phase

Superseded on 2026-09-21 (adr-2609212115255771): the sequencing layer is dependencies plus the lifecycle shelves, rendered as the Now / Next / Later status block; the phase documents stay as history. See record-families.

A phase is abcd's sequencing layer — an ordered stretch of work that ends in a milestone (a concrete, checkable end condition). Phases replace plugin-version language (v1, v2) as the way the project organises what ships together and in what order. Each phase is a document in .abcd/development/roadmap/phases/ that opens with a product ## Expectation: a working-backwards re-statement, at phase granularity, of what the phase is expected to make true for the user.

A phase sits between the brief (the whole project) and the intent (one user-facing capability) on the question it answers — see adr-9; the layers that replace it are in brief/01-product/03-mental-model.md.

Senses

The word carries two senses in the record, and the glossary fixes one spelling for each (iss-2609012245352480).

The two numberings are not a mapping. Roadmap phases run 0–7 and the brief's plumbing-phases run 0–6; the low numbers coincide, and Phase 7 — Provenance ledger and cold reading has no plumbing-phase of that number at all. A number alone therefore never says which sense is meant, and the qualifier does.

Where the record disagrees. adr-9 writes both "plumbing phases" and "brief plumbing-phases" in one document, and the mental-model chapter's diagram edge is labelled plumbing phase. The glossary fixes the hyphenated plumbing-phase, which is the form roadmap/phases/README.md and every phase doc's ## Scope already use; the unhyphenated instances are the disagreement, not a third sense.

When to use

Use "phase" for an ordered stretch of work that bundles intents and plumbing into a coherent milestone-ending unit. Use it when discussing what order work happens in, or what expectation a stretch of work is measured against. Use "brief plumbing-phase" for a numbered section of the build sequence.

When NOT to use

Do not use "phase" for an individual work block (that is a spec), for a plugin release number (a release version is an output of completing a phase, never the organising unit), or interchangeably with "milestone" — the milestone is the end condition of a phase, not the phase itself. Do not write bare "phase" for a build-sequence milestone, and do not write "build phase" at all: it reads as either sense.

Examples

• "Phase 1 — Substrate ends when the oracle backend ships and project state is reconciled."
• "Phase 1's ## Scope bundles the brief plumbing-phases 0 and 1."
• "Spec spc-5 carries phase: phase-1-substrate in its frontmatter." (The phase: anchor's tooling is specified in spc-66 (predecessor store) — the phase-audit reviewer that reads it and the PA001 verify-exists lint are a design target for the Go binary, not yet shipped; also deferred is the corpus backfill that would make the anchor a standing convention. Phase membership today is still editorial, via each phase doc's ## Scope.)
• "The phase audit reviews delivered reality against the phase's structured ## Phase Acceptance." (Per the adr-9 amendment: the reviewable cut is the structured ## Phase Acceptance bullets, NOT the prose ## Expectation — prose is the narrative re-statement, not the audit target.)

Related terms

• spec — the implementation unit; many specs belong to one phase
• intent — the user-facing capability; a phase bundles a set of intents
• roadmap — the folder the phase docs live in, and the dashboard that renders their progress
• plan — the phase docs are the ordered build plan, a different sense from the intent plan verb
• voyage — the operations namespace recording what abcd did to produce a lifeboat; not a lifecycle arc (that sense is retired per adr-35)