feature: add subagent support for gemini and antigravity

.claude-plugin/marketplace.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://anthropic.com/claude-code/marketplace.schema.json",
   "name": "context-engineering-kit",
-  "version": "3.8.0",
+  "version": "3.8.1",
   "description": "Hand-crafted collection of advanced context engineering techniques and patterns with minimal token footprint focused on improving agent result quality.",
   "owner": {
     "name": "NeoLabHQ",
@@ -55,7 +55,7 @@
     {
       "name": "sadd",
       "description": "Introduces skills for subagent-driven development, dispatches fresh subagent for each task with code review between tasks, enabling fast iteration with quality gates.",
-      "version": "3.3.0",
+      "version": "3.3.1",
       "author": {
         "name": "Vlad Goncharov",
         "email": "vlad.goncharov@neolab.finance"
@@ -77,7 +77,7 @@
     {
       "name": "sdd",
       "description": "Specification Driven Development workflow commands and agents, based on Github Spec Kit and OpenSpec. Uses specialized agents for effective context management and quality review.",
-      "version": "3.4.0",
+      "version": "3.4.1",
       "author": {
         "name": "Vlad Goncharov",
         "email": "vlad.goncharov@neolab.finance"

.github/workflows/sync-provider-formats.yml

@@ -0,0 +1,100 @@
+# Keeps the root-level Gemini CLI / Antigravity CLI provider bundle
+# (skills/, agents/, gemini-extension.json, plugin.json) in sync with
+# plugins/*/skills, plugins/*/agents, and the marketplace manifest.
+#
+# `just sync-provider-formats` (see justfile) fully regenerates those four
+# paths from the current plugin content. This workflow runs it on every PR
+# that could change the bundle and reacts to exactly four outcomes:
+#   1. Sync ran fine, no drift               -> pass, nothing to do.
+#   2. Sync ran fine, drift found, same-repo  -> commit + push the fix back.
+#   3. Sync ran fine, drift found, fork PR    -> fail with instructions
+#      (the default GITHUB_TOKEN cannot push to a fork's branch).
+#   4. Sync itself errored (e.g. a skill/agent name collision) -> fail and
+#      surface the script's own error message, without touching git state.
+name: Sync provider formats
+
+on:
+  pull_request:
+    paths:
+      - "plugins/**/skills/**"
+      - "plugins/**/agents/**"
+      - ".claude-plugin/marketplace.json"
+
+# Only the push-back path (outcome 2) needs write access; everything else
+# only reads the checked-out tree.
+permissions:
+  contents: write
+
+# A fresh push to the same PR should supersede an in-flight run rather than
+# race it for the push-back step.
+concurrency:
+  group: sync-provider-formats-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  sync:
+    name: Sync provider formats
+    runs-on: ubuntu-latest
+    steps:
+      # `ref: head.sha` (rather than the branch name) works for both
+      # same-repo and fork PRs: GitHub exposes the PR head commit on the
+      # base repo's refs even when the branch itself only exists in a fork.
+      - name: Checkout PR head commit
+        uses: actions/checkout@v7
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Install just
+        uses: extractions/setup-just@v4
+
+      # Captures the recipe's own exit code as a step output instead of
+      # letting it fail the step directly, so "script errored" and "script
+      # succeeded but produced a diff" stay two distinct, separately
+      # branchable signals (handled by the two steps below).
+      - name: Run sync-provider-formats
+        id: sync
+        run: |
+          if just sync-provider-formats > sync-provider-formats.log 2>&1; then
+            echo "outcome=ok" >> "$GITHUB_OUTPUT"
+          else
+            echo "outcome=error" >> "$GITHUB_OUTPUT"
+          fi
+          cat sync-provider-formats.log
+
+      # `git add -A` (not `git diff` alone) is required here: the recipe
+      # deletes and recreates these paths from scratch, so a newly added
+      # plugin skill/agent is untracked, not merely modified, and plain
+      # `git diff` would miss it entirely.
+      - name: Check for drift against the committed bundle
+        id: diff
+        run: |
+          git add -A -- skills agents gemini-extension.json plugin.json
+          if git diff --cached --quiet; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            git diff --cached --stat
+          fi
+
+      - name: Fail with instructions (fork PR is out of sync)
+        if: steps.diff.outputs.changed == 'true' && github.event.pull_request.head.repo.fork == true
+        run: |
+          echo "::error::The provider bundle (skills/, agents/, gemini-extension.json, plugin.json) is out of date. Run 'just sync-provider-formats' locally and commit the result, then push again. Automatic push-back is unavailable for pull requests from forks because the default GITHUB_TOKEN cannot push to fork branches."
+          exit 1
+
+      # Files are already staged by the diff-check step above, so this only
+      # needs to commit and push - no separate `git add`.
+      #
+      # HEAD_REF is passed through an env var rather than interpolated
+      # directly into the script, since branch names come from the PR
+      # payload and are attacker-controlled input (security hardening
+      # guidance for GitHub Actions inline scripts).
+      - name: Commit and push regenerated bundle
+        if: steps.diff.outputs.changed == 'true' && github.event.pull_request.head.repo.fork == false
+        env:
+          HEAD_REF: ${{ github.head_ref }}
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git commit -m "chore: sync provider formats (gemini/antigravity bundle)"
+          git push origin "HEAD:$HEAD_REF"

