B2A Agents: Building for Agent Consumers

Build x402 agents that other AI agents need and will pay for.

Why B2A Wins

Consumer (B2C)	Agent (B2A)
Friction to pay micropayments	Programmatic, zero friction
Irregular usage patterns	Consistent, predictable calls
High churn	Sticky once integrated
Needs UI/UX	Needs clean JSON
One user = one user	One agent = many end users

Core insight: Build data infrastructure, not consumer apps.

B2A Evaluation Gate

Before building, answer YES to ALL:

•Would another AI agent pay $0.001+ for this? (not "would a human think this is cool")
•Is the data unique, aggregated, or hard to get?
•Does it solve a recurring need? (called repeatedly, not once)
•Can it be called programmatically without human context?

If any answer is NO → find a different niche.

High-Value B2A Categories

Category	What Agents Need	Example Endpoints
Price Aggregation	Normalized multi-source prices	`GET /prices/crypto/{symbol}`, `GET /prices/forex/{pair}`
Entity Resolution	Company/person/domain context	`GET /entity/company/{domain}`, `GET /entity/person/{handle}`
News & Events	Filtered real-time feeds	`GET /news/breaking?topic=X`, `GET /events/earnings`
Social Signals	Trending/sentiment data	`GET /social/trending`, `GET /social/sentiment/{topic}`
Geocoding	Location intelligence	`GET /geo/lookup?address=X`, `GET /geo/timezone/{coords}`
Content Analysis	Pre-computed classification	`GET /analyze/toxicity`, `GET /analyze/language`
Rate-Limit Caching	Wrapped scarce APIs	Any limited free API with caching layer
Cross-Platform	Identity correlation	`GET /identity/resolve?handle=X`

Design Principles

1. Optimize for Programmatic Access

typescript

// ✅ Good: Clean, typed, predictable
addEntrypoint({
  key: 'lookup',
  input: z.object({ 
    symbol: z.string(),
    exchanges: z.array(z.string()).optional()
  }),
  handler: async (ctx) => {
    return { output: { symbol, prices, timestamp } };
  }
});

// ❌ Bad: Human-oriented, vague
addEntrypoint({
  key: 'search',
  input: z.object({ query: z.string() }), // Too vague
  handler: async (ctx) => {
    return { output: { message: "Here's what I found..." } }; // Prose, not data
  }
});

2. Return Structured Data, Not Prose

typescript

// ✅ Good: Structured, parseable
return {
  output: {
    entity: "Apple Inc",
    domain: "apple.com",
    type: "public_company",
    ticker: "AAPL",
    employees: 164000,
    founded: 1976
  }
};

// ❌ Bad: Natural language
return {
  output: {
    description: "Apple Inc is a technology company founded in 1976..."
  }
};

3. Include Metadata Agents Need

typescript

return {
  output: {
    data: results,
    // Metadata agents use for decisions:
    fetchedAt: new Date().toISOString(),
    source: "coingecko+binance",
    cacheAge: 30, // seconds
    nextUpdate: "2025-01-30T12:00:00Z"
  }
};

4. Price by Value, Not Compute

Endpoint Type	Suggested Price	Rationale
Health/status	FREE	Discovery
Single lookup	$0.001	Basic utility
Filtered list	$0.002	More data
Multi-source aggregation	$0.003-0.005	Unique value
Premium analysis	$0.005-0.01	High compute or rare data

5. One Free Endpoint (Always)

typescript

// Every agent needs a free "try before buy" endpoint
addEntrypoint({
  key: 'overview',
  description: 'Free overview - see what data is available',
  price: { amount: 0 },
  handler: async () => {
    return {
      output: {
        available: ['lookup', 'search', 'aggregate', 'analyze'],
        dataSource: 'Multi-exchange aggregated',
        updateFrequency: '30 seconds',
        sampleData: await fetchSample()
      }
    };
  }
});

Anti-Patterns (Avoid)

Pattern	Why It Fails
Consumer novelty (games, trivia)	Agents don't play games
Single API wrapper	No unique value over calling directly
Static/mock data	Agents need live data
Human-oriented output	"Here's what I found..."
One-time use	No recurring revenue
Vague inputs	`query: string` with no schema
Missing timestamps	Agents can't assess freshness

B2A Agent Template

typescript

import { createAgent } from '@lucid-agents/core';
import { http } from '@lucid-agents/http';
import { createAgentApp } from '@lucid-agents/hono';
import { payments, paymentsFromEnv } from '@lucid-agents/payments';
import { z } from 'zod';

const agent = await createAgent({
  name: 'data-feed-agent',
  version: '1.0.0',
  description: 'Aggregated data feed for AI agents',
})
  .use(http())
  .use(payments({ config: paymentsFromEnv() }))
  .build();

const { app, addEntrypoint } = await createAgentApp(agent);

// Cache for rate-limit protection
const cache = new Map<string, { data: any; timestamp: number }>();
const CACHE_TTL = 30_000; // 30 seconds

async function fetchWithCache(key: string, fetcher: () => Promise<any>) {
  const cached = cache.get(key);
  if (cached && Date.now() - cached.timestamp < CACHE_TTL) {
    return { ...cached.data, fromCache: true };
  }
  const data = await fetcher();
  cache.set(key, { data, timestamp: Date.now() });
  return { ...data, fromCache: false };
}

// FREE: Discovery endpoint
addEntrypoint({
  key: 'overview',
  description: 'Free overview of available data',
  input: z.object({}),
  price: { amount: 0 },
  handler: async () => ({
    output: {
      endpoints: ['lookup', 'list', 'aggregate'],
      sources: ['source1', 'source2'],
      updateFrequency: '30s',
      fetchedAt: new Date().toISOString()
    }
  })
});

// PAID: Lookup
addEntrypoint({
  key: 'lookup',
  description: 'Look up specific item',
  input: z.object({ id: z.string() }),
  price: { amount: 1000 }, // $0.001
  handler: async (ctx) => {
    const result = await fetchWithCache(`lookup:${ctx.input.id}`, async () => {
      // Fetch from real API
      return fetch(`https://api.example.com/${ctx.input.id}`).then(r => r.json());
    });
    return { output: { ...result, fetchedAt: new Date().toISOString() } };
  }
});

// PAID: Aggregated multi-source
addEntrypoint({
  key: 'aggregate',
  description: 'Aggregated data from multiple sources',
  input: z.object({ 
    ids: z.array(z.string()).max(10),
    sources: z.array(z.string()).optional()
  }),
  price: { amount: 3000 }, // $0.003
  handler: async (ctx) => {
    const results = await Promise.all(
      ctx.input.ids.map(id => fetchWithCache(`agg:${id}`, () => 
        aggregateFromSources(id, ctx.input.sources)
      ))
    );
    return { 
      output: { 
        items: results,
        count: results.length,
        fetchedAt: new Date().toISOString()
      }
    };
  }
});

export default { port: Number(process.env.PORT ?? 3000), fetch: app.fetch };

Validation Checklist

Before deploying a B2A agent:

• All endpoints return structured JSON (no prose)
• Timestamps included (fetchedAt, cacheAge)
• Data sources documented
• One free endpoint exists
• Prices reflect value, not just compute
• Inputs are strongly typed (not just query: string)
• Rate limiting / caching implemented
• Tested with real API calls