* test(#3866): pin that verify:pre must dispatch every hook kind verify-work.md's verify_pre_hooks step dispatches only `kind == "gate"`, so getWiredKinds reports verify:pre -> {gate} and gen-capability-registry rejects any capability declaring a step or contribution there. The verify lane is therefore closed to capabilities that want to contribute to what UAT covers rather than refuse to let it start. Failing-first: the step, contribution, and exact-kind-set rows are RED; the pre-existing gate row is a green regression pin so the new arms cannot orphan the arm verify:pre already had. Refs #3866 * feat(#3866): dispatch step and contribution hooks at verify:pre verify_pre_hooks dispatched `kind == "gate"` only, so getWiredKinds reported verify:pre -> {gate} and gen-capability-registry's validateHooksWired rejected any capability declaring a step or contribution there. A capability could refuse to let UAT start; it could not contribute to what UAT covers. Add contribution and step arms mirroring execute:wave:post, deferring to references/loop-hook-dispatch.md and carrying its ref.command in-context validation guard ahead of any shell-use prose. A verify:pre step is advisory: it never blocks the start of UAT and an erroring step is routed by its own onError. The gate arm and its check guard are untouched. Give extract_tests an additive consumption seam for the artefacts those steps declare via the existing steps[].produces field -- no new registry field, no new ordering, no invented filename. Manifest-supplied artefact names are validated in-context against an allowlist and resolved only inside PHASE_DIR. With no producing step the derivation is unchanged, pinned by test rather than asserted in prose. Review findings folded in: the artefact-name allowlist (isolated adversarial pass), the artefact-shape contract and the seam-inertness tests (spec axis), and the reference/how-to split so one constraint has one source of truth (standards axis). Closes #3866 * chore(#3866): backfill changeset PR number --------- Co-authored-by: sim <sim@local>
31 KiB
Capability Manifest Reference (capability.json)
Canonical ADRs: ADR-1244 · ADR-894 · ADR-1016 See also: How to develop a capability · Capability Command Reference
Each capability is a folder capabilities/<id>/ (or an overlay root ~/.gsd/capabilities/<id>/ / .gsd/capabilities/<id>/) containing one capability.json declaration.
The file is schema-validated JSON with a common envelope plus a role-typed body (role: "feature", role: "runtime", or role: "reviewer").
Envelope fields
These fields are present for role: "feature", role: "runtime", and role: "reviewer" capabilities.
| Field | Type | Required | Description |
|---|---|---|---|
id |
string (kebab-case) | Yes | Unique identifier; must equal the folder name. The prefix gsd-, gsd-core-, and anthropic- are reserved for first-party use. |
role |
"feature" | "runtime" | "reviewer" |
Yes | Discriminator that selects the body schema. "reviewer" is for lane-only capabilities that ship a reviewer body and nothing else — see Reviewer body below. |
version |
semver string | Yes (1.6.0+) | Semantic version of this capability. The registry rejects a manifest without one. |
title |
string | Yes | Short human-readable label. Must be a non-empty string. |
description |
string | Yes | Longer summary sentence. Must be a non-empty string. |
tier |
"core" | "standard" | "full" |
Yes | Source of truth for install-profile membership and surface cluster assignment. tier propagates via the requires-closure; install profiles are generated from it. |
requires |
string[] | Yes | Capability id values this capability depends on. Must be present as an array (use [] when there are no dependencies). Each entry must exist in the registry, be acyclic, and be tier-monotone (a core capability may not require a standard or full capability; a standard capability may not require a full capability). |
engines |
object | No | Host-compatibility constraint. Sub-field: gsd — semver range string (e.g. ">=1.6.0 <3.0.0"). Acts as a hard gate at install and at load; a mismatch blocks installation and causes the overlay to be skipped with a warning at load time. |
runtimeCompat |
object | Yes (role: "feature") |
Declares which host runtimes this capability can surface through. Validated for every role: "feature" capability (a feature manifest without it fails validation). Sub-fields: supported — a non-empty array of kebab-case runtime ids, or the single wildcard ["*"] for a runtime-agnostic capability; unsupported — an array of kebab-case runtime ids (the wildcard is not permitted here); notes — optional object mapping a runtime id (or "*") to a non-empty explanatory string. The wildcard "*" may not be mixed with concrete ids in the same array, and the reserved names __proto__/constructor/prototype are rejected. |
compatVersions |
object | No | Graceful-downgrade table mapping "<capVersion>" to "<min gsd version>". Only meaningful for sources that enumerate versions (git tags, registry, npm); a bare tarball URL carries one version and simply blocks on incompatibility. |
integrity |
string | No | sha512-<base64> hash of the capability bundle. Verified before extraction when present; mismatch aborts install. |
provenance |
object | No | { sourceRepo: string, commit: string }. Emitted in CI for first-party and curated capabilities. |
author |
object | No | { name: string, email?: string, url?: string }. |
homepage |
string | No | URL. |
repository |
string | No | URL. |
license |
string | No | SPDX licence identifier (e.g. "MIT"). |
keywords |
string[] | No | Arbitrary search tags. |
Feature body (role: "feature")
Feature capabilities declare owned artefacts, lifecycle hooks, a federated configuration slice, and loop extension registrations.