.gitignore

@@ -149,3 +149,6 @@ vite.config.ts.timestamp-*
 
 #Ignore cursor AI rules
 .cursor/rules/codacy.mdc
+.specs/scratchpad/*.md
+.specs/analysis/*.md
+.specs/reports/*.md

.specs/tasks/done/add-gemini-antigravity-cli-support.feature.md

@@ -0,0 +1,122 @@
+---
+title: Add support for Gemini and Antigravity CLI
+---
+
+## Initial User Prompt
+
+add support for gemini and antigravity cli
+
+### Context
+
+Currently used in README.md approach with isntallation through `vercel-labs/skills` not works well with majority of providers due to lack of support for agents installation from vercel-labs/skills cli.
+
+But gemini have own standard for extensions, that uses gemini-extension.json and antigravity cli uses plugin.json
+
+#### Gemini CLI: use an extension
+
+Gemini CLI extensions can bundle both Agent Skills and subagents:
+
+```
+my-gemini-extension/
+├── gemini-extension.json
+├── skills/
+│   └── code-review/
+│       ├── SKILL.md
+│       └── scripts/
+└── agents/
+    ├── reviewer.md
+    └── researcher.md
+```
+Minimal manifest:
+
+```json
+{
+  "name": "my-plugin",
+  "version": "1.0.0",
+  "description": "My skills and specialized agents"
+}
+```
+Install it with:
+
+```bash
+gemini extensions install https://github.com/your-org/my-gemini-extension
+```
+
+#### Antigravity CLI: use a native plugin
+
+Antigravity CLI has a plugin system specifically designed to package skills, agents, rules, MCP servers, and hooks:
+
+```
+my-antigravity-plugin/
+├── plugin.json
+├── skills/
+│   └── code-review/
+│       └── SKILL.md
+├── agents/
+│   ├── reviewer.md
+│   └── researcher.md
+├── mcp_config.json
+├── hooks.json
+└── rules/
+```
+Manifest:
+
+```json
+{
+  "$schema": "https://antigravity.google/schemas/v1/plugin.json",
+  "name": "my-plugin",
+  "description": "My skills and specialized subagents"
+}
+```
+
+### Requirements
+
+Key constraint driving this design: neither Gemini CLI nor Antigravity CLI has a marketplace/registry concept (unlike Claude Code's `marketplace.json`) — each install command installs exactly one extension/plugin, and a remote/URL-based `gemini extensions install` clones the whole repo and requires the manifest at the **repo root**, with no subdirectory support. So per-plugin selective install (like `/plugin install reflexion@...`) isn't achievable for Gemini/Antigravity; instead, all plugins' `skills/`/`agents/` content is merged into one root-level bundle installable as a single extension/plugin.
+
+#### 1. Repo structure & build output (generated, committed by CI)
+
+- At the repo root: `gemini-extension.json` (`name`/`version`/`description` sourced from `.claude-plugin/marketplace.json`'s top-level fields) and `plugin.json` (Antigravity schema, same source fields; only used by the antigravity-only fallback install, not the primary flow).
+- At the repo root: `skills/` and `agents/` — union of every `plugins/<name>/skills/*` and `plugins/<name>/agents/*` folder, copied as-is with original names preserved (no prefixing, no nesting).
+- Collision policy: if two plugins define a same-named skill/agent folder, the sync must hard-fail with an error naming both source plugins. Names are currently unique across all plugins.
+- Per-plugin outcome: every plugin merges whatever `skills/`/`agents/` it has (including `reflexion`'s `skills/`). `reflexion`'s `hooks/` folder is left out of the merge — not a skip of the plugin, hooks were never a sync target. `ddd` and `tech-stack` are `rules/`-only today so they contribute nothing to the merge (not a special-case exclusion — if they ever add `skills/`/`agents/`, it merges automatically). Other plugins' non-skills/agents folders (`scripts/`, `tasks/`, `prompts/` in `mcp`/`sadd`/`sdd`/`fpf`) stay untouched in place.
+
+#### 2. justfile: `sync-provider-formats`
+
+- Plain bash in the justfile (matching `sync-docs-to-plugins`/`sync-plugins-to-docs` style), using `jq` for manifest generation — no external script files.
+- Full regeneration every run: delete and rebuild `skills/`, `agents/`, `gemini-extension.json`, `plugin.json` from scratch (no incremental patching), so removed plugin content disappears from the bundle automatically.
+- Idempotent: re-running with no plugin changes produces an identical output (no git diff).
+
+#### 3. GitHub Action (CI)
+
+- Triggers on `pull_request`, scoped with a path filter to `plugins/**/skills/**`, `plugins/**/agents/**`, and `.claude-plugin/marketplace.json` (avoids running on unrelated PRs, e.g. docs-only changes).
+- Runs `just sync-provider-formats`, then diffs the result against what's committed.
+- If different and the PR branch is same-repo (not a fork): commit and push the regenerated files back onto the PR branch.
+- If different and the PR is from a fork: fail the check with an instructive message (run `just sync-provider-formats` locally and commit) — GitHub Actions' default token can't push to fork branches.
+- If the sync script itself errors (name collision): fail the check without committing anything, surfacing the conflict directly.
+
+#### 4. README installation instructions
+
+Convert `### Step 1: Install Marketplace and Plugins` to four sibling `<details><summary>` spoilers (not subheadings):
+
+1. **Claude Code** — unchanged (`/plugin marketplace add`, `/plugin install <name>@...`).
+2. **Gemini CLI or Antigravity CLI** (new) — primary flow:
+   ```bash
+   gemini extensions install https://github.com/NeoLabHQ/context-engineering-kit
+   agy plugin import gemini
+   ```
+   Antigravity-only fallback (no Gemini CLI installed):
+   ```bash
+   git clone https://github.com/NeoLabHQ/context-engineering-kit
+   cd context-engineering-kit
+   agy plugin install .
+   ```
+   Note inline: installs every plugin's skills/agents as one bundle — no per-plugin selection like Claude Code's `/plugin install`; content from `rules/`-only plugins (`ddd`, `tech-stack`) and `reflexion`'s `hooks/` isn't included.
+3. **Cursor, Codex, OpenCode and others** — existing `npx skills add` flow (Antigravity removed from this heading, since it now has its own native spoiler above). Add caveat: each provider uses its own agent format, so this path won't give subagent-using plugins the full experience — only skills transfer cleanly.
+4. **Alternative installation methods** (OpenSkills) — existing content, promoted from a nested spoiler to a top-level sibling spoiler.
+
+
+
+
+## Description
+
+// Will be filled in future stages by business analyst

