Key error diagnosis

StepFun AI | tools unsupported

StepFun AI returning 400 / tools unsupported should not be judged from the message alone. Cross-check key shape, Base URL, balance, model permission, region/IP, and visible model list.

Provider

StepFun AI

China provider route

Error type

tools unsupported

medium

Status code

400

tools-unsupported

Sample models

Step 3.5 Flash

Error route summary

Error type

tools-unsupported

medium

Provider

StepFun AI

Status code

400

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

What this error usually means

StepFun AI returning 400 / tools unsupported should not be judged from the message alone. Cross-check key shape, Base URL, balance, model permission, region/IP, and visible model list.

Provider: StepFun AI
Error type: tools unsupported
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

tools unsupported 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 checker

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