forge-sync

name	forge-sync
description	Use when checking if .forge/ artifacts are stale after a change to requirements, architecture, or any upstream artifact. Use before running /build, /review, or /ship to confirm the artifact chain is consistent. Use when the user says "is anything out of date" or "what needs to be regenerated".

forge-sync

Overview

Scan every .forge/ artifact for <!-- forge:meta --> headers, cross-reference against references/forge-dependency-graph.md, and produce .forge/sync-report.md listing stale artifacts and the topologically-sorted cascade to re-sync. Pairs with every artifact-producing skill — forge-sync does not regenerate anything; it tells you what to re-run.

When to Use

• A change landed in an upstream artifact (PRD edited, architecture updated, contracts revised) and downstream artifacts may be stale
• Before /build, /review, or /ship — confirm the chain is consistent
• After a teammate's PR touches .forge/ — verify your local view is in sync
• User asks "is anything out of date" / "what needs to be regenerated" / "is the chain consistent"

When NOT to Use

• No .forge/ directory exists yet — nothing to sync
• Single greenfield session where no artifacts have been produced
• The user just wants to read an artifact, not check its freshness

Common Rationalizations

Rationalization	Rebuttal
"The change was small, downstream is probably fine"	Small PRD changes cascade into contract mismatches that surface as bugs during build.
"I'll sync later before shipping"	Stale contracts mean /review validates against outdated interfaces. The mismatch is invisible until production.
"Only the architecture changed, tasks are still valid"	Architecture changes invalidate task file-lists and dependency ordering.
"I just want to update one artifact"	Partial syncs leave the chain inconsistent. Run the full cascade.
"I'll trust the timestamps in memory"	Memory lies. Read the headers; they're the source of truth.

Red Flags

• architecture.md references modules not in .forge/contracts/
• tasks.yaml references contracts that don't exist on disk
• PRD describes features not in architecture
• generated_at timestamps show downstream older than upstream
• generated_at strings are not UTC (no Z suffix, or contain +/- offset)
• An artifact's on-disk content sha256 doesn't match its stored content_hash (hand-edited after generation)
• Multiple .forge/ artifacts with no forge:meta headers (untracked → run /forge-migrate)
• User running /build without checking sync first

Core Process

Step 1: Scan headers

For every file under .forge/, extract the <!-- forge:meta --> block (or # forge:meta for YAML). Capture: generated_by, generated_at, depends_on, content_hash. Artifacts without a header are recorded as "untracked".

For each header, validate before trusting:

• generated_at MUST be ISO 8601 UTC with Z suffix. If it contains an offset (+05:30, -08:00) or no zone marker, flag as INVALID_TIMESTAMP and recommend re-running the source skill.
• content_hash must be 8 hex chars. Anything else → INVALID_HASH (re-run source skill).

Step 1b: Recompute content_hash and compare

For every tracked artifact, recompute sha256 over the file body with the forge:meta block stripped, take the first 8 hex chars, and compare against the stored content_hash.

• Match → trust the header.
• Mismatch → mark MODIFIED (hand-edited after generation). Downstream is potentially stale even if generated_at is newer than upstream's. Recommend the user either re-run the source skill (to bless the edit) or revert the manual change.

MODIFIED is a higher-severity signal than STALE: stale means "upstream moved on," modified means "we lost the chain of provenance entirely."

Step 2: Load the canonical graph

Read references/forge-dependency-graph.md. This is the source of truth for which artifact depends on which. Skill-claimed depends_on is validated against this graph; if a skill claims a dependency the graph doesn't list, flag it.

Step 3: Topological order

Build the dependency DAG. Walk it depth-first to produce a topological order: idea-brief → prd → (architecture, competitive, testing-strategy) → (contracts, api-design, …, gtm, tasks) → (tasks-summary, parallel-plan).

