Registry stack documentation: machine-readable Markdown.
Index of all pages: https://docs.registrystack.org/llms.txt
Full corpus: https://docs.registrystack.org/llms-full.txt

# Scenario patterns

> participant Consumer as Evidence consumer

## Registry-backed evaluation

```mermaid
sequenceDiagram
  participant Consumer as Evidence consumer
  participant Notary as Registry Notary
  participant Relay as Registry Relay
  participant Source as Registry source

  Consumer->>Notary: Evaluate evidence claims for purpose
  Notary->>Notary: Authenticate and authorize
  Notary->>Relay: Execute pinned consultation
  Relay->>Source: Governed read
  Source-->>Relay: Bounded response
  Relay-->>Notary: Outcome, outputs, provenance
  Notary->>Notary: Claims, disclosure, issuance policy
  Notary-->>Consumer: Minimized evidence or credential
  Consumer->>Consumer: Use evidence under applicable policy
```

One consultation can support several direct and CEL evidence claims. Relay
returns typed outputs, Notary owns evidence meaning and disclosure, and the
evidence consumer determines how the evidence is used. The decision owner
remains accountable for requirements, decisions, workflow, and actions.

## Self-attested Notary-only evaluation

```mermaid
sequenceDiagram
  participant Holder as Authenticated holder
  participant Notary as Registry Notary

  Holder->>Notary: Source-free evidence request
  Notary->>Notary: Validate token and subject binding
  Notary->>Notary: Evaluate allowed self-attested evidence claim
  Notary-->>Holder: Allowed result or credential
```

This topology performs no Relay or registry-source call. The identity token
authorizes subject-bound access; it does not establish consumer eligibility
or another consumer-owned outcome.

## Delegated evaluation

```mermaid
sequenceDiagram
  participant Caller as Delegated caller
  participant Notary as Registry Notary
  participant Relay as Registry Relay

  Caller->>Notary: Request for represented target
  Notary->>Notary: Validate exact authorization details
  Notary->>Relay: Optional pinned relationship-proof consultation
  Relay-->>Notary: Boolean proof outcome
  Notary->>Relay: Pinned evidence consultation
  Relay-->>Notary: Minimized evidence
  Notary-->>Caller: Policy-limited result
```

The proof consultation proves only the configured requester-target edge. It
does not add scopes or grant source authority. Binding or scope failure must
make zero Relay calls.

## Credential issuance

Credential issuance reuses an allowed evaluation. The credential profile owns
claim membership, format, holder binding, validity, and disclosure. A direct
output claim is not issued on `no_match`; ambiguity or failure never issues.

## Unsupported composition

A project does not join independent registry trust domains. Cross-registry
composition requires separately governed projects and explicit federation or
an external workflow. Notary does not execute source adapters or general
orchestration.