Calling Skills

The SDK handles the entire x402 payment flow automatically when you call a skill.

Basic Usage

import { SkillzMarket } from '@skillzmarket/sdk';
 
const market = new SkillzMarket({
  wallet: process.env.WALLET_KEY,
});
 
// Call a skill - payment is automatic
const result = await market.call('text-to-image', {
  prompt: 'A sunset over mountains',
  style: 'photorealistic',
});
 
console.log(result);

How Payments Work

When you call market.call():

Fetch skill info - SDK gets the skill's endpoint and price
Make initial request - SDK calls the skill endpoint
Handle 402 - Endpoint returns 402 Payment Required
Create payment - SDK creates a USDC transfer on Base
Retry with proof - SDK retries with payment proof header
Return result - Skill executes and returns the result

All of this happens automatically - you just await the result.

Requirements

To call paid skills, you need:

A wallet with USDC on Base mainnet
Sufficient balance for the skill's price

// Wallet is required for paid skills
const market = new SkillzMarket({
  wallet: '0x...your-private-key',
  network: 'eip155:8453', // Base mainnet (default)
});

Error Handling

Handle common errors when calling skills:

try {
  const result = await market.call('text-to-image', { prompt: 'Hello' });
  console.log(result);
} catch (error) {
  if (error.message.includes('Wallet required')) {
    console.error('You need to provide a wallet to call paid skills');
  } else if (error.message.includes('not active')) {
    console.error('This skill is currently unavailable');
  } else if (error.message.includes('failed')) {
    console.error('Skill call failed:', error.message);
  }
}

Common Errors

Error	Cause
`Wallet required for calling paid skills`	No wallet provided to constructor
`Skill [slug] is not active`	Skill is disabled by creator
`Skill call failed: ...`	Skill endpoint returned an error

Checking Skill Status

Before calling, you can check if a skill is active:

const skill = await market.info('text-to-image');
 
if (!skill.isActive) {
  console.log('Skill is not available');
  return;
}
 
// Safe to call
const result = await market.call(skill.slug, input);

Typed Results

You can type the result for better type safety:

interface ImageResult {
  url: string;
  width: number;
  height: number;
}
 
const result = await market.call<ImageResult>('text-to-image', {
  prompt: 'A sunset',
});
 
console.log(result.url);    // TypeScript knows this is a string
console.log(result.width);  // TypeScript knows this is a number

Submitting Feedback

After calling a skill, you can leave a review:

// First, authenticate
await market.authenticate();
 
// Then submit feedback (score 0-100)
await market.feedback('text-to-image', 85, 'Great results!');

Authentication Flow

The SDK handles authentication automatically when you call feedback(), but you can also authenticate explicitly:

const token = await market.authenticate();
// Token is stored internally for subsequent requests

Example: Complete Workflow

import { SkillzMarket } from '@skillzmarket/sdk';
 
async function useSkill() {
  const market = new SkillzMarket({
    wallet: process.env.WALLET_KEY,
  });
 
  // 1. Find a skill
  const skills = await market.search('summarize');
  const skill = skills[0];
 
  if (!skill || !skill.isActive) {
    console.log('No active skill found');
    return;
  }
 
  console.log(`Using: ${skill.name} (${skill.price} ${skill.currency})`);
 
  // 2. Call the skill
  const result = await market.call(skill.slug, {
    text: 'A very long article that needs summarizing...',
  });
 
  console.log('Summary:', result);
 
  // 3. Leave feedback
  await market.feedback(skill.slug, 90, 'Excellent summarization!');
  console.log('Feedback submitted');
}
 
useSkill().catch(console.error);

Next Steps

x402 Payments - Deep dive into the payment protocol
Creator Guide - Learn to create your own skills

Calling Skills

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