skills and agents
| Sub-field | Type | Description |
|---|---|---|
skills |
string[] | Owned skill stems. Exactly one capability may own each stem across the entire merged registry (first-party ∪ overlay). |
agents |
string[] | Owned agent stems. Same uniqueness constraint as skills. |
The skills stems declared here are disclosed by name as instruction surfaces in the pre-install consent summary (ADR-2363). Bodies are installed verbatim and are not content-scanned — see the capability trust model.
agents are classified as an instruction surface too (ADR-2363 D3), but the stems declared here are not disclosed at the prompt: a third-party capability's agents[] are never staged into the agent's instruction context — the staging path that unions third-party skills into a runtime's skills directory has no equivalent for agents — so naming them would claim a surface that does not exist. This does not make agents safe or inert; it means the mechanism does not yet reach them.
hooks
Non-loop lifecycle hooks.
| Sub-field | Type | Description |
|---|---|---|
event |
string | Hook event name (host-runtime specific). |
script |
string | Path to the hook script, relative to the capability root. The hook command written into the host settings is the realpath-confined absolute path to this script (so it always runs the bundle's own file regardless of the working directory) and is POSIX single-quoted (so an install prefix containing spaces cannot break it). For shell safety the path must contain only [A-Za-z0-9._/-] — no whitespace, no shell metacharacters (; | & $ ` ( ) < > * ? [ ] { } ! ~ # ' " \ newline), no leading -, no absolute path, and no .. segment. A script outside this allowlist fails validation and the capability is rejected. |
config — federated config-key schema slice
The config field is an object whose keys are federated configuration keys contributed by this capability. Each key must be absent from the central config-schema and absent from every other capability's config object (collision fails the build gate). Each entry has the following shape:
| Property | Type | Description |
|---|---|---|
type |
"boolean" | "string" | "number" | "enum" |
Value type. |
default |
(type-consistent) | Default value; must be consistent with type. |
description |
string | Human-readable explanation of the key's effect. |
values |
string[] | enum only. Exhaustive list of permitted string values. |
steps
Steps run at a loop extension point as independent units. Ordering within a point is derived from produces/consumes (topological sort; capability-id is the tiebreak).