README.md

@@ -43,9 +43,10 @@ Updates from key releases:
 
 ### Step 1: Install Marketplace and Plugins
 
-#### Claude Code
+<details>
+<summary>Claude Code</summary>
 
-Open Claude Code and add the Context Engineering Kit marketplace
+Open Claude Code and add the Context Engineering Kit marketplace:
 
 ```bash
 /plugin marketplace add NeoLabHQ/context-engineering-kit
@@ -61,14 +62,52 @@ Install any plugin — for example, reflexion:
 
 Each installed plugin loads only its specific agents, commands, and skills into Claude's context.
 
-#### Cursor, Antigravity, Codex, OpenCode and others
+</details>
+
+<details>
+<summary>Gemini CLI or Antigravity CLI</summary>
+
+**Gemini CLI installation**
+
+```bash
+gemini extensions install https://github.com/NeoLabHQ/context-engineering-kit
+```
+
+**Antigravity CLI installation:**
+
+**Important**: This command requires Gemini CLI to be installed. 
+
+```bash
+gemini extensions install https://github.com/NeoLabHQ/context-engineering-kit
+agy plugin import gemini
+```
+
+**Antigravity CLI installation without Gemini CLI:**
+
+```bash
+git clone https://github.com/NeoLabHQ/context-engineering-kit
+cd context-engineering-kit
+agy plugin install .
+```
+
+**Note:** This installs every plugin's skills and agents as a single bundle — there's no per-plugin selection like Claude Code's. Unfortunately, Gemini and Antigravity CLI does not support per-plugin selection. But you can delete skills and agents that you don't need, after installation.
+
+</details>
+
+<details>
+<summary>Cursor, Codex, OpenCode and others</summary>
 
 Run the [vercel-labs/skills](https://github.com/vercel-labs/skills) command in your terminal:
 
 ```bash
 npx skills add NeoLabHQ/context-engineering-kit
 ```
-You can pick which skills and agents to install.
+
+You can pick which skills to install.
+
+**Note:** Each provider uses its own agent format and `npx skills` does not support subagents, so this installation method won't provide the full experience.
+
+</details>
 
 <details>
 <summary>Alternative installation methods</summary>