Generated banner for Appfunctions
Generated logo for Appfunctions

Appfunctions

Android (Google)OfficialCreated by Google LLCDistributed by Android (Google)

  • Skill
  • Tool integration
  • Software development
  • Apache-2.0
  • No issues found

From the author

Analyzes Android apps to find user workflows to expose as AppFunctions, such as creating a note, playing media, or sending a message. AI agents, voice commands, and system shortcuts then run them without opening the app UI. Generates Kotlin code with the androidx.appfunctions library, and refines KDoc and the app description so that agents choose and call functions correctly. Use this skill when discovering, implementing, documenting, testing, or upgrading AppFunctions in an Android app, including @AppFunctionDeclaration, @AppFunctionSerializable, @AppFunctionServiceEntryPoint, AppFunctionService, app_metadata.xml, appfn:instructions, adb shell cmd app_function, and legacy @AppFunction or AppFunctionConfiguration.Provider code. Don't use for building agents that call AppFunctions or for remote MCP servers.
— the description by Google LLC

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

The appfunctions skill provides a structured approach to exposing Android app workflows as AppFunctions. It covers the full development lifecycle, including feature discovery, Kotlin implementation using the androidx.appfunctions library, KDoc optimization for AI agents, and local testing via ADB. It ensures developers can build modular, secure, and discoverable tools that allow AI agents, voice commands, and system shortcuts to interact with app functionality without requiring the user to open the app UI.

What it does

  • Analyzes Android codebases to identify workflows suitable for AppFunctions.
  • Generates Kotlin code using the androidx.appfunctions library and KSP.
  • Refines KDoc and app metadata to improve AI agent understanding and tool selection.
  • Provides ADB commands for listing, executing, and managing AppFunction states.
  • Supports migration from legacy AppFunction APIs to the modern Service Entry Point architecture.
  • Enforces security constraints to ensure only safe, non-destructive tasks are exposed.

When to use it

  • When you need to expose app features to AI agents or system-level voice commands.
  • When implementing or upgrading to the latest androidx.appfunctions library.
  • When you need to optimize existing function descriptions for better LLM or MCP compatibility.
  • When testing or debugging AppFunction registration and execution on a local device or emulator.
  • When migrating legacy AppFunction implementations to the current service entry point pattern.

Advantages

  • Enables seamless, UI-less interaction between AI agents and Android applications.
  • Standardizes the implementation process through clear, step-by-step development workflows.
  • Improves discoverability and reliability of app tools for AI models.
  • Provides robust testing capabilities via direct ADB command integration.
  • Ensures backward compatibility through the use of Jetpack libraries.

Usage examples

“Analyze my app to find features that should be exposed as AppFunctions.”
The agent will perform a feature discovery analysis, identifying key user workflows and recommending which should be implemented as AppFunctions.
“How do I implement a 'send message' AppFunction in my Kotlin project?”
The agent will guide you through generating the necessary Kotlin code, configuring the service entry point, and adding the required annotations.
“Optimize my AppFunction KDocs so an AI agent knows how to use them.”
The agent will review your existing KDoc and app metadata, providing refinements to ensure clear, intent-based descriptions for AI models.
“List all registered AppFunctions on my device for package com.example.app.”
The agent will provide the specific ADB command to query and display the registered functions for your application.

Install

  1. Download the skill as a ZIP:

    https://autogineer.com/agent-skills/android/appfunctions/download
  2. Unzip it into the cross-client skills folder of your project:

    mkdir -p .agents/skills && unzip appfunctions.zip -d .agents/skills

Documentation by Google LLC

Analyzes Android apps to identify key user workflows to expose as AppFunctions, such as creating a note, playing media, or sending a message, for AI agents, voice commands, and system shortcuts to run without opening the app UI.

Generates Kotlin code to expose these workflows to the Android system, allowing agents to discover and execute them on-device.

Also refines KDoc documentation and the app description so AI agents correctly understand and use the provided functionality.

Prerequisites

The app must targetSdk 36 or newer and use compileSdk 37 or newer as AppFunctions, part of the Android platform API, are available from Android 16 onwards. Always use the Jetpack library because it handles backward compatibility. Use androidx.appfunctions:appfunctions and the KSP compiler androidx.appfunctions:appfunctions-compiler, version 1.0.0-beta01 or later.

Workflows

This skill enables the caller to discover features that will be provided to system agents, implement these with AppFunctions, improve function description for agents, and use ADB commands for local evaluation and testing.

The full AppFunction development flow consists of these four steps:

  • Step 1: Discovery: Analyze Android codebases to identify and recommend potential AppFunctions. Use this step when a user asks to "discover AppFunctions," "find features for AI," or "analyze my app for agentic tools."

  • Step 2: Implementation and configuration: Generate Kotlin implementations of AppFunctions, manage system-wide configuration, and configure build dependencies. Use this step when a user asks to "implement AppFunctions," "set up the AppFunctions framework," or "configure Hilt for AppFunctions."

  • Step 3: KDoc refinement: Optimize AppFunction KDoc and the app description for AI agents and Model Context Protocol. If a user asks to "write KDoc", "optimize for MCP", or "refactor tool descriptions for LLMs", use this step.

  • Step 4: Testing and debugging: Provide commands to interact with AppFunctions using ADB for testing and debugging. If a user wants to "list app functions", "invoke an app function", or "verify app function registration" on a device, use this step.

When the user asks for a subset of the steps, run those steps and any step that the critical constraints require. Then list the skipped steps and ask whether to run them.

If they apply, you must load the following references:

  • Context and terminology: Defines the ubiquitous language, architecture definitions, and design patterns across the AppFunctions skill suite. Load when you need to understand core architecture terminology or check the distinctions between modern and legacy AppFunctions APIs.

  • Migration to service entry point : Migrates apps on AppFunctions 1.0.0-alpha09 or lower to the AppFunctionServiceEntryPoint architecture from 1.0.0-alpha10, and upgrades apps to 1.0.0-beta01. Load it when a user asks to migrate or upgrade existing AppFunctions code. When you find legacy AppFunctionConfiguration.Provider implementations, @AppFunction annotations, or appfn:description attributes, load it and ask the user before you migrate.

Critical constraints

  • Modular consistency: You must refine KDocs immediately after you generate AppFunction implementations.

  • Security: Expose only safe, non-destructive tasks that the app's UI already offers on that form factor. Never give agents wide-ranging access to user data or system resources. Never require or return passwords, financial details, private keys, or other highly sensitive personal information.

  • Descriptions: Describe what each function does, never how an agent must behave. Put call order across functions in the app description, not in function KDoc.

Troubleshooting

Files

LICENSE


                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).

      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

   END OF TERMS AND CONDITIONS

   APPENDIX: How to apply the Apache License to your work.

      To apply the Apache License to your work, attach the following
      boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Security

No issues found by our static scan· No issues found

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Created by
Google LLC
Publisher
Android (Google) (Official)
Distributed by
Android (Google)
Source
android/skills · device-ai/appfunctions · commit bf68e2d
Licence
Apache License 2.0 (redistribution allowed)
  • LICENSE (added by AutoGineer from LICENSE.txt)
  • ATTRIBUTION.md (written by AutoGineer)
Synced

AutoGineer is not affiliated with or endorsed by Google LLC or Android (Google).

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download appfunctions.zip