/substrate:graph-spec

Turn a finished spec into a bead DAG: one epic + child beads wired by blocked-by: edges, all tagged with the canonical epic label epic:<slug>. The DAG is the input to substrate's parallel-execution doctrine — beads in the same topological wave touch no shared blocker and can be dispatched to worktree-isolated subagents at once.

This skill produces the graph; it does not run it. Execution is the parallel-execution orchestrator's job (docs/doctrine/agents-parallel-execution-doctrine.md), or a plain phase-by-phase /substrate:execute pass.

Arguments

<spec-path> — path to a spec at docs/tasks/ongoing/<slug>/<slug>-spec.md. If omitted, discover it (see Step 1).

When to run

• A spec exists and its Prompt Execution Strategy section is filled (phases → steps → verify → gate).
• You want the work decomposed into independently-dispatchable beads before execution — especially when phases contain file-disjoint steps that could run in parallel.
• Invoked automatically as the last step of /substrate:architect-spec, or by hand on any existing spec.

When to REFUSE

Fail fast — abort with a one-line explanation, never fall back to a guess.

Protocol you operate under

• Execution grammar: docs/protocol/sdd/execution-format.md (phases → steps → verify → gate) — the structure you decompose.
• DAG algorithm: mirrors /substrate:synthesize-session Step 8 (pairwise blocked-by inference + Kahn cycle detection). Same "bead DAG" dialect on purpose — one graph vocabulary across the plugin.
• Consumer: docs/doctrine/agents-parallel-execution-doctrine.md (single-writer tracker, integration branch, file-disjoint waves).

Workflow

Step 1 — Resolve the spec

If a path was passed, use it. Else glob docs/tasks/ongoing/**/*-spec.md:

• exactly one match → use it;
• several → list them and ask which;
• none → REFUSE per the table.

Derive <slug> from the containing directory name (docs/tasks/ongoing/<slug>/...). That slug is the whole coordination key: the epic label is epic:<slug>, deterministically, so /substrate:synthesize-session later files follow-up beads under the same label without any handshake.

Read the spec. Confirm it has a Prompt Execution Strategy section; if not, REFUSE.

Step 2 — Resolve the bead-tracker

Same resolution as /substrate:synthesize-session (keep them identical):

1. If .substrate/config.json sets "bead-tracker", honor it (tbd | none | other).
2. Else auto-detect tbd: .tbd/config.yml exists AND a tbd binary is callable — command -v tbd succeeds, OR npx --no-install get-tbd --version succeeds. Else none.

• tbd → beads are canonical; this skill creates them via tbd create. Substitute npx --no-install get-tbd for tbd throughout if no global binary is on PATH.
• none → markdown is canonical; beads live at docs/tasks/ongoing/<slug>/beads/<bead-slug>.md. blocked-by: in frontmatter is the only edge record (no tbd dep).

Step 3 — Decompose the spec into bead candidates

Walk the Prompt Execution Strategy. Each step (#### Step N.M) is one bead candidate; collapse trivially-coupled sibling steps only when they edit the same file and share a single Verify block. For each candidate capture, in memory (no writes yet):

• title — imperative, scoped (e.g. "Add requireStoreOwner guard to convex/stores.ts").
• phase / layer — the owning phase and its layer-hint (domain / backend / frontend / infra / cross-cutting).
• creates — files, symbols, exports, tables the step introduces or modifies (read the step body + its Verify block).
• consumes — files/symbols/commands the step depends on existing.
• invalidated tests (reconcile) — existing tests that assert behavior this bead changes (distinct from any new tests the step adds). A behavior change to an existing symbol / contract / exported member / required-dependency almost always breaks a test that pinned the old behavior, yet the step body rarely names that test. Reverse-scan the test tree for tests referencing the changed symbol/file/contract and fold each matching test file into this bead's creates (its write-scope) with a one-line reconcile: note ("asserts prior behavior of X"). Skipping this is the single most common cause of a mid-run stall: the test lives outside the bead's declared Files, so the group-runner can't touch it and the break surfaces only at the integrated re-gate. Purely-additive beads (new files, no change to an existing symbol) have no invalidated tests — leave this empty.
• gate — the step's Verify commands, inlined (a subagent runs these; per the parallel-execution doctrine it never touches tbd or git). Compare it to substrate.yaml's gate.{compile,test,lint}: if the bead's gate is a strict subset of gate.*, or omits a suite the bead's layer is actually covered by (e.g. a frontend bead that runs only tsc, not the vitest suite), tag the bead gate-scope: partial in its body. That tells the orchestrator its per-bead green is a fast pre-check only, and that the wave's union re-gate — not this narrow gate — authorizes the merge (agents-parallel-execution-doctrine.md §Supporting → Re-run the gate on the integrated branch). A gate that equals or supersets gate.* needs no tag.
• acceptance criterion — binary pass/fail lifted from the step + its gate.