| Sub-field | Type | Required | Description |
|---|---|---|---|
point |
string | Yes | One of the 12 valid loop extension point identifiers (see table below). |
ref |
object | Yes | The dispatch target. Exactly one of { "skill": "<stem>" }, { "agent": "<stem>" }, or { "command": "<name>" } (the three are mutually exclusive). A skill/agent stem must be declared in this capability's skills/agents array. |
produces |
string[] | Yes | Artefact names this step produces. Must be present as an array (use [] when it produces none); an omitted produces fails validation. No two capability steps may produce the same artefact at the same point. |
consumes |
string[] | Yes | Artefact names this step consumes. Must be present as an array (use [] when it consumes none); an omitted consumes fails validation. |
onError |
"skip" | "halt" |
Yes | Behaviour on failure; must be present and one of "skip" or "halt" (an omitted onError fails validation). Steps are purely additive — they never halt or redirect the host workflow on their own; a blocking precondition is expressed as a gate. |
when |
string | No | Dotted config key; the step is active only when the key is truthy. Evaluated deterministically at render time; phase-context applicability is the skill's own responsibility. |
fragment |
object | No | Optional inline-or-file prompt fragment attached to the step, with the same { "path": "<relative path>" } or { "inline": "<string>" } semantics as a contribution's fragment. A path is materialised (read and inlined) at load time, resolved against the capability directory and confined to it (.. traversal is rejected). |
contributions
Contributions inject a fragment into a named agent role's prompt at a loop extension point. Multiple contributions into the same agent role render as ordered labelled blocks (<contribution from="<id>">…</contribution>).
| Sub-field | Type | Required | Description |
|---|---|---|---|
point |
string | Yes | One of the 12 valid loop extension point identifiers. |
into |
string | Yes | Agent role name. Must be a role published by that loop extension point in the host contract. |
produces |
string[] | Yes | Artefact names this contribution produces. Use [] when it produces none. |
consumes |
string[] | Yes | Artefact names this contribution reads. Use [] when it reads none. |
fragment |
object | Yes | Either { "path": "<relative path>" } (file content) or { "inline": "<string>" } (literal text). |
when |
string | No | Dotted config key; activates the contribution conditionally. |
onError |
"skip" | "halt" |
No | Behaviour on failure. |
gates
Gates check a condition at a loop extension point and optionally block progression.
| Sub-field | Type | Required | Description |
|---|---|---|---|
point |
string | Yes | One of the 12 valid loop extension point identifiers. |
check |
object | Yes | One of three forms (see table below). Must be present as an object; an omitted check fails validation. |
blocking |
boolean | Yes | Must be present and a boolean; an omitted blocking fails validation. When true, a failed check halts the loop at this point. |
onError |
"skip" | "halt" |
Yes | Behaviour when the check itself errors; must be present and one of "skip" or "halt" (an omitted onError fails validation). |
when |
string | No | Dotted config key; activates the gate conditionally. |
check forms:
| Form | Shape | Blocking permitted | Notes |
|---|---|---|---|
| Query | { "query": "<gsd_run query>" } |
Yes | Deterministic first-party code. |
| Predicate | { "predicate": { "kind": "artifact-exists" | "config-equals" | …, … } } |
Yes | Declarative; no code path. |
| Agent verdict | { "agentVerdict": { "ref": …, "prompt": … } } |
No (forced advisory) | LLM evaluation; non-deterministic checks may not halt the loop. |
Valid point values
The 12 loop extension points are a closed, additive-only vocabulary. Every steps, contributions, and gates entry must use one of these identifiers exactly.
A valid point is necessary but not sufficient: each host workflow decides, per point, which hook kinds its dispatch text handles, and a point may dispatch a subset. The registry build derives the real answer from the host workflows (getWiredKinds() in scripts/gen-loop-host-contract.cjs) and rejects a manifest declaring a kind the point does not dispatch — so an unsupported combination is a build-time error naming the point, the kind, and the kinds that point does cover. It is never a hook that renders and is then silently dropped.
verify:pre dispatches all three kinds. A step there is advisory: it runs before UAT begins and never blocks it — a precondition that must halt verification is a gate. Its produces artefact names are consumed additively by the verify workflow's extract_tests step, which can deepen what UAT covers but cannot suppress a checkpoint. See Develop a capability for the authoring workflow.
