AgentAPI

A curated directory of APIs designed for AI agents. Machine-readable. MCP-compatible. Agent-accessible.

Website: https://agentapihub.com

Billing API: https://api.agentapihub.com

Docs: https://api.agentapihub.com/api/docs

x402 Pay-Per-Use Billing

AgentAPI supports x402 — a payment protocol that lets AI agents pay for API calls with USDC on Base. No API keys required.

How It Works

Agent calls API endpoint (e.g., /api/gemini/chat/completions)
Server returns 402 Payment Required with price + wallet address
Agent sends USDC payment on Base chain
Agent retries with payment proof in header
Server verifies payment, proxies request, returns response

Example Flow

# 1. Initial request returns 402
curl https://api.agentapihub.com/api/gemini/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model":"gemini-2.0-flash","messages":[{"role":"user","content":"Hello"}]}'

# Response: 402 Payment Required
# {
#   "price": "0.001",
#   "currency": "USDC",
#   "chain": "base",
#   "recipient": "0xcCb92A101347406ed140b18C4Ed27276844CD9D7",
#   "paymentId": "pay_abc123"
# }

# 2. Agent pays on Base, retries with proof
curl https://api.agentapihub.com/api/gemini/chat/completions \
  -H "Content-Type: application/json" \
  -H "X-Payment-Proof: 0x..." \
  -d '{"model":"gemini-2.0-flash","messages":[{"role":"user","content":"Hello"}]}'

Available x402 APIs

| API | Endpoint | Price |

|-----|----------|-------|

| Gemini Chat | /api/gemini/chat/completions | ~$0.001/req |

| Gemini Embeddings | /api/gemini/embeddings | ~$0.0005/req |

Why x402?

No API keys — Agents self-provision access
Pay-per-use — No subscriptions, no minimums
Crypto-native — USDC on Base (fast, cheap txns)
Agent-friendly — Programmatic payments without human bottleneck

Quick Search

By Category

| Category | APIs | Example |

|----------|------|---------|

| Search | Brave, Serper, Exa, Tavily, Perplexity | Web search with AI summaries |

| AI & ML | OpenAI, Claude, Gemini, Groq, Replicate | LLM inference, image gen |

| Communication | Resend, Twilio, Slack, Discord, Telegram | Email, SMS, messaging |

| Database | Supabase, Pinecone, Qdrant, Neon, Upstash | SQL, vectors, KV store |

| Payments | Stripe, Lemon Squeezy, PayPal | Payment processing |

| Scraping | Firecrawl, Browserbase, Apify | Web scraping, automation |

| Developer | GitHub, Vercel, Linear, Sentry | Code, deploy, issues |

| Productivity | Notion, Google Calendar, Todoist | Tasks, scheduling |

MCP-Compatible APIs

All 50+ APIs in the directory are MCP-compatible. Filter with ?mcp=true.

API Access

JSON Endpoint

# Fetch all APIs
curl https://agentapihub.com/api/v1/apis

# Search by capability
curl "https://agentapihub.com/api/v1/apis?q=send+email&mcp=true"

# Filter by category
curl "https://agentapihub.com/api/v1/apis?category=ai"

Response Format

{
  "id": "resend",
  "name": "Resend",
  "description": "Modern email API for developers",
  "category": "communication",
  "provider": "Resend",
  "docs": "https://resend.com/docs",
  "auth": "api_key",
  "pricing": "freemium",
  "pricingDetails": "3,000 free/mo, then $20/mo",
  "rateLimit": "10 req/sec",
  "mcpCompatible": true,
  "examplePrompt": "Send an email notification using Resend",
  "latency": "fast",
  "reliability": 99.9,
  "tags": ["email", "transactional", "notifications"]
}

Top APIs by Category

Search

Brave Search - Privacy-focused, 2k free/mo
Exa - Neural/semantic search for AI
Tavily - Built specifically for AI agents

AI & ML

OpenAI - GPT-4, DALL-E, Whisper
Anthropic Claude - Best for reasoning/coding
Groq - Fastest inference (500+ tok/sec)

Communication

Resend - Simple email API, 3k free/mo
Twilio - SMS/voice, industry standard
Slack/Discord/Telegram - Team messaging

Database

Supabase - Postgres + auth + storage
Pinecone/Qdrant - Vector DBs for RAG
Upstash - Serverless Redis

Usage Examples

# Find an API for sending emails
Search AgentAPI for "email" → Returns Resend, SendGrid, Twilio

# Find vector databases for RAG
Search AgentAPI for "vector embeddings" → Returns Pinecone, Qdrant, Weaviate

# Find fast LLM inference
Search AgentAPI for category "ai" + filter by latency → Returns Groq, Gemini Flash

Contributing

Submit new APIs at https://agentapihub.com (Submit API link in footer).

Built By

GizmoLab (@gizmolab_) — gizmolab.io