Step 4 — Build the DAG

Mirror /substrate:synthesize-session Step 8:

1. Pairwise scan. For each ordered pair (A, B), mark B blocked-by A iff B's consumes references a file/symbol/export/table in A's creates. This is richer than the linear phase order: two steps in the same phase that touch disjoint files land with no edge between them → same wave → parallel. Record a one-line reason per edge.
2. Layer backstop. If two beads share a file in their creates set, serialize them with an edge (later phase blocked-by earlier) even absent a symbol dependency — the parallel-execution doctrine forbids two beads editing one file in a wave.
3. Cycle detection (Kahn). Compute in-degrees; peel zero-in-degree nodes. If any remain → a cycle exists. REFUSE: print the cycle (A → B → C → A) and ask the user to split or drop a bead. Never emit a cyclic DAG.
4. Encode blocked-by: on each bead.

Step 4.5 — Partition into context-budget windows

The DAG is now cycle-free; cut it into agent-sized windows so no group-runner's context rots or auto-compacts. Read execution.context-budget from substrate.yaml (default 0.4 if absent — a deviatable prior, not a hard gate). Then:

1. Estimate per-bead cost. Walk beads in topological order. For each, estimate cost = Σ(bytes of its Files/creates+consumes) + heavy-ref surcharge (schema / contract / migration reads the bead must load) + gate-log weight + effort(XS…L). This is a heuristic prior, not a measurement — round generously.
2. Accumulate into windows. Open window-1; add beads in topological order, summing cost. When the running total would cross context-budget (as a fraction of one agent's usable window), close the current window and open the next. Snap boundaries to file-adjacency: never split a chain of co-edited beads (overlapping Files) across two windows — co-edited beads share a warm worktree, so they belong to the same window; file-disjoint chains fall into separate windows (isolation, parallel where edges allow). Adjacency wins over the raw cost cut when they conflict.
3. Flag under-decomposition. If a single bead's cost alone exceeds context-budget, do not silently over-fill a window: warn and recommend splitting that bead (it is too heavy for one runner), then place it in its own window so the run can still proceed.

The partition is a deviatable prior: the orchestrator MAY re-batch at dispatch time (logging the deviation). See agents-parallel-execution-doctrine.md §Grouping & windows.

Step 4.55 — Bind doctrine to write-scope (doctrine:<id> labels)

Windows exist and every bead has a write-scope. Bind each bead to the doctrines that govern the files it will edit, at graph time, so a dispatcher can push the right doctrine into the worker's prompt instead of hoping the worker goes looking. Only the manifest's paths key answers the file question — triggers matches a brief (prose) at spec time, paths matches a write-scope (files) at graph time (docs/doctrine/agents-doctrine.md §3.1).

