Key error diagnosis

StepFun AI | unsupported capability

Diagnose StepFun AI unsupported capability (400) by checking balance, Base URL, model permission, region/IP, and visible models before the next fix.

Provider

StepFun AI

China provider route

Error type

unsupported capability

medium

Status code

400

unsupported-capability

Sample models

Step 3.5 Flash

Error route summary

Error type

unsupported-capability

medium

Provider

StepFun AI

Status code

400

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

What this error usually means

Diagnose StepFun AI unsupported capability (400) by checking balance, Base URL, model permission, region/IP, and visible models before the next fix.

Provider: StepFun AI
Error type: unsupported capability
Status code: 400

How to prove it during checking

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

Run read-only identity first: confirm whether the key really belongs to StepFun AI, not just a compatible protocol.
Then list models or run a lightweight probe: check whether models like Step 3.5 Flash are visible and return stable evidence.
Finally record 400, error body, latency, egress IP, and reproducibility to separate balance, permission, route, or upstream issues.

Next action

unsupported capability should not only show failed. The console should return the next move: refill balance, change Base URL, switch model, add permission, change egress IP, hold listing, or monitor.

Read-only check. Detection data burns after 5 minutes.
China provider route
Step 3.5 Flash

Open key check

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

After clarifying this error, jump back to the newest model and decide whether the failure changes how far you keep following it.