| Point | Phase | Position |
|---|---|---|
discuss:pre |
Discuss | Before the discuss step executes |
discuss:post |
Discuss | After the discuss step completes |
plan:pre |
Plan | Before the plan step executes |
plan:post |
Plan | After the plan step completes |
execute:pre |
Execute | Before the execute phase begins |
execute:wave:pre |
Execute | Before each execution wave |
execute:wave:post |
Execute | After each execution wave |
execute:post |
Execute | After the execute phase completes |
verify:pre |
Verify | Before the verify step executes |
verify:post |
Verify | After the verify step completes |
ship:pre |
Ship | Before the ship step executes |
ship:post |
Ship | After the ship step completes |
Runtime body (role: "runtime")
Runtime capabilities describe how GSD projects its artefacts onto one host CLI. The body is a closed 8-axis (plus 4 install-surface) vocabulary; no feature-only fields (skills, agents, steps, contributions, gates, hooks) are permitted. Full semantic specifications, the closed enum values for each axis, and the 16-runtime worked examples are in ADR-1016.
| Axis | Field | Type summary |
|---|---|---|
| Config home | runtime.configHome |
Structured object with kind (dot-home | dot-home-nested | xdg | generic-agents-root), name, optional parent, env[], probe[], probeExists, skillsHome. probeExists is an optional sub-path applied to probe candidates: for generic-agents-root it is a hard filter (a candidate qualifies only if <candidate>/<probeExists> exists); for dot-home-nested it is a preference that makes probing pick the candidate GSD owns (e.g. gsd-core/VERSION) over a bare-existing sibling before falling back — see ADR-1016 and #213/#217. |
| Local config dir | runtime.localConfigDir |
Required dot-prefixed string. The runtime's local content-rewrite directory — the ./ target GSD stamps into rewritten artefact bodies (e.g. ./.claude/ → ./<localConfigDir>/) and the local install dir basename. Backs getDirName() (registry-derived, #1679). Usually .<runtime> (the runtime's home dot-dir), but three runtimes diverge because they read GSD's content from a non-home directory: copilot → .github (GitHub Copilot reads custom instructions from .github/copilot-instructions.md / .github/instructions/; see convertClaudeToCopilotContent rewrites in src/runtime-artifact-conversion.cts), antigravity → .agents (local agent/workflow dir; see the antigravity rewrites in src/runtime-artifact-conversion.cts), kimi → .kimi-code. Distinct from configHome.name (the global install home, which for these three is .copilot / antigravity / agents). Byte-parity-proven against the prior hand-maintained mapping by the golden-install-parity harness. |
| Config format | runtime.configFormat |
Closed enum: settings-json | toml | markdown | markdown-dir | none. |
| Artefact layout | runtime.artifactLayout |
Object with global and local arrays of ArtifactKind (kind, destSubpath, prefix, nesting, recursive, stage). |
| Command style | runtime.commandStyle |
Closed enum: slash-hyphen | shell-var. |
| Hooks surface | runtime.hooksSurface |
Closed enum: settings-json | codex-hooks-json | cursor-hooks-json | copilot-inline | cline-rules | kimi-hooks-toml | none. |
| Sandbox tier | runtime.sandboxTier |
Closed enum: none | codex-agent-sandbox. |
| Support tier | runtime.supportTier |
Integer: 1 (fully tested first-party) | 2 (shipped, lower coverage). |
| Install surface | runtime.installSurface |
Closed enum: settings-json | codex-toml | copilot-instructions | cline-rules | cursor-hooks-json | profile-marker-only. |
| Shared settings | runtime.writesSharedSettings |
boolean. Whether the runtime writes a shared settings.json. |
| Permission writer | runtime.permissionWriter |
null | "opencode" | "kilo" | "antigravity". The finish-time permissions-sidecar writer. |
| Extended hook events | runtime.extendedHookEvents |
string[] over a closed vocabulary: SubagentStop, Stop, PreCompact, FileChanged, BeforeAgent, AfterAgent, BeforeModel, SubagentStart. |
hostBehaviors
runtime.hostBehaviors is a closed vocabulary of per-host behavior switches consumed directly by installer and runtime-adaptation code. A key outside the vocabulary is ignored, with a non-fatal warning naming the capability and the key; it is never a validation error, so a manifest authored against a newer GSD degrades visibly instead of failing the build of a repo that merely reads it.
