# Runtime Receipt

> Live proof that a tool or surface works right now, not that it worked at last deploy.

Category: observability

A runtime receipt is fresh evidence that a tool or surface actually responds correctly at this moment.

## Why it matters
Code that passed CI is not the same as a surface that works in production. Agents act against live systems, and live systems drift, expire, and break under you. A runtime receipt is the difference between "should work" and "just confirmed it does," which is the only version an agent should trust before acting.

## In practice
Before trusting a surface, you pull a fresh receipt: call it, capture the response, confirm the shape. The receipt is dated and tied to the exact surface, so staleness becomes visible instead of assumed away.

## Where it shows up in my work
In foundation3 I require a runtime receipt after edits to the live tool surface. The same discipline applies to any agent acting on systems it does not own.

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Source: https://ryanhunter.io/lexicon/runtime-receipt
Part of the Agent Infrastructure Lexicon by Ryan Hunter. https://ryanhunter.io/lexicon