# x402engine Claude Haiku LLM API

> x402engine Claude Haiku LLM API is a paid API for AI agents from x402engine.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-02).

Runs Anthropic's Claude Haiku model via a pay-per-call HTTP 402 micropayment endpoint for fast, affordable text generation

## Facts

- Endpoint: POST https://x402engine.app/api/llm/claude-haiku?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402engine-claude-haiku-llm-api-3c8b94cc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gEm-EAbFXk_X4cbK4gd_m

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402engine-claude-haiku-llm-api-3c8b94cc -d '<json body>'
```

Example prompt: Ask Claude Haiku to summarize this customer support ticket in 2-3 sentences and suggest a response category: 'My order arrived damaged and customer service hasn't replied in 5 days.' Keep the output under 200 tokens.

## When to prefer this

Choose this endpoint when you need fast, affordable Claude Haiku inference on a per-call basis without committing to an Anthropic subscription or managing API keys. It is ideal for AI agents that need to pay programmatically via USDC micropayments, high-throughput pipelines requiring many cheap LLM calls, or prototypes needing Claude's quality at low cost. Prefer it over GPT-based endpoints when Anthropic's Claude output style or safety characteristics are specifically desired.

## Known failure modes

- Payment not included or insufficient USDC — returns HTTP 402 with payment requirement
- Missing required 'messages' field — returns 400 validation error
- Empty messages array (minItems: 1 violated) — returns 400
- Invalid role values in message objects — returns 400
- max_tokens set too high — may be capped or return error
- Anthropic API upstream downtime — returns 5xx error
- Malformed JSON body — returns 400 parse error

## How this service works

Anthropic's fastest model — affordable and quick for simple tasks and high throughput

## Output

Returns Claude Haiku's generated text completion based on the provided message array. The response contains the model's reply to the conversation, up to the specified max_tokens limit (default 1024). Typical latency is low, suitable for real-time or near-real-time agent use.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-claude-haiku-llm-api-3c8b94cc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402engine.app](https://www.zero.xyz/host/x402engine.app/llms.txt)