# Checkpoint

> A durable record of progress, decisions, files, or state that lets an agent resume safely.

- Category: Context & Memory
- Stage: Rising
- Also called: Save point, Resume point
- Canonical: https://www.joelcsaji.com/ai-dictionary/checkpoint

## Plain English

A bookmark for work, not just a chat transcript.

## Example

An agent writes a progress file after each feature with tests run, files changed, and remaining tasks.

## Why it matters

Checkpoints reduce duplicated work and make long-running automation inspectable.

## Related

- [Compaction](https://www.joelcsaji.com/ai-dictionary/compaction)
- [Trace](https://www.joelcsaji.com/ai-dictionary/trace)
- [Long-Running Agent](https://www.joelcsaji.com/ai-dictionary/long-running-agent)

## Mentioned in

- [Fable 5, Export Controls, and GLM 5.2](https://www.joelcsaji.com/blog/fable-5-export-controls-and-glm-5-2)

## Sources

- [Anthropic: Effective Harnesses](https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents)