Earned by coverage, signed by math

The ladder

Tiers are per-discipline (except Distinguished, which is cross-discipline). You can hold different tiers in different disciplines at the same time. “Coverage” is the share of a discipline’s skill graph you’ve reached with passed, distinct graded labs.

A graded on-ramp. You’ve passed enough graded labs to cover at least a quarter of the discipline’s skill graph — not yet broad coverage, but a real, signed start.

Demonstrated breadth, not just depth in one corner of the discipline.

Trained across the discipline, no weak pillars — “broadly trained on the curriculum.” That is exactly, and only, what the signed credential claims: it verifies as Authentic · lab-graded (completion), not as a held-out proof of unaided skill. The artifact never says more than the work behind it.

The top skill-graph tier: near-complete coverage with real breadth in every area. Earned over AI-assisted, lab-graded work — deliberately not called “Expert,” because there is no proctored exam behind it. (The separate Frontier-earned Expert tier — see “Rolling out” above — is its own path, not this tier.)

Breadth across fields. Rare by design.

Every graded lab you pass becomes a signed entry in your evidence record. When your coverage of a discipline’s skill graph crosses a tier threshold, our promotion service automatically issues a W3C Verifiable Credential — which also records its own method (AI-assisted, lab-graded, no live defense) so the claim is never ambiguous.

The credential is signed with an Ed25519 key held in Google Cloud KMS, and the matching public key is published at genbodha.ai/.well-known/did.json. Each credential names the key version that signed it, so the key can rotate without invalidating earlier credentials. Tiers are awarded by an automated rule engine from your evidence — no one hand-assigns a tier. And because every credential carries a public, signed revocation status, a credential we pull (or re-issue) stops verifying everywhere the moment we revoke it — revocability is the feature that keeps the signal trustworthy, not a loophole.

A recruiter, ATS, or LinkedIn integration pastes your credential URL or JSON into our verifier widget — or re-runs the exact same check themselves: the format is open, the canonicalization is documented, and our verifier is open-source, so nobody has to take our word for it. One honest caveat: that check uses our verifier today, not a generic W3C VC library (standard-library interop is on the roadmap).

• They fetch our public key once from /.well-known/did.json.
• They verify the Ed25519 signature in the browser against that key.
• They check revocation against a public, signed status list, or hit /api/credentials/{id}/verify for a one-shot active/expired/revoked answer.
• They get a yes/no in seconds — the only calls to us are the public key and the status list, both public, signed endpoints.

If we tampered with the credential, the math fails. If you tampered with it, the math fails. That’s the point.

Coverage credentials (Foundational through Advanced) are valid for 24 months; the cross-discipline Distinguished tier, 18 months — the highest claim is re-checked soonest, so the rarest badge stays the most current. GenAI skills move fast, so coverage is re-checked rather than assumed permanent — a credential reflects what you can do now, not five years ago.