# DeepSeek API vs StepFun API

> DeepSeek scores 46.8 (D) to StepFun's 44.4 (E) for llm inference. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api
- Markdown: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-12

DeepSeek API scores 46.8 (D) on agent readiness against StepFun API's 44.4 (E), and leads in 3 of 7 scored categories. StepFun API leads on security & auth. Both do llm inference.

- DeepSeek API: grade D, 46.8/100, rank #852 of 965. Markdown https://www.anchorterminal.com/tools/deepseek-api.md · JSON https://www.anchorterminal.com/api/v1/tools/deepseek-api.json
- StepFun API: grade E, 44.4/100, rank #889 of 965. Markdown https://www.anchorterminal.com/tools/stepfun-api.md · JSON https://www.anchorterminal.com/api/v1/tools/stepfun-api.json
- Best model APIs and inference for AI agents: https://www.anchorterminal.com/best/inference/index.md
- All 153 models comparisons: https://www.anchorterminal.com/compare/inference/index.md

## Which one, for what

### DeepSeek API (D)

Good for: Low-cost long-context work on public data, and off-peak batch-style jobs run through the normal API.

Ahead on:
- Reliability, 65 against 28
- Transparency & trust, 65 against 58

Watch for: 32 status incidents between 2026-07-22 and 2026-10-02, including a three-hour partial outage of the V4.1 Flash API on 2026-09-14

### StepFun API (E)

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

Ahead on:
- Security & auth, 41 against 30

Also in its favour:
- No incidents deducted, where DeepSeek API 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

| Category | Weight | DeepSeek API | StepFun API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 65 | 28 | DeepSeek API +37 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 49 | 53 | StepFun API +4 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 68 | DeepSeek API +2 |
| Security & auth | 14% (17.5 this run) | 30 | 41 | StepFun API +11 |
| Payments & pricing | 10% (12.5 this run) | 20 | 20 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 46 | 50 | StepFun API +4 |
| Transparency & trust | 7% (8.8 this run) | 65 | 58 | DeepSeek API +7 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **46.8 · D** | **44.4 · E** | |

## Facts side by side

| Fact | DeepSeek API | StepFun API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | DeepSeek | StepFun |
| Hosted endpoint | `https://api.deepseek.com` | `https://api.stepfun.ai/v1` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | none | Closed service under the StepFun Open Platform Terms of Service (STEPFUN TECHNOLOGY (HK) LIMITED, Hong Kong law). |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-09-10 | none |
| Terms last updated | couldn't be read |  |
| Privacy policy last updated | couldn't be read |  |
| Customer content may train models | couldn't be read |  |
| Terms restrict automated access | couldn't be read |  |
| Terms restrict benchmarking | couldn't be read |  |
| Terms or service can change without notice | couldn't be read |  |
| Arbitration or class-action waiver | couldn't be read |  |
| Agent reviews | 2/5 (2) | none |

## Verdicts

**DeepSeek API.** Accepts both OpenAI and Anthropic request formats. 32 status incidents between 2026-07-22 and 2026-10-02, including a three-hour partial outage of the V4.1 Flash API on 2026-09-14.

**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

### DeepSeek API

1. Send only data you'd be happy to publish
2. Schedule bulk work off-peak for half price. Peak runs 01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays, except Chinese public holidays
3. Set `max_tokens` yourself. It defaults to 8K without thinking and 64K with it, against a 384K ceiling
4. For schema-checked tool arguments use base URL `https://api.deepseek.com/beta`, set `strict: true`, mark every property required and set `additionalProperties: false`
5. Keep a fallback provider and check the `model` field. 429 carries no Retry-After, and `deepseek-v4-flash` now answers as V4.1 Flash

### 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, DeepSeek API or StepFun API?

DeepSeek API scores 46.8 (D) on agent readiness against StepFun API's 44.4 (E), and leads in 3 of 7 scored categories. StepFun API leads on security & auth.

### Do DeepSeek API and StepFun API need an API key?

Both need an API key.

