Antigravity Integration (Agent Skills spec)

Antigravity implements the Agent Skills (agentskills.io) spec — a skill folder with a SKILL.md file, name/description loaded up front, full instructions loaded on activation. The spec itself does not mandate any particular discovery directory (it defines the skill-folder format, not a root path), and Antigravity's own native chat panel reads skills straight from .agent/skills/ — confirmed by a live test: placing this plugin's three skills at .agent/skills/<skill-name>/SKILL.md and typing /jira-task-executor in Antigravity's native (Gemini-based) chat ran it immediately, no settings changed. Three working paths:

• Method 1 (recommended) — the bundled Claude Code extension. Antigravity ships the official anthropic.claude-code VS Code extension pre-installed. This is Claude Code itself running inside Antigravity — no adaptation layer, and disable-model-invocation: true works exactly as it does in plain Claude Code.
• Method 2 — Antigravity's native .agent/skills discovery. Works out of the box in Antigravity's own chat panel; no experimental setting to enable. disable-model-invocation: true is a Claude Code-specific frontmatter field that isn't part of the agentskills.io spec, so it does nothing here — its spec-side analogue is a per-skill agents/openai.yml carrying policy: allow_implicit_invocation: false, and this plugin's skills need it (install step 2 below).
• ⚠️ Method 3 (unconfirmed) — Antigravity's chat.useClaudeSkills scanner. A second, separate native mechanism found by inspecting the installed product's code (not by a live test): an off-by-default setting that reads .claude/skills/ instead of .agent/skills/. Real and independent of Method 2, but untested live — see its own section below.

Verification note. The .agent/skills discovery path and its slash invocation (/<skill-name>, no setting toggle) are live-verified (specifically tested on Antigravity IDE 1.23.2 and agy 1.0.8; other releases are untested) — confirmed by directly testing this plugin's skills in Antigravity's native chat panel. This directly overrides an earlier version of this doc, which claimed (from static analysis of the installed Antigravity 1.107.0 build) that no .agent/skills reader existed — that search was exhaustive over literal string matches but evidently missed a dynamically-constructed path, since a live test is stronger evidence than a grep that can only prove absence of a literal substring, not absence of the feature. Static analysis of the same build did independently find a second, separate mechanism — an off-by-default chat.useClaudeSkills setting that reads .claude/skills/ — which is real (confirmed in code) but wasn't needed for the live test to succeed, so it's documented as Method 3, a fallback rather than the primary path. What has not been live-tested under Method 2 is ambient (non-slash) invocation — only explicit slash invocation was tested — so the agents/openai.yml policy file that suppresses it is documented below as a required install step rather than as a verified behavior.

Prerequisites

• Jira auth configured — per-request Basic auth from .jst/jira-sdlc-tools.local.env, no login step (see jira-api-reference.md §9)
• gh (GitHub CLI) authenticated
• .jst/jira-sdlc-tools.env and .jst/jira-sdlc-tools.local.env in your project root — see project-config.md
• Method 1 only — nothing extra: the Claude Code extension ships inside Antigravity already.
• Method 2 only — no setting to enable and no extension to install, but you do write one agents/openai.yml per skill (install step 2).
• ⚠️ Method 3 only (unconfirmed) — Antigravity Settings access to toggle an experimental setting, plus the same per-skill agents/openai.yml (see below).

Install / Wire-up Steps

Method 1: Use the bundled Claude Code extension (recommended)

Antigravity is a VS Code–family IDE and ships anthropic.claude-code as a built-in extension, so this is the same flow as CURSOR.md Method 1:

1. Open the Claude Code panel/terminal inside Antigravity (unverified which exact UI surface — sidebar icon vs. integrated terminal running claude — this method was confirmed by inspecting the installed extension, not by clicking through the GUI; Method 2 below is the one that was live-tested end to end).
2. Register the marketplace:

   /plugin marketplace add <GITHUB_OWNER>/<GITHUB_REPO>

   or, for a local clone:

   /plugin marketplace add </ABSOLUTE/PATH/TO/MARKETPLACE/ROOT>

3. Install the plugin: /plugin, Discover tab, select jira-sdlc (or /plugin install jira-sdlc@<MARKETPLACE_NAME>).
4. Reload the window. Skills are available as /jira-sdlc:<skill-name>, identical to plain Claude Code.

Method 2: Antigravity's native .agent/skills discovery (live-verified)

1. Copy the skill folders into an .agent/skills/ tree at your project root:

   mkdir -p .agent/skills
   cp -a </ABSOLUTE/PATH/TO/MARKETPLACE/ROOT>/plugins/jira-sdlc/skills/* .agent/skills/

2. Add an agents/openai.yml policy file to each skill — this is the agentskills.io-side analogue of Claude Code's disable-model-invocation: true, which Antigravity does not read:

   for skill in jira-task-assigner jira-task-executor jira-task-reviewer; do
     mkdir -p ".agent/skills/$skill/agents"
     printf 'policy:\n  allow_implicit_invocation: false\n' \
       > ".agent/skills/$skill/agents/openai.yml"
   done

   Same content as CODEX.md step 2 — the file is not part of the Claude plugin source, it's the adaptation you write per platform. All three skills are built to be run deliberately (they create Jira issues, push branches, open PRs), so leaving it out means the model may load one from ambient chat context on a prompt that merely sounds like the job.
3. No chmod step needed: every script call in these skills is written as bash "<path>", never a bare ./script.sh, so the executable bit is never required.
4. .agent/skills/ is a manual copy, not committed — gitignore it (a single * inside a .agent/.gitignore works). There is no sync script; when the plugin updates, re-run step 1's copy.
5. Nothing to reload or toggle — Antigravity's native chat reads the directory directly.