Adding a key is a reviewed first-party change, which is ADR-1016's intended friction rather than an obstacle: the runtime descriptor expresses every per-host difference as a value over a closed vocabulary, and a host needing a new shape gets a named primitive rather than an open escape hatch.
History.
hostBehaviorswent unvalidated until #2801, and this page previously described it as a deliberate open seam sanctioned by ADR-1016. That attribution was wrong — ADR-1016 does not mentionhostBehaviorsat all. See the ADR-1016 amendment.
The vocabulary holds 59 keys; 39 of them are set by exactly one capability. This table is not exhaustive — it lists the keys with the widest reuse so a reader can pattern-match new ones against the same shape:
| Key | Capabilities declaring it |
|---|---|
reapplyCommand |
9 |
skipSharedHooksInstall |
8 |
frontmatterDialect |
5 |
hyphenNameAgentBody |
3 |
legacyCommandsGsdInstallMigration |
3 |
legacyCommandsGsdUninstall |
3 |
nativePlugin |
3 |
skipUpdateBannerCommand |
3 |
verificationStyle |
3 |
reviewerCli has been removed. It was a boolean that marked a runtime capability as also being a reviewer lane. ADR-2782 replaced it with the reviewer body; it survived one release (1.9.0 → 1.10.0) as a derived legacy alias and was deleted in Phase 7 (#2801). No shipped capability declares it.
If your out-of-tree manifest still sets it: nothing crashes and nothing else about your capability changes — it simply contributes no reviewer lane, and the registry reports a non-fatal warning naming the capability. The warning reaches you at build time on stderr, and at install time through the overlay loader's diagnostics. To restore the lane, declare a reviewer body; Ship a reviewer lane in your capability is the migration path, and the field reference is below.
See ADR-1016 (the runtime descriptor is a closed vocabulary; its 2026-08-09 amendment closes hostBehaviors too) and ADR-2782 (introduces the reviewer body, and D9 retires the reviewerCli alias).
For a minimal role: "runtime" example, see ADR-1016 §Decision 8.
Reviewer body (role: "reviewer", or on any role)
ADR-2782 introduces the reviewer lane: one external CLI or model endpoint that /gsd-review hands a plan to for independent review.
To declare one, follow Ship a reviewer lane in your capability. This section is the field reference behind that guide.
The reviewer body is optional and absent-safe at every layer. A capability with no reviewer body is simply not a lane — that is never a validation error. This is a normative forward/backward-compatibility invariant, not a nicety: a plugin, a runtime, or a future GSD version may omit reviewer entirely with no consequence.
The shape is hybrid:
- A
reviewerbody is admissible onrole: "runtime", so an existing runtime capability —codex,antigravity— keeps one manifest that is both an installable runtime and a reviewer lane. - A third role,
role: "reviewer", exists for lane-only CLIs that GSD never installs into. There are currently 5:coderabbit,gemini,llama-cpp,lm-studio,ollama.
Current role counts across capabilities/: feature 20, runtime 19, reviewer 5.
All 12 shipped lane declarations carry all 13 fields below.
