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Head to head · LLM inference · October 2026 research run

Cloudflare Workers AI vs StepFun API

Cloudflare Workers AI scores 68.3 (B) on agent readiness against StepFun API's 44.4 (E), and leads in every scored category. Both do llm inference.

Best model APIs and inference for AI agents · All 153 models comparisons

Cloudflare Workers AICloudflare, Inc. · Model API B68.3/100#226 of 965 StepFun APIStepFun · Model API E44.4/100#889 of 965

Which one, for what

Cloudflare Workers AI B

Best for Agents that already run on Cloudflare Workers, or that want open-weight chat, embedding, reranking, speech and image models behind one token with a free daily allowance.

Ahead on

  • Reliability, 66 against 28
  • Schema & documentation, 80 against 53
  • Agent ergonomics, 75 against 68
  • Security & auth, 77 against 41
  • Payments & pricing, 52 against 20
  • Maintenance & community, 72 against 50
  • Transparency & trust, 76 against 58

Watch for

No SLA for Workers AI was found in the docs or the agreements read

StepFun API E

Best for Long-context agent and coding work over text, screenshots and video at a low per-token price, where a preview model is acceptable.

Also in its favour

  • No incidents deducted, where Cloudflare Workers AI loses 3 points for them

Watch for

Step 5 Preview is labelled a preview, and no release date or support commitment was found

Score by category

CategoryWeight this runCloudflare Workers AIStepFun APIEdge
Reliability16%206628Cloudflare Workers AI +38
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28053Cloudflare Workers AI +27
Agent ergonomics13%16.27568Cloudflare Workers AI +7
Security & auth14%17.57741Cloudflare Workers AI +36
Payments & pricing10%12.55220Cloudflare Workers AI +32
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87250Cloudflare Workers AI +22
Transparency & trust7%8.87658Cloudflare Workers AI +18
Negative events≤15-30
TotalB 68.3/100E 44.4/100

Facts side by side

FactCloudflare Workers AIStepFun API
KindModel APIModel API
VendorCloudflare, Inc.StepFun
Hosted endpointhttps://api.cloudflare.com/client/v4/accounts/{account_id}/aihttps://api.stepfun.ai/v1
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingFreemiumPay per use
x402payer tooling onlyno
LicenceProprietary service under Cloudflare's Self-Serve Subscription Agreement. Each hosted model carries its own open-weight licence, linked from its model page. The cloudflare SDKs are Apache-2.0, workers-ai-provider is MIT and the OpenAPI repository is BSD-3-ClauseClosed service under the StepFun Open Platform Terms of Service (STEPFUN TECHNOLOGY (HK) LIMITED, Hong Kong law).
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-01none
Terms last updated2025-09-12
Privacy policy last updatedno date given
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularity380k npm/wknone

Verdicts

Cloudflare Workers AI

Per-model prices, rate limits and JSON Schemas are public, 10,000 neurons a day are free, and x402 payment is in beta on /ai/run for four models. No SLA was found, three models moved to paid-only access on 28 July 2026 with no notice, and several docs pages still use a model retired in May.

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.

Before you call either

Cloudflare Workers AI

  1. Check the model page before calling. Seven models need Workers Paid or AI Gateway credits and return 403 with code 5035 on the Free plan
  2. Read the internal code on a 429. 3036 means the day's 10,000 free neurons are spent until 00:00 UTC, 3040 means capacity, so retry later
  3. Set options.rejectIfBusy to fail fast, or add ?queueRequest=true for the batch route when the answer can wait
  4. Send the same x-session-affinity value on every turn of a session to reach the prefix cache and the cached-input price
  5. Keep paid frontier models under 20 requests a minute per model, or 50 with prepaid AI Gateway credits

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

Questions

Which is better for AI agents, Cloudflare Workers AI or StepFun API?

Cloudflare Workers AI scores 68.3 (B) on agent readiness against StepFun API's 44.4 (E), and leads in every scored category.

Do Cloudflare Workers AI and StepFun API need an API key?

Both need an API key.

Can an agent call Cloudflare Workers AI and StepFun API without installing anything?

Yes. Cloudflare Workers AI has a hosted endpoint at https://api.cloudflare.com/client/v4/accounts/{account_id}/ai and StepFun API at https://api.stepfun.ai/v1.

Other comparisons with Cloudflare Workers AI or StepFun API

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