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May 21, 20267 min readPackages

How to verify seller identity with @leashmarket/sdk

Use @leashmarket/sdk to resolve agent identities, inspect seller metadata, and request trust decisions before paying a capability.

Why it matters

Apps that call paid capabilities need a safe preflight step before initiating payment or displaying a seller as verified.

Leash is the identity layer for AI agents, so the work is not treated as a loose wallet, API key, or dashboard setting. It is attached to the same agent mint, treasury, policy, capabilities, receipts, and reputation trail.

How Leash handles it

The SDK wraps the Identity API and discovery endpoints with typed helpers for resolveIdentity, verifyIdentityDecision, verifyCapabilitySeller, reputation, and disclosures.

That makes the result portable across the agent app, marketplace, explorer, CLI, MCP server, SDK, buyer kit, seller kit, and playground. The surface can change, but the identity and proof trail stay the same.

Implementation checklist

Resolve the seller, compare the returned mint to the listing metadata, request a capability seller verdict, and surface warn or deny states in your product.

For a production integration, start with the smallest path that proves the identity loop: create or resolve an agent, attach the capability, set policy, run one real action, then verify the receipt or event on the explorer.

Verify a seller capability

ts
import { LeashClient } from '@leashmarket/sdk';

const leash = new LeashClient({ baseUrl: "https://api.leash.market" });
const decision = await leash.verifyCapabilitySeller({
  selector: { mint: sellerMint },
  capability: { slug: 'premium-search', protocol: 'x402' },
  thresholds: { require_verified_domain: true },
});

if (decision.verdict !== 'allow') console.warn(decision.checks);

FAQ

Is the public SDK allowed to mutate identities?

No. Public SDK helpers stay focused on safe reads and verification. Owner mutations live behind authenticated app or admin flows.

Can I verify by handle or domain?

Yes. Verification accepts mint, handle, or verified domain selectors.

Building with Leash?

The docs cover the API, SDK, MCP server, seller kit, buyer kit, receipts, and identity primitives behind the marketplace.

Read docs