Novita AI vs StepFun API

Novita AI

Per-token prices for about 140 language models are public, and each key can carry an expiry, a model allowlist and a source IP allowlist. No status page, SLA or security.txt was found, the per-model rate limit figures are drawn by script, and both vendor SDK repositories are archived while the docs still point to them.

StepFun API

StepFun's API serves Step 5 Preview with a 1M-token context, video input, strict JSON Schema output and published per-token prices, documented in Markdown with an llms.txt. The model is a preview with no release date found, there's no free allowance or SLA, and the terms and privacy policy leave room to train on customer data.

Novita AI

1. Set the OpenAI client base URL to https://api.novita.ai/openai and send the key as Authorization: Bearer. Keys start with sk_
2. Do not close a connection to stop generation. A request that reached the model is billed in full under status 499, so cap output with max_tokens
3. On 429, check whether the code is RATE_LIMIT_EXCEEDED or TOKEN_LIMIT_EXCEEDED and back off exponentially. No Retry-After header is documented
4. Read the changelog for retirement notices before pinning a model id. One retirement in October 2026 came with 11 days' notice
5. Ask the account owner for a key with an expiry, a model access policy and an IP allowlist. Keys are created and deleted only in the console

StepFun API

1. Set max_tokens yourself. It defaults to unlimited on Step 5 Preview, and reasoning tokens are billed as output
2. Use response_format with type: json_schema and strict: true when the shape matters. JSON Mode alone isn't schema-checked
3. Back off and retry on 429, 500, 503 and 504. The docs give no Retry-After header or backoff schedule
4. Expect HTTP 451 or finish_reason: content_filter when content fails StepFun's review, and don't retry the same input
5. Use api.stepfun.ai for the international platform. api.stepfun.com is the China platform with yuan pricing