Context checksums are best before trusting old evidence.
A checksum packages the details the agent relied on earlier: extracted prices, page titles, screenshots, URLs, approval text, draft output, and timestamps. When the agent resumes, it compares the current continuation context against that package.
- Use it before sending a user-approved text.
- Use it before publishing a reviewed page.
- Use it before using cached browser observations.
State validation is best before acting.
State validation inspects the live system: active account, browser URL, selected cart, form values, permissions, tool availability, and policy boundaries.
The overlap is intentional.
Checksums catch mismatched memory. Validation catches unsafe action conditions. The same resume step can need both signals.
The failure mode is different.
A checksum failure says the remembered context changed. A validation failure says the current action environment is not ready.
Decision rule for builders
When the agent relies on prior evidence, run a checksum. When the agent is about to touch the world, validate live state. When it resumes after minutes or hours, run both.
Checksum asksIs my remembered context still true?
Validation asksIs the current action safe now?