the-custodian/canon/architecture/adr-007-workplan-identity-and-repo-worker-topology.md

id	type	title	status	decided_by	date	accepted	tags
ADR-007	architecture-decision-record	Workplan Identity Uniqueness, Single Registrar, and Repo Worker Topology	accepted	Bernd Worsch	2026-08-16	2026-08-17	architecture workplans identity state-hub repo-manager agents registrar

ADR-007: Workplan Identity Uniqueness, Single Registrar, and Repo Worker Topology

Status

Accepted 2026-08-17. Identifier uniqueness, the registrar model, lifecycle protection, and worker topology are settled.

Remediation of existing collisions (§ Migration) remains an open ruling. It is disruptive, touches six repositories, and no active work depends on it — all five duplicated identifiers are finished.

Context

On 2026-08-16, STATE-WP-0080 was found registered twice, in two different databases, with two different workplan UUIDs and two disjoint sets of task UUIDs:

Registrar	Workplan UUID	Reachable at 127.0.0.1:8000
Workstation hub (make api, local postgres)	03f38314	yes
railiance01 primary, via custodian-sync@railiance.local	bbfce36a	404

Both write their IDs into the same git-tracked workplan file, so each sync overwrites the other's IDs and the file flip-flops on every round trip. The same commit (ff909e1, "renormalize lifecycle state [auto]") also promoted the workplan proposed → active without human review.

A fleet scan of 955 hub workplans (525 with parseable PREFIX-WP-NNNN identifiers) found this is not an isolated incident. Two distinct identity defects are live:

Prefix reuse across repositories:

CUST-WP-      → state-hub, the-custodian
RAIL-BS-WP-   → railiance-bootstrap, railiance-cluster
RAILIANCE-WP- → railiance-apps, railiance-forge, railiance-platform, railiance-telemetry

PRJ-WP- is a latent fourth: statehub register derives it from the prj- flavor marker, so every project repository would collide (see RMGR-WP-0004).

Running-number reuse:

CUST-WP-0000       the-custodian ×2
CUST-WP-0010       the-custodian ×2
CUST-WP-0045       the-custodian ×2
RAILIANCE-WP-0015  railiance-platform, railiance-apps
RAILIANCE-WP-0016  railiance-platform ×2, railiance-apps

RAILIANCE-WP-0015 is actively cited in operational memory as the cnpg-backup gate in railiance-apps; a second record of the same name in railiance-platform makes that citation ambiguous.

The C-26 consistency check already flags prefix nonconformance within a repo against a canonical prefix, but nothing enforces uniqueness across repos, and nothing prevents number reuse.

Decision

1. A workplan identifier is globally unique. PREFIX-WP-NNNN names exactly one workplan across the entire fleet, for all time.

• A workplan prefix is owned by exactly one repository. No two repositories may use the same prefix.
• A running number is never reused within a prefix, including after a workplan is cancelled, archived, or deleted. Numbers are allocated forward only.
• Prefixes are derived from the project or repository identity, never from a flavor marker or category (PRJ-WP- is invalid by construction).

2. Hub identifiers stored in repository files must be derivable, not database-local. The defect is structural: a database-local key is stored in a shared artifact, so each database overwrites the other's value on every sync. It also inverts ADR-001 — a file carrying a hub's private key is the file holding hub state.

Target state (C2). state_hub_workstream_id and state_hub_task_id become deterministic: UUIDv5 derived from the globally unique PREFIX-WP-NNNN identifier. Every instance computes the same value independently, writeback becomes idempotent, and any number of hub instances may coexist without coordination. The field shape is unchanged, so consumers keep working; only the provenance of the value changes.

This has a hard prerequisite: deterministic derivation from a non-unique identifier would manufacture collisions rather than remove them. Two project repos sharing PRJ-WP- would compute the same UUID for different workplans. Decision 1 must therefore be enforced before derivation ships.

