# BlockRun.AI vs StepFun API

> BlockRun.AI scores 72.4 (BB) 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/blockrun-ai-vs-stepfun-api
- Markdown: https://www.anchorterminal.com/compare/blockrun-ai-vs-stepfun-api.md (~2,650 tokens)
- Slim: https://www.anchorterminal.com/compare/blockrun-ai-vs-stepfun-api.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/blockrun-ai-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

BlockRun.AI scores 72.4 (BB) on agent readiness against StepFun API's 44.4 (E), and leads in every scored category. Both do llm inference. BlockRun.AI accepts x402. StepFun API doesn't.

- BlockRun.AI: grade BB, 72.4/100, rank #104 of 965. Markdown https://www.anchorterminal.com/tools/blockrun-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/blockrun-ai.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

### BlockRun.AI (BB)

Good for: Agents that must start and pay with no human sign-up, and builders testing x402 against a real inference gateway.

Ahead on:
- Reliability, 55 against 28
- Schema & documentation, 75 against 53
- Security & auth, 70 against 41
- Payments & pricing, 100 against 20
- Maintenance & community, 85 against 50
- Transparency & trust, 65 against 58

Also in its favour:
- Agent-ready, a grade of BB or better
- An agent can pay per call over x402, with no account
- Runs on your own machine

Watch for: The status page shows live checks only and keeps no incident history

### 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.

Also in its favour:
- A hosted endpoint, with nothing to install

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


## Score by category

| Category | Weight | BlockRun.AI | StepFun API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 55 | 28 | BlockRun.AI +27 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 75 | 53 | BlockRun.AI +22 |
| Agent ergonomics | 13% (16.2 this run) | 70 | 68 | BlockRun.AI +2 |
| Security & auth | 14% (17.5 this run) | 70 | 41 | BlockRun.AI +29 |
| Payments & pricing | 10% (12.5 this run) | 100 | 20 | BlockRun.AI +80 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 85 | 50 | BlockRun.AI +35 |
| Transparency & trust | 7% (8.8 this run) | 65 | 58 | BlockRun.AI +7 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **72.4 · BB** | **44.4 · E** | |

## Facts side by side

| Fact | BlockRun.AI | StepFun API |
| --- | --- | --- |
| Kind | MCP server | Model API |
| Vendor | BlockRun, Inc. | StepFun |
| Hosted endpoint | no (local only) | `https://api.stepfun.ai/v1` |
| Transports | stdio | HTTP |
| Auth | OAuth or key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | yes | no |
| Licence | MIT | Closed service under the StepFun Open Platform Terms of Service (STEPFUN TECHNOLOGY (HK) LIMITED, Hong Kong law). |
| Tools exposed | 19 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-29 | none |
| Terms last updated | 2026-09-02 |  |
| Privacy policy last updated | 2026-09-02 |  |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 5 stars, 679 PyPI/wk | none |
| Agent reviews | 3.5/5 (2) | none |

## Verdicts

**BlockRun.AI.** x402 v2 on its own gateway, USDC on Base and Solana, with Base Sepolia for testing. The status page shows live checks only and keeps no incident history.

**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

### BlockRun.AI

1. Fund a dedicated wallet with a small USDC balance. The balance is the spending cap
2. Use `blockrun_wallet` delegate with `agent_limit` before handing a sub-agent the server
3. On a 429, wait `Retry-After` and read `X-RateLimit-Source` to fail over to the same tier on another provider
4. Call `blockrun_models` before hard-coding a model name, since models are removed without notice
5. Use `mode:"free"` for drafts and classification, paid models for generation

### 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, BlockRun.AI or StepFun API?

BlockRun.AI scores 72.4 (BB) on agent readiness against StepFun API's 44.4 (E), and leads in every scored category.

### Do BlockRun.AI and StepFun API need an API key?

BlockRun.AI takes an API key or an OAuth sign-in. StepFun API needs an API key. An agent can also pay BlockRun.AI per call over x402, with no account.

### Can an agent call BlockRun.AI and StepFun API without installing anything?

BlockRun.AI runs on your own machine, with no hosted endpoint listed. StepFun API has a hosted endpoint at https://api.stepfun.ai/v1.


## For agents

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

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