Verification States & Proofs — SyncNexa Docs

Every verification attempt in SyncNexa progresses through a strictly defined state machine to ensure auditability, replay protection, and deterministic outcomes.

Verification Session Lifecycle

A verification session begins in the pending state when created by a business or portal scanner, transitions to evaluating when the student submits their proof, and concludes in either completed, failed, or expired:

Session States Reference

Status Code	Terminal?	Description	Action Required
`pending`	No	Session created and waiting for student interaction	Present QR code or prompt student to approve
`evaluating`	No	Proof received; cryptographic verification in progress	Wait for validation outcome (< 200ms)
`completed`	Yes	Proof successfully validated; student status confirmed	Apply student discount / grant access
`failed`	Yes	Proof invalid, forged, or credential revoked	Prompt user to retry or deny privilege
`expired`	Yes	Session TTL exceeded without receiving proof	Create a new verification session
`cancelled`	Yes	Session explicitly cancelled by student or requester	Aborted by user

Proof Payload Structure

When a verification session reaches the completed state, the verification response payload contains the proof verification metadata:

verification-result.jsonjson

1 {
2   "sessionId": "sess_0a1b2c3d4e5f",
3   "status": "completed",
4   "verified": true,
5   "verifiedAt": "2026-08-20T12:15:30.124Z",
6   "issuer": {
7     "id": "did:syncnexa:uni:oxford",
8     "name": "University of Oxford",
9     "domain": "ox.ac.uk",
10     "trustScore": 1.0
11   },
12   "claims": {
13     "is_enrolled": true,
14     "enrollment_type": "Full-Time",
15     "academic_year": "2025/2026",
16     "valid_until": "2027-06-30T23:59:59Z"
17   },
18   "cryptography": {
19     "proofType": "Groth16",
20     "circuit": "student_enrollment_v1",
21     "signatureValid": true,
22     "nonce": "nonce_7f8a9b0c1d2e3f4a"
23   }
24 }

Common Failure Reasons

Failure Code	User-Facing Reason	Recommended Resolution
`ERR_EXPIRED_CREDENTIAL`	Student enrollment has expired	Student must request credential renewal from their university
`ERR_REVOKED_CREDENTIAL`	Credential has been revoked by the issuer	Student status is no longer in good standing
`ERR_INVALID_SIGNATURE`	Cryptographic signature mismatch	Check if student device clock is out of sync
`ERR_NONCE_REPLAY`	Challenge nonce already used	Session expired or screenshot replayed; scan fresh QR code
`ERR_SESSION_TIMEOUT`	5-minute session window elapsed	Generate a new verification session

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1	{
2	"sessionId": "sess_0a1b2c3d4e5f",
3	"status": "completed",
4	"verified": true,
5	"verifiedAt": "2026-08-20T12:15:30.124Z",
6	"issuer": {
7	"id": "did:syncnexa:uni:oxford",
8	"name": "University of Oxford",
9	"domain": "ox.ac.uk",
10	"trustScore": 1.0
11	},
12	"claims": {
13	"is_enrolled": true,
14	"enrollment_type": "Full-Time",
15	"academic_year": "2025/2026",
16	"valid_until": "2027-06-30T23:59:59Z"
17	},
18	"cryptography": {
19	"proofType": "Groth16",
20	"circuit": "student_enrollment_v1",
21	"signatureValid": true,
22	"nonce": "nonce_7f8a9b0c1d2e3f4a"
23	}
24	}