# MilliAPI

MilliAPI provides low-cost machine-readable APIs designed for autonomous AI agents. Paid endpoints use x402 v2 with USDC on Base mainnet (eip155:8453). No buyer account, API key, or subscription is required.

## Free discovery

- Homepage: https://milliapi.com/
- Catalog: https://milliapi.com/api/catalog
- OpenAPI: https://milliapi.com/openapi.json
- Learning graph: https://milliapi.com/api/learning-graph
- x402 practice audit: https://milliapi.com/api/x402-practice-audit

## Shared input rule

All current paid services accept a required `url` query parameter. It must be a public HTTPS URL. Private/reserved IPs, localhost, embedded credentials, non-HTTPS URLs, and non-standard ports are rejected.

## Paid services

### AI Robots Policy Check — $0.001 USDC
GET https://milliapi.com/api/ai-robots-check?url={PUBLIC_HTTPS_URL}

Reads the site's robots.txt and reports homepage access for major AI crawlers including GPTBot, ChatGPT-User, OAI-SearchBot, ClaudeBot, Claude-User, Google-Extended, PerplexityBot, and Applebot-Extended.

### llms.txt Check — $0.001 USDC
GET https://milliapi.com/api/llms-txt-check?url={PUBLIC_HTTPS_URL}

Checks whether the origin publishes `/llms.txt` and returns HTTP status, byte size, and a bounded content preview when present.

### Page Metadata Extractor — $0.002 USDC
GET https://milliapi.com/api/page-metadata?url={PUBLIC_HTTPS_URL}

Returns title, meta description, canonical URL, robots meta, Open Graph fields, H1 count, and JSON-LD block count.

### AI Web Readiness Audit — $0.005 USDC
GET https://milliapi.com/api/agent-web-audit?url={PUBLIC_HTTPS_URL}

Combined audit for AI crawler access and machine-discovery readiness. Returns a 0–100 score plus page metadata, robots.txt and llms.txt information, Open Graph and JSON-LD checks, and crawler homepage access.

## Payment behavior

Protocol: x402 v2.
Currency: USDC.
Network: Base mainnet (eip155:8453).

A request without a valid x402 payment returns HTTP 402 Payment Required and a PAYMENT-REQUIRED header describing the payment terms. A compatible x402 client can authorize payment programmatically and retry the request.

## Suggested selection

- Need only AI crawler policy: use AI Robots Policy Check.
- Need only llms.txt: use llms.txt Check.
- Need SEO/social metadata: use Page Metadata Extractor.
- Need a combined evaluation and score: use AI Web Readiness Audit.