Architecture

CB is a three-component system:

Gateway

• Accepts requests.
• Selects a route deterministically.
• Executes the selected backend.
• Settles the output under a policy envelope.
• Writes evidence records (WALs) that can be verified later.

Signer

• Optional isolated signing boundary.
• Receives a digest/envelope and returns a signature.
• Produces seal.jsonl records.

Operator Terminal

• Non-secret viewport.
• Ledger-first evidence surface.
• Human-in-the-loop governance actions are explicit and justified.