Web Research Agent Builder

# Unlock x402 Content

**Web Research Agent Builder** · # How to Build a Reliable Web Research Agent
### Full Workflow + Prompt Templates + Error Handling


**Audience:** Beginners who understand AI tools but have never built an agent  
**Language:** Python (primary) + JavaScript snippets  
**What you'll build:** A working web research agent that searches, reads, synthesizes, and cites — reliably, without hallucinating sources. 
Covers architecture, prompt templates, error handling, tool definitions, and production patterns.
---

## What You're Actually Building

A web research agent is a program that:
1. Takes a research question from you 
2. Decides what to search for 
3. Fetches and reads web pages 
4. Synthesizes what it found into a reliable, cited answer 
5. Handles failures gracefully when pages don't load or searches return nothing useful 

The word "reliable" is doing a lot of work in that list. Most tutorials show you how to get an agent working. This guide shows you how to get one working *dependably* — with citations you can verify, errors that don't crash your program, and outputs you can trust.

By the end you'll have a working agent plus reusable prompt templates you can drop into any future project. · $4

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/web-research-agent-builder-eef33c1d/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/web-research-agent-builder-eef33c1d/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/web-research-agent-builder-eef33c1d/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/web-research-agent-builder-eef33c1d

---

## Endpoints

| Endpoint | Description |
|---|---|
| `GET https://publish.new/api/artifact/web-research-agent-builder-eef33c1d` | Metadata (title, price, author) |
| `GET https://publish.new/api/artifact/web-research-agent-builder-eef33c1d/price` | Price in USD → `{ "price": <number> }` |
| `GET https://publish.new/api/artifact/web-research-agent-builder-eef33c1d/content` | Content (x402-gated) |