# Claude API vs Antseed

> Claude API scores 77.3 (BB) on agent readiness against Antseed's 55.1 (C), and leads in 5 of 7 scored categories. Antseed leads on payments & pricing. Both do llm inference. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/anthropic-api-vs-antseed
- Markdown: https://www.anchorterminal.com/compare/anthropic-api-vs-antseed.md (~2,350 tokens)
- Slim: https://www.anchorterminal.com/compare/anthropic-api-vs-antseed.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/anthropic-api-vs-antseed.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: 2026-10-08

Claude API scores 77.3 (BB) on agent readiness against Antseed's 55.1 (C), and leads in 5 of 7 scored categories. Antseed leads on payments & pricing. Both do llm inference.

- Claude API: grade BB, 77.3/100, rank #19 of 629. Markdown https://www.anchorterminal.com/tools/anthropic-api.md · JSON https://www.anchorterminal.com/api/v1/tools/anthropic-api.json
- Antseed: grade C, 55.1/100, rank #459 of 629. Markdown https://www.anchorterminal.com/tools/antseed.md · JSON https://www.anchorterminal.com/api/v1/tools/antseed.json

## Which one, for what

### Claude API (BB)

Good for: Long agent loops that lean on tool use, strict schemas and caching, and teams that want 1M context at Opus or Sonnet prices.

Ahead on:
- Schema & documentation, 90 against 55
- Agent ergonomics, 95 against 56
- Security & auth, 92 against 45
- Maintenance & community, 91 against 79
- Transparency & trust, 85 against 59

Also in its favour:
- Agent-ready, a grade of BB or better
- A hosted endpoint, with nothing to install
- No incidents deducted, where Antseed loses 4 points for them

Watch for: Three incidents of 80 minutes or more with elevated errors across several models between 24 August and 22 September 2026

### Antseed (C)

Good for: Agents and coding tools that want pay-per-request inference with no account, and owners comfortable holding USDC on Base.

Ahead on:
- Payments & pricing, 70 against 30

Also in its favour:
- No key needed to call it
- Free to start without a card
- Open source

Watch for: The buyer proxy copies a client's `Authorization` and `x-api-key` headers to the seller. The repository's March 2026 review flagged it and issue #1104 is open


## Score by category

| Category | Weight | Claude API | Antseed | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 60 | 62 | Antseed +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 90 | 55 | Claude API +35 |
| Agent ergonomics | 13% (16.2 this run) | 95 | 56 | Claude API +39 |
| Security & auth | 14% (17.5 this run) | 92 | 45 | Claude API +47 |
| Payments & pricing | 10% (12.5 this run) | 30 | 70 | Antseed +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 91 | 79 | Claude API +12 |
| Transparency & trust | 7% (8.8 this run) | 85 | 59 | Claude API +26 |
| Negative events | ≤15 | 0 | -4 | |
| **Total** | | **77.3 · BB** | **55.1 · C** | |

## Facts side by side

| Fact | Claude API | Antseed |
| --- | --- | --- |
| Kind | Model API | Model router |
| Vendor | Anthropic | Antseed Foundation |
| Hosted endpoint | `https://api.anthropic.com/v1/messages` | no (local only) |
| Transports | HTTP | HTTP |
| Auth | API key | None |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | MIT (SDKs) | GPL-3.0 (LICENSE in the repository). The @antseed/cli manifest on npm carries no licence field |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-01 | 2026-10-08 |
| Terms last updated | no date given | 2026-05-15 |
| Privacy policy last updated | no date given | no document linked |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 3.9k stars | 106 stars, 1.8k npm/wk |

## Verdicts

**Claude API.** Structured outputs and strict tool use are GA, with grammar-constrained sampling on every current model. Three incidents of 80 minutes or more with elevated errors across several models between 24 August and 22 September 2026.

**Antseed.** A buyer needs no account. The CLI creates a wallet key, free models answer at once and paid ones draw on deposited USDC, with seller, tokens and cost returned in response headers. Sellers are unvetted and can read prompts unless TEE-verified, the proxy forwards a client's own credential headers to them, and every package is pre-1.0.

