State, Memory, and Checkpoints
State, Memory, and Checkpoints
Key jargon
| Term | Plain-language meaning |
|---|---|
| State | The authoritative data describing the current workflow position and values. |
| Memory | Information retained for later use, often selected or summarized from prior interactions. |
| Checkpoint | A durable snapshot from which execution can resume. |
| Event log | An append-only sequence of facts describing state transitions. |
Key concepts
- Conversation history, workflow state, and long-term memory solve different problems and should not be conflated.
- Durable checkpoints make interruption, approval, retry, and incident reconstruction possible.
Concept map
flowchart LR
A["Observe event"] --> B["Persist state transition"]
B --> C["Create checkpoint"]
C --> D["Resume with selected memory"]| Kind | Example | Lifetime |
|---|---|---|
| Turn context | Current user message | One invocation |
| Run state | Completed steps and pending approval | One workflow run |
| Artifact | Draft, report, code patch, dataset | Project-defined |
| User memory | Preference explicitly saved for future use | Until expiry/deletion |
| Knowledge memory | Curated facts with source and version | Until superseded |
| Model weights | Learned behavior from training | Model release |
Do not call the conversation window “memory” without qualification. Durable memory needs consent, provenance, namespace, conflict handling, retention, and deletion.
Checkpoint contents
Task contract, policy version, current state, completed effects, pending effects, artifacts, evidence references, budgets, and safe resume instruction.
Exercise
Design a resumable three-step research workflow. Simulate interruption after step two and show how the checkpoint prevents repeating an external action.