1. Read the manifest at docs/doctrine/doctrine-manifest.yaml. Take each entry's id and its optional paths:, parsed in inline-list form only — paths: [docs/doctrine/**, x/y.sh], one line — exactly how doctrine-lint.sh parses pointers. A block sequence (paths: then - a/**) is not the declared form and the tooling cannot read it: report it as a manifest bug, do not accommodate it.
2. Silent no-op when there is nothing to bind. No manifest, or no entry declares paths: → stamp nothing and say nothing. Not a warning, not an abort: substrate must keep graphing specs in repos that never adopted the key, and a warning would fire on every run in every one of them.
3. Intersect. A bead's write-scope is creates ∪ modifies — Step 3's creates set, which has already absorbed the invalidated-test files. consumes is read-only and does not bind. A bead is bound to <id> iff any path in its write-scope matches any glob in that entry's paths:. Match relative to the repo root and permissively — a * may cross / (the same reading doctrine-lint.sh uses for its rot guard), so docs/doctrine/** matches docs/doctrine/agents-doctrine.md, and a bead whose declared scope is itself a directory glob (convex/**) matches a doctrine glob rooted there.
4. Stamp doctrine:<id> — one label per matching entry; a bead may carry zero, one, or several. <id> is the manifest's id field verbatim (not the filename, not the path). It is the key downstream consumers resolve with bash docs/scripts/doctrine-digest.sh <id>; any other spelling breaks that chain silently.
5. Exempt the terminal node. The doctrine-reconciliation bead Step 4.6 shapes (the spec's Phase N: Doctrine Reconciliation step, or the node you synthesize when the spec lacks one) gets no generic doctrine:<id> labels — even though its docs/doctrine/** write-scope would match every doctrine that governs doctrine files. Its whole brief is reconciliation against the fully integrated epic; stamping it would bind it to a near-arbitrary subset and drown the signal. Step 4.6's contract is the only one it carries.

Worked example, against this repo's manifest (agents → paths: [docs/doctrine/**, docs/scripts/doctrine-lint.sh]; agents-parallel-execution → paths: [docs/scripts/bead-graph.sh]):

Step 4.6 — Force the terminal doctrine-reconciliation node

Every spec ends with Phase N: Doctrine Reconciliation (per spec-template.md). Its bead is not an ordinary node — it is the epic's mandatory terminal node that applies the ratify-only doctrine change the feature earned, in-epic. It never queues a doctrine-amendment and there is no downstream sink. Shape it explicitly, overriding the generic decomposition:

1. Tag it kind: doctrine-reconciliation (an additive tag alongside epic:<slug>), so the orchestrator can identify the terminal node.
2. Edge it blocked-by every other bead in the epic. It must see the fully integrated feature — no other bead may land after it. This is deliberately the one node that collapses parallelism at the end; that's correct.
3. Write-scope = docs/doctrine/**. Put docs/doctrine/** in its creates/Files. Editing doctrine files is ordinary working-tree change a group-runner may make in its worktree — it is not a tracker write, so the single-writer invariant is untouched.
4. Solo terminal window. Give it its own group:<window-N> as the last window (it is blocked-by everything, so it is structurally its own final wave regardless). Never fold it into a feature window.
5. Ratify-only gate. Its gate is the epic's full union gate re-run on the integrated tip — green proves the mutation only codified what the code already did. Do not tag it gate-scope: partial.

If the spec somehow lacks a Doctrine Reconciliation phase, synthesize this node anyway — it is mandatory per the contract; warn that the spec was missing it.

Step 5 — Persist the epic + beads

Preview the full bead list in DAG order inline, then ask: Create 1 epic + N beads under epic:<slug> now? (Y / n / select) — default Y (binary gate, no default-escape suffix). select enters a per-bead y / n / skip loop.

Branch A — tbd (single-writer; you are the only writer):

1. Epic bead: tbd create "Epic: <spec title>" --type epic -l "epic:<slug>" --file <spec-ref> (a tempfile holding the spec path + one-line summary; mktemp, unlink after). Capture its id as <epic-id>.
2. Child beads, in DAG order so blocked-by: resolves to already-assigned ids:
   • render the bead body (acceptance criterion + inlined gate + state-transfer prompt) to a tempfile,
   • tbd create "<title>" --type task --parent <epic-id> -l "epic:<slug>" -l "group:<window-N>" [-l "doctrine:<id>" …] --file <tmp>, where <window-N> is the bead's window from Step 4.5 and the zero-or-more doctrine:<id> flags are its Step-4.55 bindings, one -l each (add -l "kind:doctrine-reconciliation" for the terminal node from Step 4.6 — which carries no doctrine: labels); capture the id, unlink the tempfile (unconditional cleanup, even on failure),
   • stamp the spec back-link so a cold runner can re-open context: include spec: <spec-path>#<owning-phase-or-step> in the bead body (and, when the tracker supports it, tbd update <bead-id> --spec <spec-path>),
   • for each blocker: tbd dep add <bead-id> <blocker-id>.
3. --label epic:<slug> is the canonical grouping — the label, not the parent link, is the join key /substrate:synthesize-session and bead-graph.sh rely on. --parent is the nicety on top. group:<window-N> is the partition membership the orchestrator reads (and MAY re-batch) per agents-parallel-execution-doctrine.md §Grouping & windows. doctrine:<id> is the graph-time binding dispatchers push on: the orchestrator inlines the window's digests via doctrine-digest.sh <id>, and a daemon lane reads the label-named doctrines first.
4. Do not tbd sync here — batch sync stays the orchestrator's call at epic close (parallel-execution doctrine, Policy 3).

