# ACP Snapshot Replay This graph explains what a snapshot scenario proves: recorded real-model session logs are replayed keylessly, ACP stdout is normalized and diffed, and scenario workspaces preserve tool side effects that the UI stream alone cannot prove. ```mermaid sequenceDiagram participant Recorder as Real API recording participant Fixture as snapshot fixture participant Workspace participant Replay as llm-replay adapter participant ACP as acp-agent subprocess participant Expected as stdout expected output Recorder->>Fixture: session.jsonl + workspace inputs Fixture->>Workspace: seed files and hook configs Fixture->>Replay: recorded StreamChunk script Replay->>ACP: deterministic llm/stream chunks ACP->>Workspace: bash, fs, and hook side effects ACP->>Expected: normalized sessionUpdate stream Expected-->>ACP: diff must be empty ``` The fs and hook snapshot matrix is valuable because it proves world state, hook decisions, and failed tool-card rendering, not just that replay returns text. Maintenance mode: curated Mermaid sequence based on the snapshot test harness.