⚠️ Method 3 (unconfirmed): chat.useClaudeSkills + .claude/skills

⚠️ Unconfirmed. Every step below comes from reading the installed product's code, not from running it. No one has enabled the setting and invoked a skill this way end to end. Use Method 1 or 2 unless you are deliberately exploring this path.

Found by inspecting the installed Antigravity 1.107.0 build's config schema and skill-loading code — a second, independent native discovery mechanism, separate from Method 2 and not required for it. Untested live; included here in case Method 2 ever regresses or you'd rather use a path that also covers other spec-compliant clients (Claude Code itself reads project skills from this same .claude/skills/ path).

1. Enable the experimental setting — search "Claude Skills" in Antigravity Settings (chat.useClaudeSkills), or set it directly:

   // settings.json
   "chat.useClaudeSkills": true

   Default is false. The setting is flagged restricted in the product's config schema, meaning an untrusted workspace's own .vscode/settings.json cannot silently turn it on for you — enable it yourself in your user settings, then trust the workspace.
2. Copy the skill folders into a .claude/skills/ tree — the code scans this path both at the workspace root and in your user home directory (~/.claude/skills/); a user-home copy applies across every project, a workspace copy applies to this one only:

   mkdir -p .claude/skills
   cp -a </ABSOLUTE/PATH/TO/MARKETPLACE/ROOT>/plugins/jira-sdlc/skills/* .claude/skills/

   If you already did CURSOR.md Method 2 (drop-in symlinks under ~/.claude/skills/), this scan picks that up too — no separate copy needed.
3. Add the same per-skill agents/openai.yml as Method 2 step 2, under .claude/skills/$skill/agents/ — this scanner reads only name/description out of the frontmatter, so disable-model-invocation: true is inert on this path too.
4. Same no-chmod-needed note as Method 2 applies.
5. .claude/skills/ (the workspace copy) is a manual copy, not committed — gitignore it. No sync script here either.
6. Reload the window.
7. Invocation syntax is unverified — the code path that parses .claude/skills/ frontmatter only extracts name/description, the same fields Method 2 exposes, so /skill-name slash invocation plausibly works the same way it does for Method 2, but this has not actually been tried. Confirm before relying on it.

Invoking the Three Skills

Method 1 — identical to Claude Code: type /jira-sdlc:jira-task-assigner, /jira-sdlc:jira-task-executor, or /jira-sdlc:jira-task-reviewer in chat.

Method 2 — type the bare skill name as a slash command in Antigravity's native chat: /jira-task-assigner, /jira-task-executor, or /jira-task-reviewer (no jira-sdlc: namespace — live-verified for /jira-task-executor, the other two follow the same .agent/skills/<name>/ layout and are expected to match but were not individually retested).

⚠️ Method 3 (unconfirmed) — presumed identical bare-name slash invocation to Method 2 (/jira-task-executor, etc.), since the code exposes the same name field the same way, but this is unverified — not tried live.

Platform-Specific Caveats

disable-model-invocation: true

• Method 1: honored as-is — same runtime as Claude Code, nothing to add.
• Methods 2 and 3: the frontmatter field itself does nothing. It is a Claude Code plugin-specific extension, not part of the agentskills.io spec's frontmatter (the published spec's table lists only name, description, license, compatibility, metadata, allowed-tools), so you re-express the intent in agents/openai.yml instead:

  policy:
    allow_implicit_invocation: false

  Write it for all three skills (install step 2) — this plugin's skills are explicit-only by design and this file is what carries that across. Note what it does and doesn't buy you: explicit invocation (/jira-task-executor) works with or without the file — that much is live-verified — so the policy is not a prerequisite for running a skill. It's what stops the router from semantic-matching an ambient prompt onto a skill that creates Jira issues and opens PRs. Antigravity's enforcement of the flag has not been live-tested (see below), so on Methods 2/3 treat the suppression as intended-but-unconfirmed; Method 1 is the path where explicit-only is guaranteed.

⚠️ Method 3 is an unconfirmed fallback, not a requirement

Method 2's live test succeeded via .agent/skills/ without touching chat.useClaudeSkills at all, so Method 3 is not a dependency of Method 2 — it's a separate, code-confirmed mechanism worth knowing about mainly if .agent/skills/ ever stops working across an Antigravity update.

Drift — the Method 2 copy is not synced

Same caveat as Codex: .agent/skills/ is a manual copy of plugins/jira-sdlc/skills/. When the plugin updates, the copy goes stale silently — there is no sync script or version pin. Re-run the copy recipe (Install step 1) after every plugin update.

agents/openai.yml — write it, but don't over-trust it

A search of the installed Antigravity 1.107.0 build found no code reading openai.yml or an allow_implicit_invocation field, and the live test invoked a skill fine without one. Neither observation means the policy is ignored: a grep over a shipped build can only prove a literal string is absent, not a feature — the same reasoning that made this doc wrongly declare .agent/skills/ unsupported until a live test contradicted it (see the Verification note). Nor does explicit invocation working tell you anything about implicit invocation, which is the only thing the policy governs.

So the file is part of the install for Methods 2 and 3, and it costs nothing if Antigravity turns out to ignore it. What's still open is whether ambient invocation is actually blocked — nobody has tried to provoke it. Until someone does, Method 1 remains the recommended path for this plugin.