Branch B — none: write each bead to docs/tasks/ongoing/<slug>/beads/<bead-slug>.md with blocked-by:, epic: <slug>, group: <window-N> (its Step-4.5 window), doctrine: [<id>, …] (its Step-4.55 bindings — omit the key entirely when there are none), and spec: <spec-path>#<owning-phase-or-step> in frontmatter. The markdown file is the bead.

Step 6 — Show the shape

Render the DAG so the user (and any future agent) can see parallel vs. sequential structure:

bash docs/scripts/bead-graph.sh --epic <slug>                 # topological waves (default)
bash docs/scripts/bead-graph.sh --epic <slug> --format mermaid  # paste-able graph TD

Print the waves view inline. Under tbd, the script reads the beads you just created; under none, tell the user the waves view requires tbd and print the DAG from your in-memory layering instead.

Step 7 — Hand off

Print verbatim:

✔ Spec graphed into a bead DAG.

Epic label: epic:<slug>   ·   1 epic + N beads   ·   W waves (see above)

Inspect any time:
  bash docs/scripts/bead-graph.sh --epic <slug>
  bash docs/scripts/bead-graph.sh --epic <slug> --format mermaid

To execute in parallel, hand this DAG to the orchestrator per
docs/doctrine/agents-parallel-execution-doctrine.md (single-writer tracker,
integration branch, file-disjoint waves). For a simple sequential pass:

  claude /substrate:execute docs/tasks/ongoing/<slug>/<slug>-spec.md

Constraints

• MUST derive <slug> from the spec directory and tag every bead (epic + children) with epic:<slug>. The label is the canonical epic identity — it is the contract with /substrate:synthesize-session and bead-graph.sh. Do not skip it.
• MUST emit exactly one terminal doctrine-reconciliation node per epic (Step 4.6): tagged kind: doctrine-reconciliation, blocked-by every other bead, docs/doctrine/** in its write-scope, in its own solo terminal group:<window-N>. This is the in-epic sink for doctrine change — the graph MUST NOT rely on a downstream doctrine-amendment queue.
• MUST cycle-check via Kahn before persisting and REFUSE on a cycle. A cyclic "DAG" is a bug, not a plan.
• MUST be the single writer to tbd (parallel-execution doctrine Policy 1). Never hand the tbd CLI or git push to a subagent.
• MUST NOT tbd sync — batch sync is the orchestrator's, at epic close.
• MUST NOT execute the beads, write feature code, or open worktrees. This skill only produces the graph.
• MUST NOT double-create: if an epic for <slug> already exists, render the existing DAG and offer to add only missing beads.
• MUST clean up every tempfile it renders (unlink even on partial failure).
• MUST run the invalidated-tests reverse-scan for every behavior-changing bead and fold the affected existing test files into that bead's Files/write-scope with a reconcile: note. A behavior change whose broken test sits outside the bead's Files is a guaranteed mid-run stall — the group-runner can't touch what isn't in scope.
• MUST stamp doctrine:<id> (Step 4.55) on every bead whose write-scope intersects a manifest entry's paths: globs, using the manifest's id verbatim so doctrine-digest.sh <id> resolves it downstream — and MUST leave the terminal kind: doctrine-reconciliation node unstamped. When no manifest exists or no entry declares paths:, the step is a silent no-op — never a warning, never an abort.
• MUST tag a bead gate-scope: partial when its inlined gate is a strict subset of substrate.yaml's gate.* (or omits a suite its layer is covered by), so the orchestrator treats the per-bead green as a pre-check and relies on the wave's union re-gate to authorize the merge.
• SHOULD keep bead granularity at one-step-one-bead unless steps are file-coupled and share a Verify block — over-splitting inflates the DAG, under-splitting kills parallelism.