Signature
Is this certificate actually signed by the tenant's key, and does the caller hold the private key it names?
The platform
One protocol. Every caller.
Sigilex is built around a single primitive — the capability certificate — and three things you can do with it: issue authority to a human, issue it to an AI agent, or hand it to an application that only speaks OpenID Connect. Same certificates, same revocation, same audit trail underneath all three.
The primitive
What a capability certificate actually is
Not a session cookie, not an opaque bearer string. A signed statement: this public key may perform these specific actions, until this specific time.
- Bound to a key, not a session. The certificate names the holder's public key. Without the matching private key — which never leaves the device — a stolen certificate is inert.
- Scoped, not all-or-nothing. A certificate names the specific actions it authorizes. An agent given access to one tool cannot use it to reach another.
- Short-lived by default. A certificate that leaks stops mattering on its own within a bounded window — no incident response required for it to become worthless.
- Delegable, and the delegation is recorded. A human can grant a narrower certificate to an agent acting on their behalf; the chain from the human's authority to the agent's action is provable, not asserted.
holder device pubkey (P-256)
scope tools:invoice.read
scope tools:invoice.export
expires in 4m 12s
delegated by a1e9…04bf (human)
signature valid
Enforcement
Checked on every call — not once at login.
The gateway sits in front of whatever you're protecting and verifies three things on every single request before it's allowed through, then fails closed on anything it can't confirm.
Freshness
Has it expired, and is it inside the freshness lease that keeps a gateway from acting on stale revocation state?
Revocation
Has this certificate, or anything above it in the delegation chain, been killed since it was issued?
Any one of those failing is a denial — never a fallback to "allow and log." The decision is written to the audit trail either way.
Three surfaces, one protocol
Where you actually put it to work.
Sigilex Identity Mesh
Certificate issuance, human and service delegation, per-call gateway verification, and the client-verifiable audit trail. The admin console for the people who run it — members, roles, key rotation, revocation, and the fleet of enforcement gateways, all in one place.
Sigilex for MCP
Put your Model Context Protocol tool servers behind a Sigilex gateway. An agent gets a certificate scoped to specific tools and a short lifetime instead of a shared API key — and because enforcement is per-call, killing one agent's authority never touches another's, mid-session.
Sigilex SSO
A standards-compliant OpenID Connect provider on top of the same certificate core. Applications that only know how to talk OIDC authenticate against Sigilex without any awareness that capability certificates exist underneath.
Get started
See it against your own use case.
We'll walk through how certificate scoping maps to whatever you're trying to protect — an internal API, an MCP tool server, or an application that needs SSO.