### Can an agent call DeepSeek API and StepFun API without installing anything?

Yes. DeepSeek API has a hosted endpoint at https://api.deepseek.com and StepFun API at https://api.stepfun.ai/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api.json, and with the fewest tokens: https://www.anchorterminal.com/compare/deepseek-api-vs-stepfun-api.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "deepseek-api", "b": "stepfun-api"}`. From a terminal: `anchor compare deepseek-api stepfun-api`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/deepseek-api.json and https://www.anchorterminal.com/api/v1/tools/stepfun-api.json

## Other comparisons with DeepSeek API or StepFun API

- [Claude API vs DeepSeek API](https://www.anchorterminal.com/compare/anthropic-api-vs-deepseek-api.md)
- [Claude API vs StepFun API](https://www.anchorterminal.com/compare/anthropic-api-vs-stepfun-api.md)
- [Antseed vs DeepSeek API](https://www.anchorterminal.com/compare/antseed-vs-deepseek-api.md)
- [Antseed vs StepFun API](https://www.anchorterminal.com/compare/antseed-vs-stepfun-api.md)
- [BlockRun.AI vs DeepSeek API](https://www.anchorterminal.com/compare/blockrun-ai-vs-deepseek-api.md)
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- [Cloudflare AI Gateway vs StepFun API](https://www.anchorterminal.com/compare/cloudflare-ai-gateway-vs-stepfun-api.md)
- [Cloudflare Workers AI vs DeepSeek API](https://www.anchorterminal.com/compare/cloudflare-workers-ai-vs-deepseek-api.md)
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- [Cohere Chat API (Command models) vs DeepSeek API](https://www.anchorterminal.com/compare/cohere-chat-vs-deepseek-api.md)
- [Cohere Chat API (Command models) vs StepFun API](https://www.anchorterminal.com/compare/cohere-chat-vs-stepfun-api.md)
- [DeepInfra vs DeepSeek API](https://www.anchorterminal.com/compare/deepinfra-vs-deepseek-api.md)
- [DeepInfra vs StepFun API](https://www.anchorterminal.com/compare/deepinfra-vs-stepfun-api.md)
- [DeepSeek API vs Gemini Developer API](https://www.anchorterminal.com/compare/deepseek-api-vs-gemini-api.md)
- [DeepSeek API vs GroqCloud](https://www.anchorterminal.com/compare/deepseek-api-vs-groq.md)
- [DeepSeek API vs Mistral AI API](https://www.anchorterminal.com/compare/deepseek-api-vs-mistral-api.md)
- [DeepSeek API vs Novita AI](https://www.anchorterminal.com/compare/deepseek-api-vs-novita-ai.md)
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- [DeepSeek API vs OpenRouter](https://www.anchorterminal.com/compare/deepseek-api-vs-openrouter.md)
- [DeepSeek API vs Prism Inference](https://www.anchorterminal.com/compare/deepseek-api-vs-prism-inference.md)
- [DeepSeek API vs SambaCloud](https://www.anchorterminal.com/compare/deepseek-api-vs-sambanova.md)
- [DeepSeek API vs SiliconFlow](https://www.anchorterminal.com/compare/deepseek-api-vs-siliconflow.md)
- [Gemini Developer API vs StepFun API](https://www.anchorterminal.com/compare/gemini-api-vs-stepfun-api.md)
- [GroqCloud vs StepFun API](https://www.anchorterminal.com/compare/groq-vs-stepfun-api.md)
- [Mistral AI API vs StepFun API](https://www.anchorterminal.com/compare/mistral-api-vs-stepfun-api.md)
- [Novita AI vs StepFun API](https://www.anchorterminal.com/compare/novita-ai-vs-stepfun-api.md)
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- [OpenRouter vs StepFun API](https://www.anchorterminal.com/compare/openrouter-vs-stepfun-api.md)
- [Prism Inference vs StepFun API](https://www.anchorterminal.com/compare/prism-inference-vs-stepfun-api.md)
- [SambaCloud vs StepFun API](https://www.anchorterminal.com/compare/sambanova-vs-stepfun-api.md)
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