Model error diagnosis

StepFun: Step 3.5 Flash | model capability unsupported

StepFun: Step 3.5 Flash returning 400 / model capability unsupported means you should first confirm whether model ID stepfun/step-3.5-flash is visible for this StepFun AI key, then separate permission, context, capability, rate limit, or route issues.

Model

stepfun/step-3.5-flash

StepFun: Step 3.5 Flash

Provider

StepFun AI

1 models in catalog

Error type

model capability unsupported

capability-unsupported

Status code

400

China model route

Model error summary

Model

stepfun/step-3.5-flash

Error type

capability-unsupported

Status code

400

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

What this model error usually means

StepFun: Step 3.5 Flash returning 400 / model capability unsupported means you should first confirm whether model ID stepfun/step-3.5-flash is visible for this StepFun AI key, then separate permission, context, capability, rate limit, or route issues.

Model: stepfun/step-3.5-flash
Provider: StepFun AI
Status code: 400

How to prove it during checking

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

List models: confirm whether stepfun/step-3.5-flash is actually visible instead of guessing from the display name.
Light probe: use minimal input to verify whether StepFun AI returns the same 400, then record the error body.
Compare model facts: context 262,144, input $0.100, output $0.300.
supports frequency_penalty
supports include_reasoning
supports max_tokens
supports min_p

Next action

StepFun: Step 3.5 Flash 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: 262,144
Price: $0.100 / $0.300
Read-only check. Detection data burns after 5 minutes.

Open key checker

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

Open models

StepFun: Step 3.5 Flash

Open providers

StepFun AI