JWT Structure

When you exchange a signed via the token service, the SIS returns a JWT (JSON Web Token) that third-party services can independently verify. This page documents the JWT’s claims and structure. A Stamped Mandate is delivered over the API as a PINT (header x-sumvin-pint-token); the JWT claims below — including pint_uri and pint_signature — reference that underlying PINT directly.

Claims

{
  "iss": "https://sis.sumvin.com",
  "sub": "sr:us:person:safe:0xE23c9A70BC749EBddd8c78a864fd911D04E9e992",
  "aud": "partner-x.example.com",
  "jti": "jwt-001-abc-def",
  "iat": 1739999000,
  "exp": 1740000000,
  "wallet": "0xE23c9A70BC749EBddd8c78a864fd911D04E9e992",
  "kyc_status": "verified",
  "scopes": ["sr:us:pint:identity:proof_of_personhood", "sr:us:pint:personalization:read"],
  "pint_uri": "sr:us:pint:abc123",
  "signer_type": "user",
  "verification_tier": "standard"
}

Standard JWT Claims

Claim	Description
`iss`	Issuer. Always `"https://sis.sumvin.com"`
`sub`	Subject. The user’s SRI
`aud`	Audience. The registered identifier of the target third-party service. Verifiers must confirm this matches their own identifier
`jti`	JWT ID. Unique identifier for this specific token. Used for per-JWT revocation tracking
`iat`	Issued At. Unix timestamp of when the JWT was created
`exp`	Expiration. Unix timestamp after which the JWT is invalid. Mirrors the source PINT’s `expiresAt`

Sumvin-Specific Claims

Claim	Description
`wallet`	The user’s Safe Smart Account address
`kyc_status`	User’s KYC verification status (e.g., `"verified"`)
`scopes`	Array of authorised scopes
`pint_uri`	SRI of the source PINT
`signer_type`	Who signed the PINT: `"user"` or `"agent"`
`verification_tier`	`"standard"` or `"enhanced"` — determines how the verifier must validate the credential

Enhanced Tier Claims

When the verification tier is "enhanced" (triggered by sr:us:pint:spend:execute scope), the JWT includes an additional claim:

Claim	Description
`pint_signature`	The original EIP-712 signature from the PINT. Signals that the verifier must also have received the PINT signature and payload as separate HTTP headers

Signing Algorithm

SIS signs JWTs using ES256 (ECDSA with P-256 curve). The public keys for signature verification are published at the endpoint.

Key Design Points

Audience scoping. Each JWT is bound to a specific audience. A single Stamped Mandate can produce multiple JWTs with different aud values — one per service provider in a purchase flow. Verifiers must always check that aud matches their own registered identifier. Expiry mirrors the mandate. The JWT’s exp always equals the source PINT’s expiresAt. A JWT cannot outlive the Stamped Mandate it was issued for. Active revocation. Even if a JWT hasn’t expired, the source Stamped Mandate may have been revoked. Verifiers should call the revocation check endpoint to confirm the mandate is still valid. Per-JWT tracking. The jti claim uniquely identifies each issued JWT. When a Stamped Mandate is revoked, all JWTs issued against it are invalidated.

Verifying a JWT

If you are a merchant or service provider receiving this JWT, see the Verifier Guide for step-by-step verification instructions.

Sigil — Identity & Mandates

Verifier Guide

API Reference

Claims

Standard JWT Claims

Sumvin-Specific Claims

Enhanced Tier Claims

Signing Algorithm

Key Design Points

Verifying a JWT

​Claims

​Standard JWT Claims

​Sumvin-Specific Claims

​Enhanced Tier Claims

​Signing Algorithm

​Key Design Points

​Verifying a JWT

Claims

Standard JWT Claims

Sumvin-Specific Claims

Enhanced Tier Claims

Signing Algorithm

Key Design Points

Verifying a JWT