit, or route issues.

Model

openai/gpt-5.4-pro

OpenAI: GPT-5.4 Pro

Provider

OpenAI

62 models in catalog

Error type

model capability unsupported

capability-unsupported

Status code

400

global model route

Model error summary

Model

openai/gpt-5.4-pro

Error type

capability-unsupported

Status code

400

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

What this model error usually means

OpenAI: GPT-5.4 Pro returning 400 / model capability unsupported means you should first confirm whether model ID openai/gpt-5.4-pro is visible for this OpenAI key, then separate permission, context, capability, rate limit, or route issues.

Model: openai/gpt-5.4-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-5.4-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 1,050,000, input $30, output $180.
supports include_reasoning
supports max_completion_tokens
supports max_tokens
supports reasoning

Next action

OpenAI: GPT-5.4 Pro model capability unsupported 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: 1,050,000
Price: $30 / $180
Read-only check. Detection data burns after 5 minutes.

Open key checker

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