Step 4: Check each artifact (hash-snapshot comparison)

For each artifact A with non-empty depends_on:

• If a dependency D doesn't exist on disk — mark A as MISSING_DEP (the chain is broken).
• For each D listed in A.depends_on:
  • Resolve globs (.forge/contracts/*.md → each concrete file).
  • Look up A.generated_from[D] — the snapshot of D's content_hash at the moment A was generated.
  • Compare against D's CURRENT content_hash (from its forge:meta).
  • Mismatch → mark A as STALE (upstream drifted from snapshot; downstream must regenerate).
  • No generated_from entry for D (legacy artifact predating this schema) → fall back to timestamp comparison (D.generated_at > A.generated_at → STALE) and emit a soft warning to upgrade via /forge-migrate.
  • D is MODIFIED (Step 1b detected hash mismatch on D itself) → A is STALE regardless of generated_from (the chain of provenance is broken upstream).
• If D has no forge:meta header at all — mark A as UNKNOWN (can't verify; recommend /forge-migrate then re-run).
• Otherwise — UP_TO_DATE.

Hash snapshots make this O(1) per dependency. No tree walks, no cascade edits, no timestamp ambiguity. The downstream file is never modified to record upstream changes — the snapshot is frozen at generation time, and the staleness check happens at sync time.

Step 4b: Detect orphaned contract references

tasks.yaml and parallel-plan.md reference contracts by name. If the architecture step was re-run and a contract was renamed (payment-service.md → billing-service.md), the reference in tasks.yaml will dangle even though both files have current timestamps.

For each artifact that lists contract references:

• Extract every .forge/contracts/<name>.md reference (from contracts: fields in tasks.yaml, from prose in tasks-summary.md and parallel-plan.md).
• Check each exists on disk.
• Any missing reference → mark the referencing artifact as BROKEN_REF with the dangling filename quoted.

BROKEN_REF is higher severity than STALE — stale means re-running fixes it; broken-ref means the dependency graph itself is inconsistent and someone must reconcile the naming.

Step 4c: Read .forge/feedback/ for reverse-cascade entries

For every file under .forge/feedback/:

• Read its forge:meta and body.
• If status: PENDING:
  • Extract target_artifact (from the depends_on field in the header — single-element list).
  • Mark the target artifact as FEEDBACK_PENDING (or NEEDS_REVIEW if the body's Severity: line says so).
  • Carry the entry's path into the report so the user can read the finding.
• If status: RESOLVED or status: DEFERRED: skip; informational only.

A target artifact in FEEDBACK_PENDING or NEEDS_REVIEW state cascades STALE to its downstream — the upstream is known-incomplete, so anything downstream that depends on it is suspect.

Step 4d: Cross-artifact conflict detection

For each pair where the cross-precedence table in the dependency graph says one artifact must conform to another:

• api-design.md operation/endpoint definitions vs each contracts/<module>.md Provides section
• database-design.md schema fields vs contracts/ Input Types/Output Types

When operations/types defined in both diverge in shape (name match, but different signature/fields), mark the subordinate artifact as CONFLICT with the divergence quoted. The contract artifact wins; the subordinate must update.

Step 4e: ADR review-due and tasks-diverged

For each ADR under .forge/adr/:

• If last_reviewed_at is more than 90 days old AND status is Accepted → REVIEW_DUE (soft signal, does not cascade).

For .forge/tasks.yaml:

• Count tasks with status: split or status: blocked since the last /plan run (compare against generated_at of the file).
• If ≥3 → TASKS_DIVERGED (recommend re-running /plan).

Step 4f: Sync-report self-staleness (#27)

After determining all the above, also check .forge/sync-report.md (the previous run's output, if it exists):

• If any tracked artifact has generated_at newer than sync-report.md's generated_at → previous sync report is SELF_STALE. Mention this in the new report's preamble so the user knows the prior report was misleading.

Step 4g: Soft dependencies

For each artifact whose forge:meta contains a soft_depends_on field:

• Apply the same generated_at comparison against each entry as Step 4 does for depends_on.
• If any soft upstream is newer → SOFT_STALE (separate section in the report; does NOT cascade to downstream as STALE).

Soft-stale is advisory. The user reviews; the downstream is not blocked.

Step 5: Build the cascade

Stale artifacts cascade downstream. If architecture.md is stale, every artifact depending on it is implicitly stale even if its own headers haven't tripped. Walk the graph: a stale node taints all descendants. The cascade list is the topologically-sorted set of skills to re-run, deduplicated.