| Field | Type | Notes |
|---|---|---|
slug |
string | Lane identity; grammar ^[a-z0-9][a-z0-9_-]*$. May use _ (lm_studio, llama_cpp) even where the capability folder id is kebab-case (lm-studio). |
flags |
string[] | User-facing CLI flags that select this lane. A lane may declare more than one — antigravity declares --antigravity and --agy. 12 lanes declare 13 flags in total. |
transport |
closed enum | spawn | openai-http. |
probe |
object | Availability check. probe.kind is a closed enum: command-exists | command-capability | http-reachable. command-capability additionally takes binary, needle, and a required timeoutMs — it exists because a bare binary name can be ambiguous (kimi is claimed by both the Kimi Code CLI and the legacy Python kimi-cli), and the timeout bound is mandatory because an unbounded --help | grep probe is this repo's named Unbounded Subprocesses defect. |
invoke |
object | Shape is selected by transport. For spawn: binary, args[], promptChannel (stdin | argv | argv-file-ref | none), outputChannel (stdout | file-arg), outputArg (required when outputChannel is file-arg), modelArg (string or null), effortChannel (none | argv | env), env (optional; an object of environment name/value pairs, string values only, merged over the inherited environment for that one spawn — keys must match the portable environment-name grammar [A-Za-z_][A-Za-z0-9_]*, which is a portability policy rather than an OS limit, and __proto__ is refused because it would be dropped before reaching the child). For openai-http: hostConfigKey, defaultHost, path, modelDiscovery (none | first-from-models-endpoint), fallbackModel, effortChannel. args supports the {{model}}, {{prompt}}, {{effort}}, and {{output}} placeholders. Every field in this object is disclosed at install and bound to the consent signature — env and defaultHost by name in the consent prompt, the rest through a residual, so any change to a declared invoke field forces re-consent. env additionally refuses execution-primitive names — PATH, NODE_OPTIONS, LD_PRELOAD, DYLD_INSERT_LIBRARIES, BASH_ENV, PYTHONPATH, PERL5OPT, RUBYOPT, GIT_SSH_COMMAND, JAVA_TOOL_OPTIONS and siblings, matched case-insensitively (Windows environment lookup is). A lane needing a specific executable declares an absolute binary rather than reshaping the child's PATH. That denylist is defence in depth and not the boundary: it cannot be complete against an arbitrary child, and disclosure runs before validation, so install-time consent — which shows every declared pair and warns on execution-primitive names — is what actually gates them. |
timeoutFloorMs |
number | Measured per-lane floor. Lane divergence here is real and correct — the descriptor's job is to declare divergence in one place, not to promise uniformity. |
emptyOutput |
closed enum | stub-with-stderr | handler-owned. |
reviewsSection |
string | The REVIEWS.md heading this lane renders under. Must be unique across the merged roster. |
evidenceClass |
closed enum | source-grounded | diff-only (diff-only findings are down-weighted in consensus). |
requiresBinaries |
string[] | Extra binaries the lane needs beyond invoke.binary. |
promptBudgetKey |
string or null |
Federated config key bounding prompt size. |
modelConfigKey |
string or null |
Federated config key naming the model, e.g. review.models.kimi-code. |
handler |
closed enum or null |
antigravity | openai-compatible | opencode | null. |
handler is a closed enum of first-party handler names, not an open escape hatch. ADR-1016 explicitly rejected "arbitrary code in the descriptor"; hard shapes are absorbed by adding a named primitive that is reviewed first-party. The consequence, stated plainly: a third-party reviewer lane is strictly data-only. A plugin can ship a lane, but not a quirky lane that needs imperative code — a lane requiring behavior beyond the closed handler set is not expressible and must be proposed and merged first-party.
Uniqueness is enforced across the merged first-party ∪ overlay set: duplicate slug, duplicate flags entry, and duplicate reviewsSection are each build-time violations. Two lanes sharing a reviewsSection heading would silently merge their output in REVIEWS.md, producing apparent consensus that does not exist.
An unknown field inside a reviewer body is a non-fatal warning on stderr, never a build failure (ADR-2782 D4), so a manifest built against a newer GSD degrades visibly rather than crashing.
Example — lane-only role: "reviewer" capability
{
"id": "coderabbit",
"role": "reviewer",
"version": "1.8.0",
"title": "CodeRabbit",
"description": "CodeRabbit CLI — cross-AI /gsd-review reviewer lane only; not a GSD install target (no runtime body, no artifacts).",
"tier": "full",
"requires": [],
"engines": { "gsd": ">=1.8.0" },
"reviewer": {
"slug": "coderabbit",
"flags": ["--coderabbit"],
"transport": "spawn",
"probe": { "kind": "command-exists", "binary": "coderabbit" },
"invoke": {
"binary": "coderabbit",
"args": ["review", "--prompt-only"],
"promptChannel": "none",
"outputChannel": "stdout",
"modelArg": null,
"effortChannel": "none"
},
"timeoutFloorMs": 360000,
"emptyOutput": "stub-with-stderr",
"reviewsSection": "CodeRabbit",
"evidenceClass": "diff-only",
"requiresBinaries": [],
"promptBudgetKey": null,
"modelConfigKey": null,
"handler": null
}
}
Conformance invariants
The following invariants are enforced at build time by scripts/gen-capability-registry.cjs and at install time by the runtime-callable validateCapability() / validateCrossCapability() over the merged first-party ∪ overlay set.
