---
type: trekbrief
brief_version: "2.0"
created: 2026-05-13
task: "Backward-compat fixture for v5.0-style brief"
slug: legacy-brief-example
project_dir: .claude/projects/2026-05-13-legacy-brief-example/
research_topics: 0
research_status: complete
auto_research: false
interview_turns: 3
source: interview
---

# Task: Legacy brief example

## Intent

A pre-v5.1 brief that pre-dates the phase_signals field. Used by
tests/validators to confirm backward-compatibility: the brief is accepted
without phase_signals as long as brief_version is < 2.1.

## Goal

Validator returns valid: true. The sequencing gate
(BRIEF_V51_MISSING_SIGNALS) does NOT fire for brief_version 2.0.

## Success Criteria

- Validator passes.
- No BRIEF_V51_MISSING_SIGNALS error in r.errors.