Step 6: Write .forge/sync-report.md

# .forge/ Sync Report
Generated: <ISO 8601 UTC timestamp with Z suffix>
Previous report status: SELF_STALE (3 artifacts changed since last sync at 2026-05-12T08:00:00Z)

## Broken references (chain inconsistent — fix first)
| Artifact | Dangling reference | Action |
|---|---|---|
| .forge/tasks.yaml | .forge/contracts/payment-service.md | Reconcile rename or re-run /architect + /plan |

## Modified artifacts (hand-edited after generation)
| Artifact | Stored hash | Disk hash | Action |
|---|---|---|---|
| .forge/prd.md | a3f1b2c4 | 9d8e7f6a | Re-run /spec to bless edits OR revert manual change |

## Feedback pending (reverse cascade)
| Target artifact | Severity | Source | Entry |
|---|---|---|---|
| .forge/contracts/payment-service.md | FEEDBACK_PENDING | build (T-042) | .forge/feedback/2026-05-14T103000Z-build.md |
| .forge/architecture.md | NEEDS_REVIEW | secure | .forge/feedback/2026-05-13T160000Z-secure.md |

## Conflicts (subordinate artifact diverges from authoritative)
| Subordinate | Authoritative | Divergence | Action |
|---|---|---|---|
| .forge/api-design.md `POST /payments/refund` | .forge/contracts/payment-service.md `refund()` | api-design lists no idempotency key; contract requires it | Update api-design |

## Stale artifacts (action required)
| Artifact | Depends on | Last generated | Dependency updated | Action |
|---|---|---|---|---|
| .forge/architecture.md | .forge/prd.md | 2026-05-10T09:00:00Z | 2026-05-13T14:22:00Z | Run /architect |
| .forge/contracts/*.md | .forge/architecture.md | 2026-05-10T09:00:00Z | (stale parent) | Run /architect |
| .forge/tasks.yaml | .forge/prd.md + architecture.md + contracts/* | 2026-05-10T09:00:00Z | (stale parent) | Run /plan |

## Soft-stale (advisory — review before shipping)
| Artifact | Soft upstream changed | Action |
|---|---|---|
| .forge/accessibility.md | .forge/design-system.md updated 2026-05-13T14:00:00Z | Re-read tokens; refresh contrast checks if relevant |

## Tasks diverged
| Artifact | Detail | Action |
|---|---|---|
| .forge/tasks.yaml | 4 tasks split, 1 blocked since last /plan run | Run /plan to re-baseline |

## ADRs due for review (>90 days)
| ADR | Last reviewed | Status |
|---|---|---|
| .forge/adr/003-event-bus.md | 2026-02-10 | Accepted — re-affirm or supersede |

## Cascade order
Run these skills in order to fully sync (excluding NEEDS_REVIEW items, which require human decision first):
1. Address feedback entries (re-run /architect to incorporate FEEDBACK_PENDING items targeting contracts/)
2. /architect — updates architecture.md + contracts/ + adr/
3. /plan — updates tasks.yaml + tasks-summary.md

## Up to date
| Artifact | Last generated |
|---|---|
| .forge/idea-brief.md | 2026-05-08T11:30:00Z |
| .forge/testing-strategy.md | 2026-05-12T16:45:00Z |

## No header (untracked)
| Artifact | Note |
|---|---|
| .forge/design-system.md | Generated before headers were added. Run /forge-migrate then re-run /design to refresh. |

## Schema violations
| Artifact | Issue |
|---|---|
| .forge/observability.md | generated_at is `2026-05-12T10:00:00+05:30` — must be UTC with Z suffix. Re-run /observe. |

Also prepend a forge:meta header to .forge/sync-report.md itself (generated_by: forge-sync, generated_at: <ISO 8601 UTC with Z>, depends_on: [<every .forge/ file scanned>] — paths only, never hashes, generated_from: {<each scanned path>: <its content_hash at scan time>}, content_hash: <sha256 first 8 of THIS file's body>).