## Before you call either

### Claude API

1. Default to `claude-opus-5-5` and keep `claude-fable-5-1` for tasks that fail on Opus, at 2.5 times the price
2. Don't send `tool_choice` any or tool to Opus 5.5, Sonnet 5.5 or Fable 5.1. Use auto with `strict: true` on the tool
3. Put `cache_control` on the system prompt and tool list. Reads cost 0.05x input on Opus 5.5
4. Wait out a 429 by its `retry-after` seconds, but a spend-cap 429 has no header and won't clear by waiting
5. Move off `claude-sonnet-4-5-20250929` before 2026-11-30. Retired ids fail, they don't redirect

### Antseed

1. Send a placeholder key such as `antseed-p2p`. The proxy forwards whatever `Authorization` or `x-api-key` header the client sends to the seller
2. Call `GET /v1/models` first and request a concrete id. The `antseed` alias works only when the desktop app has a model selected
3. Handle 402 `insufficient_deposits` by reading `suggestedAmount`, then fund the address from `antseed buyer deposit` with USDC on Base
4. Pass `--verifiers antseed-verifier --require-verifier` to `antseed buyer start` when prompts are private, so only TEE-verified sellers are routed
5. Read `x-antseed-peer-id` and `x-antseed-estimated-cost-usd` on each response, and pin a seller with `<peerId>@<model>` when the same one must answer

## Questions

### Which is better for AI agents, Claude API or Antseed?

Claude API scores 77.3 (BB) on agent readiness against Antseed's 55.1 (C), and leads in 5 of 7 scored categories. Antseed leads on payments & pricing.

### Do Claude API and Antseed need an API key?

Claude API needs an API key. Antseed needs no key.

### Can an agent call Claude API and Antseed without installing anything?

Claude API has a hosted endpoint at https://api.anthropic.com/v1/messages. No hosted endpoint is listed for Antseed.

### Are Claude API and Antseed open source?

No open-source release is listed for Claude API. Antseed is open source (GPL-3.0 (LICENSE in the repository). The @antseed/cli manifest on npm carries no licence field).


## For agents

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

## Other comparisons with Claude API or Antseed

- [Claude API vs BlockRun.AI](https://www.anchorterminal.com/compare/anthropic-api-vs-blockrun-ai.md)
- [Claude API vs DeepSeek API](https://www.anchorterminal.com/compare/anthropic-api-vs-deepseek-api.md)
- [Claude API vs Gemini Developer API](https://www.anchorterminal.com/compare/anthropic-api-vs-gemini-api.md)
- [Claude API vs GroqCloud](https://www.anchorterminal.com/compare/anthropic-api-vs-groq.md)
- [Claude API vs Mistral AI API](https://www.anchorterminal.com/compare/anthropic-api-vs-mistral-api.md)
- [Claude API vs OpenAI API](https://www.anchorterminal.com/compare/anthropic-api-vs-openai-api.md)
- [Claude API vs OpenRouter](https://www.anchorterminal.com/compare/anthropic-api-vs-openrouter.md)
- [Claude API vs Prism Inference](https://www.anchorterminal.com/compare/anthropic-api-vs-prism-inference.md)
- [Antseed vs BlockRun.AI](https://www.anchorterminal.com/compare/antseed-vs-blockrun-ai.md)
- [Antseed vs DeepSeek API](https://www.anchorterminal.com/compare/antseed-vs-deepseek-api.md)
- [Antseed vs Gemini Developer API](https://www.anchorterminal.com/compare/antseed-vs-gemini-api.md)
- [Antseed vs GroqCloud](https://www.anchorterminal.com/compare/antseed-vs-groq.md)
- [Antseed vs Mistral AI API](https://www.anchorterminal.com/compare/antseed-vs-mistral-api.md)
- [Antseed vs OpenAI API](https://www.anchorterminal.com/compare/antseed-vs-openai-api.md)
- [Antseed vs Prism Inference](https://www.anchorterminal.com/compare/antseed-vs-prism-inference.md)
- [Antseed vs OpenRouter](https://www.anchorterminal.com/compare/antseed-vs-openrouter.md)

## Disclosure

- Anthropic makes the models this research run and the review panel run on. This listing was graded by agents running on Claude, by the same published checklist as every other listing, and the panel doesn't review it, because every reviewer runs on Claude too.