Interim state (A). Until derivation lands, exactly one instance writes hub identifiers into repository files. Other instances may read, project, and serve, but must not mint workplan or task UUIDs into git-tracked files. The interim registrar is the automated production instance; workstation hubs are development read replicas.

The interim is policy, enforced by discipline, and it has a real cost: registration requires connectivity to the registrar, so disconnected work cannot register. That cost is accepted only until C2 removes the need for it, at which point the number of hub instances becomes an availability choice rather than a correctness constraint.

Rejected. Collapsing to a single shared database (workstation hubs pointing at the production database) would also make identifiers consistent by construction, but it eliminates offline capability — cutting directly against STATE-WP-0068 (offline write buffer and edge relay) — and couples all local work to tunnel availability.

Ownership. Both the interim guard and the derivation belong to repo-manager under decision 747011c6, which already places file-backed record indexing and reconciliation there. Building either in state-hub would invest in a component being retired under STATE-WP-0079.

Migration scope for C2: 758 workplan files across the fleet currently carry these fields.

3. Lifecycle status is not automatically promoted. An automated normalization pass may report drift; it may not move a workplan from proposed to active. proposed means awaiting human review, and an automation that promotes it destroys the meaning of the review gate.

4. Repository manipulation is performed by a worker agent in that repository. This is the default topology.

• A worker acting in repo X owns changes to repo X.
• Multiple independent top-level workers inside a single repository are an exception, requiring an explicit reason, not a routine mode of operation.
• Concurrent independent writers are what turned a two-registrar bug into repeated git divergence.

5. Project (prj-) repositories may act across their participating repositories. When work is governed by a project repo, its tasks may direct changes across every repository the project names, through the project's work agent, where that is more efficient than delegating.

This is a deliberate, scoped exception to decision 4: the project repo already owns cross-repo sequencing and its SCOPE.md names its participants, so its authority is declared rather than ad hoc. It does not license a worker in an arbitrary repository to reach into others.

Consequences

Positive. Workplan identifiers become citable without qualification. Hub IDs stop flip-flopping in git. The proposed status regains meaning. Cross-repo authority becomes something a repository declares rather than something any session assumes.

Negative. Existing collisions must be remediated (see below), which is disruptive. Workstation sessions lose the ability to register workplans directly and must route through the registrar or a worker in the owning repo. Prefix allocation needs a fleet-level registry, which is new machinery.

Enforcement. Prefix ownership, uniqueness, and forward-only numbering are repository standards, so they belong to Repo Manager under decision 747011c6 (RMGR-WP-0004), not to a hub. Canon defines the rule; Repo Manager checks it.

Migration — needs a separate ruling

Three prefixes and five identifiers are already colliding. Remediation options, in increasing cost:

1. Freeze and forward-fix. Accept existing collisions as historical, enforce uniqueness only for new workplans. Cheapest; leaves RAILIANCE-WP-0015 permanently ambiguous.
2. Renumber the live collisions only. Fix identifiers that are still cited or active; leave finished/archived duplicates alone.
3. Full renaming. Give railiance-apps, railiance-forge, railiance-platform, railiance-telemetry distinct prefixes, likewise railiance-bootstrap/railiance-cluster and state-hub's legacy CUST-WP- files. Touches six repositories and every inbound reference.

Recommendation: option 2, with option 3's prefix split applied only to repos that are still creating new workplans under a shared prefix — a shared prefix that is still growing keeps generating new collisions, while a dormant one does not.

All five duplicated identifiers are currently finished, so no active work is blocked by deferring this.

References

• Decision 747011c6 — repository standards belong to Repo Manager
• ADR-001 — workplans originate as repo files; hub is a read model
• RMGR-WP-0004 — repository standards conformance and governed scaffolding
• STATE-WP-0080 — register scaffolding handoff
• Fleet scan 2026-08-16: 955 hub workplans, 525 parseable identifiers, 3 reused prefixes, 5 reused identifiers