Agent skill

Compatibility and prerequisites

The skill supports fast-forward/container ^1.10 , PHP 8.3+ and Composer 2. Earlier library versions are outside its supported API contract. Its four examples cover configuration, composition, autowiring and provider resolution. The agent checks the application's installed versions before applying these instructions. A global copy does not upgrade dependencies or extend support to older versions; report a mismatch rather than silently upgrading the application.

composer install makes the bundled files available under vendor/fast-forward/container/resources/skills/fast-forward-container . The library declares extra.skills.source as resources/skills and suggests llm/skills as an optional installer. The directory uses the plural resources convention, recognized by that tool. Composer alone makes the files available; the consumer chooses automatic synchronization or an explicit copy. Keep the complete skill directory so relative resource links remain valid.

Choose an installation scope

Prefer project-local installation for a team. Record the source version/reference and review updates with the project's library version. composer.lock pins the installed library. With the optional plugin, commit its configuration and review any changes to committed generated copies. With a manual or Skills CLI copy, commit the installed skill alongside the application; those copies do not refresh automatically. Use one installation mechanism for a given skill so an automatic sync does not overwrite a manually maintained copy.

Use global installation when a developer wants the skill across projects. That copy has an independent update lifecycle and must still inspect each project's Composer version. Avoid duplicate local/global copies with conflicting instructions; agent precedence varies, so keep one effective copy per host.

Discovery paths depend on the agent:

These are default paths; honor an agent's configured home and current discovery rules. Other Agent Skills-compatible hosts may use different paths. The skill itself has no dependency on a specific agent or discovery adapter.

Automatic project installation with Composer

The optional llm/skills Composer plugin discovers the library's metadata and copies the complete skill directory into the consumer project. It is suggested, not required: installing this library does not install or authorize the plugin. The configuration below uses llm/skills ^1.15 .

Before installing or enabling the plugin, prepare skills.json at the application root so your choices apply to its first automatic sync. For an existing file, merge the fields below while preserving unrelated settings and intentional aliases; do not replace the whole configuration with this example:

{
  "target": ".agents/skills",
  "aliases": [],
  "discovery": false,
  "auto-sync": true,
  "vendor-sources": false,
  "dependencies": {
    "composer": {
      "trusted": ["fast-forward/container"],
      "trusted-replace": true
    }
  }
}

This selects only this library's declared skill without adding the tool's built-in or direct-dependency trust defaults. A team deliberately trusting all Fast Forward donor packages may choose fast-forward/* instead. vendor-sources: false disables remote skill sources advertised by dependencies. aliases: [] makes the default without extra host links explicit; preserve any intentional aliases already configured in the project. Choose .claude/skills as the target for a Claude Code-only project; the destination belongs to the application, not the library.

Then install the tool as a development dependency:

composer require --dev llm/skills:^1.15
composer skills:show

Review and authorize llm/skills when Composer asks. For non-interactive installs, merge that specific authorization into the application's existing composer.json after approving the plugin:

{
  "config": {
    "allow-plugins": {
      "llm/skills": true
    }
  }
}

Keep existing plugin authorizations and commit composer.json , composer.lock and skills.json . Subsequent composer install and composer update runs synchronize accepted skills automatically; no library script or application hook is needed. --no-plugins prevents the plugin from loading. With Composer 2.10.3 and plugin 1.15.0, --no-scripts alone still allowed the plugin's automatic sync; do not rely on it to disable this feature. Set auto-sync to false to use only explicit commands:

composer skills:update fast-forward/container --dry-run
composer skills:update fast-forward/container

An explicit package name on that command also grants trust for that run, even if the package is absent from the configured allowlist. The named command can discover a skill without metadata; the automatic route above requires declared metadata because discovery is disabled.

