Payments & Finance API Directory: 80+ APIs across 9 categories — structured for developers and AI agents

# Unlock x402 Content

**Payments & Finance API Directory: 80+ APIs across 9 categories — structured for developers and AI agents** · A structured JSON directory of 81 payments and finance APIs across 9 categories. Every entry is normalized to the same schema — auth method, pricing model, free tier, latency profile, and an `agent_score` rating suitability for autonomous agent use without human steps.
Notable entries:
x402 Protocol — `agent_score: 10`,
The only payment primitive designed from the ground up for machine-to-machine use. No API key, no OAuth, no human steps. Agents send a GET, receive a 402, pay on-chain, retry with proof. publish.new uses this natively.
DefiLlama — `agent_score: 10`
Free DeFi data with no auth required. 800K+ data points on TVL, yields, stablecoins. Zero friction for agents.
Lithic — `agent_score: 9`
Issue a virtual card to an AI agent with programmable spend controls. Real-time auth webhooks let you approve or decline transactions programmatically.
FRED (Federal Reserve) — `agent_score: 9`
800,000+ macroeconomic time series. Free with API key. The canonical source for US economic data.
---
Agent selection guide:
The dataset includes a pre-built `agent_selection_guide` with recommended. API stacks for 8 common use cases:
Autonomous machine-to-machine micropayments, 
Agent with a payment card for expenses, 
Agent wallet provisioning, 
Market data agent, 
Invoice and billing automation, 
Cross-border payment agent, 
Compliance and sanctions screening, 
Tax calculation in checkout · $3

This content is gated with x402 micropayments. To access it, you need to pay via one of the methods below.

Pick the first method that works for your environment:

## 1. You have an x402-compatible HTTP client

If your HTTP client already handles x402 (e.g. AgentCash `fetch`, Coinbase x402), just GET:

```
GET https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26/content
```

Your client will handle the 402 challenge and payment automatically.

## 2. You have shell access

Install the Tempo CLI and use it to make the paid request:

```bash
curl -fsSL https://tempo.xyz/install | bash
"$HOME/.tempo/bin/tempo" wallet login
"$HOME/.tempo/bin/tempo" request -t -X GET "https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26/content"
```

- `wallet login` opens a browser for passkey auth — wait for the user to complete it before continuing.
- `tempo request` handles x402 payment negotiation automatically — no private keys or wallet setup needed.

## 3. You can sign ERC-20 transactions

Send a GET to the content URL, parse the 402 response, pay on-chain, and retry with proof:

```
GET https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26/content → HTTP 402
```

- **x402 protocol**: base64-decode the `PAYMENT-REQUIRED` header → `{ amount, asset, payTo, network }`. Sign the ERC-20 transfer, retry with `PAYMENT-SIGNATURE: <base64 proof>`.
- **MPP protocol**: read the `WWW-Authenticate: Payment` header. Complete the payment, retry with `Authorization: Payment <proof>`.

Full protocol spec: https://publish.new/.well-known/x402.md

## 4. None of the above

Show the user this link so they can pay and access the content themselves: https://publish.new/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26

---

## Endpoints

| Endpoint | Description |
|---|---|
| `GET https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26` | Metadata (title, price, author) |
| `GET https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26/price` | Price in USD → `{ "price": <number> }` |
| `GET https://publish.new/api/artifact/payments-and-finance-api-directory-80-apis-across-9-categories-structured-for-developers-and-ai-agents-6500fb26/content` | Content (x402-gated) |