versionis required. The registry rejects any manifest without a semverversionfield.iduniqueness. No two capabilities may share anid. An overlay whoseidcollides with a first-partyidis rejected; first-party always wins.- Skill and agent stem uniqueness. Exactly one capability may own each skill or agent stem across the entire merged registry.
requiresexist and are acyclic. Everyidlisted inrequiresmust exist in the registry; the dependency graph must be acyclic.requiresis tier-monotone. Acorecapability may not require astandardorfullcapability. Astandardcapability may not require afullcapability.pointvalues are from the closed set. Everypointinsteps,contributions, andgatesmust be one of the 12 identifiers above.contribution.intois a published agent role. Theintovalue must be an agent role declared by the host contract for that loop extension point.- Config key exclusivity. A federated config key must be owned by exactly one capability and absent from the central
config-schema. Presence in both is a collision; a half-migrated key fails the build gate. - Artefact production uniqueness per point. No two capability steps may
producesthe same artefact name at the same loop extension point. engines.gsdis a hard gate. A capability whoseengines.gsdrange does not satisfy the installed GSD version is blocked at install and skipped (with a warning) at load time.- Path confinement. Declared module paths may not use parent-directory traversal (
../); modules arerequire()'d only from the capability's own install root. - Reserved namespace. Capability
idvalues beginning withgsd-,gsd-core-, oranthropic-are reserved; third-party capabilities using these prefixes are rejected.
Example — complete role: "feature" capability
The following is the canonical UI design-contract capability from ADR-894. It illustrates all major body sections.
{
"id": "ui",
"role": "feature",
"version": "1.0.0",
"title": "UI design contracts",
"description": "UI-SPEC design contract and retrospective UI audit for frontend phases.",
"tier": "standard",
"requires": [],
"engines": { "gsd": ">=1.6.0" },
"runtimeCompat": { "supported": ["*"], "unsupported": [] },
"skills": ["ui-phase", "ui-review"],
"agents": ["gsd-ui-checker", "gsd-ui-auditor"],
"hooks": [],
"config": {
"workflow.ui_phase": {
"type": "boolean",
"default": true,
"description": "Enable the UI design-contract gate during planning."
},
"workflow.ui_review": {
"type": "boolean",
"default": true,
"description": "Enable the retrospective UI audit."
},
"workflow.ui_safety_gate": {
"type": "boolean",
"default": true,
"description": "Block execution on unmet UI-SPEC contracts."
}
},
"steps": [
{
"point": "plan:pre",
"ref": { "skill": "ui-phase" },
"produces": ["UI-SPEC.md"],
"consumes": ["CONTEXT.md"],
"when": "workflow.ui_phase",
"onError": "skip"
},
{
"point": "verify:post",
"ref": { "skill": "ui-review" },
"produces": ["UI-REVIEW.md"],
"consumes": ["UI-SPEC.md"],
"when": "workflow.ui_review",
"onError": "skip"
}
],
"contributions": [],
"gates": [
{
"point": "execute:wave:post",
"check": { "query": "ui.safety-gate" },
"when": "workflow.ui_safety_gate",
"blocking": true,
"onError": "halt"
}
]
}
Notes on this example:
whenon each hook references its own config key; whether the phase is actually a frontend phase is decided insideui-phase(self-gate).- The
plan:prestep self-skips on non-frontend phases, producing noUI-SPEC.md; theexecute:wave:postgate'sui.safety-gatequery passes gracefully when noUI-SPEC.mdexists. - A
contributionfollows this shape:{ "point": "plan:pre", "into": "planner", "produces": [], "consumes": [], "fragment": { "path": "loop/threat-model.md" }, "when": "workflow.security_enforcement" }(producesandconsumesare required arrays — use[]when empty).