The plugin copies files and does not prove an agent has loaded the skill. Inspect the result, refresh the agent session and confirm discovery. Installing the Composer tool globally makes its commands available across projects; it does not install this skill into the agent's global directory. Use the explicit global copy or Skills CLI route below when that is the intended scope.

composer skills:update --clean --dry-run

Copy from the installed library

From the consumer project root, select a source and one destination:

skill_source="vendor/fast-forward/container/resources/skills/fast-forward-container"
skill_target=".agents/skills/fast-forward-container"
# Global Codex alternative:
# skill_target="$HOME/.agents/skills/fast-forward-container"
# For Claude Code use .claude/skills instead.

test -f "$skill_source/SKILL.md" &&
test ! -e "$skill_target" &&
test ! -L "$skill_target" &&
mkdir -p "$(dirname "$skill_target")" &&
cp -R "$skill_source" "$skill_target"

The command refuses an existing destination, including a dangling symlink. If the source is missing, check the installed library version and package contents before continuing. Do not create a placeholder SKILL.md or silently upgrade production dependencies to install agent instructions.

Inspect the copied entrypoint and resources, then refresh the agent session and confirm the skill appears in its available skills. For an explicit activation, ask the agent to use fast-forward-container to configure the application. Installation alone does not prove that an agent has loaded the skill.

Update, removal and rollback for a copy

Record the new source version/reference and review the diff before an update. Move the old package to a fresh backup path outside every skill discovery directory , then repeat the guarded copy command. For example, after choosing the same skill_target :

skill_backup="$HOME/.agent-skill-backups/fast-forward-container-$(date +%Y%m%d%H%M%S)-$$"
test -d "$skill_target" &&
test ! -L "$skill_target" &&
test ! -e "$skill_backup" &&
test ! -L "$skill_backup" &&
mkdir -p "$(dirname "$skill_backup")" &&
mv "$skill_target" "$skill_backup"

The command requires a real skill directory and refuses an existing backup, including a dangling symlink. Record the backup path before installing a replacement. Moving it out also removes a manually installed copy from discovery. Refresh the agent session. To roll back, archive any replacement to a different backup path first and move the saved directory back to its original destination. Keep LICENSE and all references with the package; do not archive old copies inside .agents/skills or .claude/skills , where they may remain discoverable.

Assisted installation with Skills CLI

The optional Skills CLI supports both scopes and agent-specific paths. The commands use skills@1.7.2 , which requires Node.js 22.20.0+. Repository-source installation also requires Git. The CLI is a development tool, not a PHP runtime dependency.

For a bundled source in the current project:

npx --yes skills@1.7.2 add ./vendor/fast-forward/container/resources/skills/fast-forward-container --skill fast-forward-container --agent codex --copy --yes
npx --yes skills@1.7.2 list --agent codex

Add --global to add and list for a global installation. Replace --agent codex with --agent claude-code for Claude Code. The explicit --copy avoids symlinks into a vendor directory that Composer may replace.

To pin instructions separately, set SKILL_REF to a full commit SHA from the library version used by the project , then use:

npx --yes skills@1.7.2 add "https://github.com/php-fast-forward/container/tree/$SKILL_REF/resources/skills/fast-forward-container" --skill fast-forward-container --agent codex --copy --yes

Record that SHA with the application. A branch name can move. To update a pinned installation, repeat add with the newly reviewed source/revision and inspect the resulting diff. An unqualified update-to-latest is not the same as a pinned upgrade. Commit project copies and any lockfile generated by the CLI.

Remove only this skill with:

npx --yes skills@1.7.2 remove fast-forward-container --agent codex --yes
# For the global installation:
npx --yes skills@1.7.2 remove fast-forward-container --agent codex --global --yes

Other Composer tooling

netresearch/composer-agent-skill-plugin can discover library-provided metadata or explicitly configured direct sources, manage trust and generate an AGENTS.md index. This is a useful option for teams already choosing that workflow, but it executes as a Composer plugin and changes project instruction files. It is not required by this library and no automatic registration hook is enabled here.

Version 2.1.1 requires PHP 8.4, so it does not cover the full PHP 8.3 range supported here. If a project adopts it separately, review its version, allow-plugins/trust policy and generated-instruction ownership.