# Phase 118: Scratchpad Contract - Context

**Gathered:** 2026-04-11
**Status:** Implemented and verified
**Mode:** First implementation phase for `v1.62`

<domain>
## Phase Boundary

Open `v1.62` by locking a bounded contract for topic-scoped scratch and
negative-result runtime memory.

</domain>

<decisions>
## Implementation Decisions

### Locked decisions

- represent scratch and negative results as runtime-side durable state, not as
  canonical scientific truth
- keep route comparison and negative-result memory under one bounded scratchpad
  surface
- require helper, service, CLI, and schema coverage before production wiring

</decisions>

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*Phase: 118-scratchpad-contract*
*Context captured on 2026-04-11 after Phase 118 implementation and verification*
