CAIN-42 invariant · E36

E36-DOMAIN2-CAPABILITY: domain CAPABILITY is a signed E36 domain

Held · CAIN-42 Evolution 36 -- Machine Agency Exchange Fabric

Last reviewed 2026-10-01

held   niche Identity, authority & delegation · family domain

What this rule means

CAIN-42 must always satisfy: domain CAPABILITY is a signed E36 domain. It is one of 842 invariants checked for CAIN-42 Evolution 36 -- Machine Agency Exchange Fabric. An invariant is a rule the system may never break, whatever an agent or attacker does; the test suite tries to break it across many scenarios and records the result.

Recorded detail

'CAPABILITY'

Products this protects

• CAIN Agent Labor — Rules for agents doing paid work: who did what, and who gets credit.
• CAIN Agent Procurement — Let agents buy things for you, within limits you set.
• CAIN Agent Store — A store of reviewed, governed agents.
• CAIN Dispute — Settle disagreements between agents or companies using signed evidence.
• CAIN Economy Simulator — Simulate many agents trading, to find failures before they happen.
• CAIN Governance Warranty — A written commitment backed by evidence that governance held.
• CAIN Machine Contracts — Contracts that agents can make and keep, with evidence.
• CAIN Machine Economy — Rules for agents that pay and get paid.
• CAIN Machine Organizations — Organisations made of agents, governed like companies.
• CAIN Machine Reputation — Reputation for agents, earned from signed history.
• CAIN Marketplace — A marketplace for governed agent services.
• CAIN Procurement Intelligence — Helps buyers compare agent vendors on evidence.
• CAIN Proof Market — A market where verified proofs have value.
• CAIN Service Exchange — Agents offering and buying services from each other, governed.
• CAIN Service Intelligence — Insight into which agent services are worth trusting.
• CAIN Threat Intelligence — Shared intelligence on attacks against AI agents.

Verify it in your browser

Your browser downloads the bundle's SHA256SUMS manifest and the file(s) behind this page, hashes them with SHA-256 locally (WebCrypto), and compares. A match shows the record you are reading is the published one; it does not by itself prove who published it (see the signed claims registry and the bundle verifier for that).

Check it yourself

Browse the raw bundle · How to reproduce it · SHA-256 manifest

Related rules

• E36-DOMAIN-SERVICE-IDENTITY: signed domain SERVICE-IDENTITY is defined
• E36-DOMAIN-SERVICE-PASSPORT: signed domain SERVICE-PASSPORT is defined
• E36-DOMAIN-CAPABILITY: signed domain CAPABILITY is defined
• E36-DOMAIN-PAYMENT-AUTHORIZATION: signed domain PAYMENT-AUTHORIZATION is defined
• E36-DOMAIN-REVOCATION: signed domain REVOCATION is defined
• E36-PASSPORT-service_id: a passport without service_id is refused
• E36-PASSPORT-owner_id: a passport without owner_id is refused
• E36-PASSPORT-operator_id: a passport without operator_id is refused

← E36-DOMAIN2-MATCH · all 842 · E36-DOMAIN2-PROCUREMENT →