1 · System architecture
How a governed AI action moves through the control plane and produces
tamper-evident decision evidence. Conceptual component view.
flowchart LR
client([Client · AI agent · integration]):::ext
edge[Secure ingress
TLS · rate limiting]:::edge subgraph plane["AI Control Plane"] api["Control-plane API"]:::core policy["Policy decision engine"]:::svc gw["Model gateway"]:::svc idp["Identity & access"]:::svc sec["Secrets & signing"]:::svc end evid[("Decision-evidence store
append-only · hash-chained · signed")]:::db models[("AI model providers")]:::ext client --> edge --> api api -->|authorize| policy api -->|model call| gw --> models api -->|authenticate| idp api -->|signing keys| sec api -->|record decision| evid classDef ext fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef edge fill:#e7eefb,stroke:#7fa1d8,color:#0B1F3A; classDef core fill:#e3f1ea,stroke:#5fae87,color:#0B1F3A; classDef svc fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef db fill:#f6ecf3,stroke:#c79ab8,color:#0B1F3A;
TLS · rate limiting]:::edge subgraph plane["AI Control Plane"] api["Control-plane API"]:::core policy["Policy decision engine"]:::svc gw["Model gateway"]:::svc idp["Identity & access"]:::svc sec["Secrets & signing"]:::svc end evid[("Decision-evidence store
append-only · hash-chained · signed")]:::db models[("AI model providers")]:::ext client --> edge --> api api -->|authorize| policy api -->|model call| gw --> models api -->|authenticate| idp api -->|signing keys| sec api -->|record decision| evid classDef ext fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef edge fill:#e7eefb,stroke:#7fa1d8,color:#0B1F3A; classDef core fill:#e3f1ea,stroke:#5fae87,color:#0B1F3A; classDef svc fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef db fill:#f6ecf3,stroke:#c79ab8,color:#0B1F3A;
2 · Governed decision & evidence chain
Every governed AI action is policy-checked first, then recorded as
tamper-evident, signed evidence with an audit trail — before the outcome is returned.
sequenceDiagram
autonumber
participant Caller as User / AI agent
participant ACP as AI Control Plane
participant Policy as Policy engine
participant Evidence as Decision evidence
(signed · hash-chained) participant Audit as Audit trail Caller->>ACP: Requested AI action ACP->>Policy: Evaluate tenant-scoped policy Policy-->>ACP: Allow · deny · approval-required ACP->>Evidence: Record tamper-evident decision evidence ACP->>Audit: Append audit event ACP-->>Caller: Outcome + evidence reference
(signed · hash-chained) participant Audit as Audit trail Caller->>ACP: Requested AI action ACP->>Policy: Evaluate tenant-scoped policy Policy-->>ACP: Allow · deny · approval-required ACP->>Evidence: Record tamper-evident decision evidence ACP->>Audit: Append audit event ACP-->>Caller: Outcome + evidence reference
Property: evidence is append-only, hash-chained, and signed,
so any later alteration is detectable on review.
3 · Proof pack & regulatory-review boundary
How governed evidence rolls up into a repeatable, signed proof pack that a
regulated firm and its reviewers can assess — and what stays the firm's own responsibility.
flowchart LR
gov["Governed AI decisions
+ decision evidence"]:::core proof["Signed proof-pack manifest
repeatable release gate"]:::svc reg["FCA/PRA evidence-pack register"]:::svc review["Firm review
risk · compliance · audit · accountable owner"]:::svc dd([Buyer diligence decision]):::ext gov --> proof --> reg --> review --> dd reg -. boundary .-> b1["Technical & operational evidence only
not an approval or certification"]:::bound review -. boundary .-> b2["Firm-specific service mapping, impact
tolerance & ownership remain buyer-owned"]:::bound classDef core fill:#e3f1ea,stroke:#5fae87,color:#0B1F3A; classDef svc fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef ext fill:#e7eefb,stroke:#7fa1d8,color:#0B1F3A; classDef bound fill:#fbf4e7,stroke:#d8b877,color:#0B1F3A;
+ decision evidence"]:::core proof["Signed proof-pack manifest
repeatable release gate"]:::svc reg["FCA/PRA evidence-pack register"]:::svc review["Firm review
risk · compliance · audit · accountable owner"]:::svc dd([Buyer diligence decision]):::ext gov --> proof --> reg --> review --> dd reg -. boundary .-> b1["Technical & operational evidence only
not an approval or certification"]:::bound review -. boundary .-> b2["Firm-specific service mapping, impact
tolerance & ownership remain buyer-owned"]:::bound classDef core fill:#e3f1ea,stroke:#5fae87,color:#0B1F3A; classDef svc fill:#eef2f8,stroke:#9fb3d1,color:#0B1F3A; classDef ext fill:#e7eefb,stroke:#7fa1d8,color:#0B1F3A; classDef bound fill:#fbf4e7,stroke:#d8b877,color:#0B1F3A;