Step 6b: Write .forge/index.md (summary for context-hungry consumers)

Large projects accumulate 20-30 .forge/ artifacts. A skill that needs to "read everything" (cross-validation, redaction, demo-narrative) blows its context window on full file loads when most of what it needs is just the summary. Emit a compact index alongside the sync report so consumers can scan first and selectively load.

Write .forge/index.md with one row per tracked artifact:

<!-- forge:meta — same shape as sync-report.md's header -->

# .forge/ Index
Generated: <ISO 8601 UTC>
Artifacts: <count>  |  Total size: <KB>

| Artifact | Generated by | Last updated | Status | Size | One-line summary |
|---|---|---|---|---|---|
| .forge/prd.md | spec-driven-development | 2026-05-13T14:22Z | UP_TO_DATE | 12 KB | Forge Skills v3.5 product requirements |
| .forge/architecture.md | architecture-and-contracts | 2026-05-13T15:00Z | STALE | 8 KB | System design with 6 modules, REST + SSE |
| .forge/contracts/auth-service.md | architecture-and-contracts | 2026-05-13T15:00Z | UP_TO_DATE | 2 KB | AuthService contract — JWT issuance + validation |
| .forge/feedback/2026-05-14T103000Z-build.md | feedback | 2026-05-14T10:30Z | PENDING | 1 KB | PaymentService contract missing refund() |

Rules:

• Status uses the same vocabulary as the sync report (UP_TO_DATE / STALE / MODIFIED / UNKNOWN / MISSING_DEP / BROKEN_REF / FEEDBACK_PENDING / NEEDS_REVIEW / SOFT_STALE / CONFLICT / REVIEW_DUE / TASKS_DIVERGED).
• One-line summary is extracted from the first # Title heading or > blockquote of each artifact, truncated to 60 chars. For YAML, use the first non-comment field's value.
• Sort by canonical pipeline order (idea-brief → prd → architecture → contracts → ... → feedback entries last).
• Size is human-readable (KB / MB).

Index is for machine consumption primarily — skills like cross-validation and demo-narrative should read .forge/index.md first, then load only the artifacts they actually need. Humans can read it too, but the sync report is the human-readable surface.

Prepend a forge:meta header to .forge/index.md identical in shape to the sync-report's header (same depends_on set, same generated_from snapshot).

Step 7: Report to user

If everything is up to date: "All .forge/ artifacts are in sync. No action needed."

If stale: print the cascade order and ask: "Run these in order? Y/n" — but DO NOT run them. forge-sync is read-only by design; it diagnoses, never regenerates. The user runs the cascade commands themselves.

Verification

• Every stale artifact is identified with a specific cascade action
• Cascade order is topologically sorted (no downstream runs before its upstream)
• Report includes stale, up-to-date, no-header, modified, broken-ref, feedback-pending, conflict, soft-stale, tasks-diverged, ADR review-due, AND schema-violation sections
• No false positives — artifact marked stale only when D.generated_at > A.generated_at OR a dep is MODIFIED/FEEDBACK_PENDING/NEEDS_REVIEW
• content_hash recomputed and compared for every tracked artifact (catches manual edits)
• generated_at validated as UTC with Z suffix (catches timezone drift)
• Contract references in tasks.yaml and parallel-plan.md checked against disk (catches orphans)
• .forge/feedback/*.md PENDING entries surfaced; targets flipped to FEEDBACK_PENDING or NEEDS_REVIEW
• api-design.md ↔ contracts/*.md operation shapes cross-checked for CONFLICT
• Soft dependencies (soft_depends_on field) checked; SOFT_STALE reported separately from STALE
• ADRs older than 90 days with status Accepted flagged as REVIEW_DUE
• tasks.yaml split/blocked counts inspected → TASKS_DIVERGED if ≥3
• Previous .forge/sync-report.md checked against newest .forge/ mtime; SELF_STALE noted in preamble if applicable
• forge-sync does NOT regenerate anything; it only reports
• .forge/sync-report.md written with its own forge:meta header (UTC, Z suffix, valid hash)
• .forge/index.md written with one row per tracked artifact (path, generated_by, last_updated, status, size, one-line summary), sorted by canonical pipeline order, with its own forge:meta header