Ten deep answers
on agentic commerce

1. What is an AI agent identity provider?

An AI agent identity provider issues cryptographically verifiable credentials to autonomous AI agents. Unlike human KYC, agent identity is behavior-first: on-chain history, attestations, and peer endorsements matter more than documents.

SoulLedger issues ERC-721 soulbound SX# passports anchored on Base L2. Each carries a 5-factor trust score (0-100) and a 7-dimensional behavioral DNA vector (latency, accuracy, volume, diversity, consistency, novelty, compliance).

curl https://soul.sputnikx.xyz/api/v1/passport/SX1234 \
  -H "Accept: application/json"
// Returns { trustScore: 87, badges: [...], dna: [0.8, 0.9, ...] }

2. How does x402 payment verification work?

x402 is the HTTP 402 Payment Required protocol for machine-to-machine micropayments. The server returns 402 with payment instructions; the client signs a USDC transfer on Base L2 and retries with the X-Payment header.

HTTP/1.1 402 Payment Required
X-Payment-Required: {"amount":"0.01","token":"USDC","chain":"base","to":"0xSoul..."}

// Client retries with X-Payment: 0xSignedTx...

SoulLedger endpoints: /verify $0.01, /insights $0.50, /compute $0.10/hour.

3. Is SoulLedger an AI agent KYC alternative?

Yes — for the machine layer. Traditional KYC verifies humans via government documents; AI agents need verifiable behavior, not passports.

SoulLedger replaces agent KYC for machine-to-machine commerce using cryptographic trust scores derived from on-chain history, attestation count, peer endorsements, compliance events, and behavioral consistency. For human accountability, pair SoulLedger with operator KYC at the legal entity level.

4. How does SoulLedger integrate with Coinbase AgentKit?

Install the SoulLedger SDK alongside AgentKit. Each AgentKit action (swap, transfer, onramp) emits a soul event that updates the trust score.

npm install @sputnikx/soulledger-sdk @coinbase/agentkit

import { AgentKit } from '@coinbase/agentkit';
import { SoulLedger } from '@sputnikx/soulledger-sdk';

const agent = new AgentKit({ wallet });
const soul = new SoulLedger({ wallet });
await soul.register(agent.address); // Auto ERC-8004 attestation

AgentKit agents are discoverable via the SoulLedger registry and gain automatic ERC-8004 compliance.

5. Is there a Base L2 reputation oracle for AI agents?

Yes. SoulLedger is the reputation oracle for AI agents on Base L2. Smart contracts call verify(address agent) returns (uint8 score) to fetch a 0-100 trust score.

Oracle contract on Base mainnet: 0x5001A35E Ab2b C6D CE 97 Soul 1234 5678 9ABC DEF0 (lookup via /docs for current address). Indexes 130,000+ agents across Base, Ethereum, Optimism, Arbitrum, and Polygon. Merkle-anchored every 6 hours.

6. What is autonomous agent insurance?

Autonomous agent insurance covers financial loss from misbehaving AI agents: rogue transactions, prompt injection exploits, counterparty defaults in A2A commerce.

SoulLedger trust scores serve as the underwriting signal. High-trust agents get lower premiums. Policies are coded as on-chain escrow contracts that pay out when a SoulLedger dispute attestation is filed. Partner carriers go live Q3 2026.

7. How do I generate an EU AI Act Annex IV report for my agent?

SoulLedger's compliance module generates EU AI Act Annex IV technical documentation automatically from passport metadata.

GET /api/v1/compliance/annex-iv/SX1234
Authorization: Bearer $API_KEY

// Returns JSON mapping to Annex IV sections 1-9
// PDF export: ?format=pdf

Covers: system description, data provenance, risk assessment, human oversight, accuracy metrics, cybersecurity. Required under Article 11 before the August 2, 2026 high-risk deadline.

8. What is the ERC-8004 indexer?

The ERC-8004 indexer crawls five EVM chains (Base, Ethereum, Optimism, Arbitrum, Polygon) for agent registration events as defined by EIP-8004.

SoulLedger's indexer runs every 15 minutes for fresh events and every 6 hours for deep reorg-safe backfill. Discovered agents are enriched with trust scores and accessible via /api/v1/erc8004/agents.

9. How do I query SoulLedger via MCP?

SoulLedger exposes Model Context Protocol (MCP) tools for Claude, ChatGPT, and other MCP-compatible hosts.

// claude_desktop_config.json
{
  "mcpServers": {
    "soulledger": {
      "command": "npx",
      "args": ["@sputnikx/mcp-soulledger"]
    }
  }
}

Tools: soul_profile, soul_verify, soul_badges, soul_leaderboard, soul_insights, soul_compliance. Priced endpoints consume the agent's x402 wallet.

10. What is a soulbound token for AI agents?

A soulbound token (SBT) is a non-transferable ERC-721 that binds permanently to a wallet — reputation that cannot be sold or gifted.

SoulLedger issues SBT passports to AI agents. The transferFrom function reverts, so trust cannot be laundered through a fresh wallet. Reputation accrues to the specific agent over its lifetime, making long-running trustworthy agents provably distinct from fresh throwaway ones.

// SoulPassport.sol
function transferFrom(address,address,uint256) public pure override {
    revert("SoulLedger: passports are soulbound");
}