dart-use-ffigen skill: generate Dart FFI bindings with package:ffigen

Makes your agent generate Dart bindings for C code with package:ffigen instead of writing them by hand.

Installs: 14.8K; on skills.sh
Stars: 3.1K; on GitHub
Updated: Nov 2026; last repo commit

This skill tells your agent never to hand-write FFI bindings when C headers exist. It adds ffigen as a dev dependency, writes a generator script at tool/ffigen.dart, runs it, and checks the result with dart analyze.

It triggers on writing new FFI bindings, extending C, Objective-C or Swift integrations, or replacing hand-crafted dart:ffi code. It sets rules for where headers and output go, adds a license preamble to generated files, and turns on usage recording so unused native code can be stripped.

Good for

Dart and Flutter developers wrapping a C library
Package authors replacing hand-written dart:ffi lookups
Teams that want generated bindings licensed and placed consistently

Install dart-use-ffigen

Claude Code

Copy this prompt.

Install the dart-use-ffigen skill in Claude Code. Run this command:

claude plugin marketplace add flutter/agent-plugins
claude plugin install dart-flutter@dart-flutter

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Plugin route (Flutter docs): adds all 25 skills the repo has, not only this one, plus the Dart MCP server from the plugin manifest, which runs dart mcp-server. The docs say plugins do not load Flutter rules automatically. Single-skill route: the skills CLI command adds only this skill. Either way the project needs the Dart SDK.

From the vendor's docs. Source.

What's in the skill

When it loads

Guide agents to use `package:ffigen` to automatically generate FFI bindings instead of writing them manually. Use this skill when a task involves writing new FFI bindings, extending C/Objective-C/Swift integrations, or replacing hand-crafted `dart:ffi` setups.

Sections in SKILL.md

Contents
Introduction
Constraints
FFIgen Overview
1. FfiGenerator
2. Headers
3. Functions
4. Output
Step-by-Step Workflow
Step 1: Check/Add Dependencies
Step 2: Formulate Paths Dynamically
Step 3: Write the Script (tool/ffigen.dart)
Step 4: Run Code Generation
Step 5: Static Analysis
Concrete Example: Binding a C Library
The C Header File (third_party/sqlite/sqlite3.h)

Key facts

Author: Flutter team (flutter/agent-plugins; the README says the plugins are maintained by the Flutter team)
Repo: flutter/agent-plugins, folder skills/dart-use-ffigen
Installs on skills.sh: 14,842 as of 2 Nov 2026
GitHub stars: 3,136 for the whole flutter/agent-plugins repo, 2 Nov 2026
License: BSD-3-Clause
Last commit in the repo: 2026-11-01
What is inside: 1 file (SKILL.md only)
skills.sh audits: Gen Agent Trust Hub pass, Socket pass, Snyk pass
Needs: A Dart package with C headers; the Dart SDK for dart pub add, dart run and dart analyze

What it includes

Rules for where headers, the generator and output files live
No hand-written bindings when headers exist. Generator at tool/ffigen.dart, third-party headers in third_party/, output under lib/src/third_party/ with a .g.dart extension, and only the symbols you need.
Read · Constraints
Runs dart pub add dev:ffigen
Checks pubspec.yaml for ffigen in dev_dependencies and adds it with the Dart CLI if it is missing.
Runs code · Add the dependency
Creates the generator script with FfiGenerator
Resolves paths from Platform.script so it runs from any folder, sets the entry header, an include filter, a license preamble, and recordUse so unused functions can be tree-shaken.
Write · Write tool/ffigen.dart
Runs dart run tool/ffigen.dart
Generates the .g.dart bindings file, and a record-use mapping file when the package builds native assets.
Try: “Replace the hand-written dart:ffi bindings for sqlite3.h with generated ones.”
Runs code · Run the generator
Runs dart analyze and checks the checklist
Lint warnings in generated code are silenced through the preamble. Real compile errors are reported to you to file with dart-lang/native, not fixed by editing the generated file.
Runs code · Analyze and verify

From the official docs

Permissions

Low risk

What it can do

Read your data
Create and change things
Delete things
Read-only mode

Watch out for

It runs a generator script in your package
dart run tool/ffigen.dart executes Dart code the agent wrote and parses your C headers. Read the script before the first run. github.com
It adds a dev dependency
dart pub add dev:ffigen changes pubspec.yaml and fetches from pub.dev. Check the diff before committing. github.com
The plugin route adds an MCP server and 25 skills
The dart-flutter Claude plugin manifest declares one MCP server, dart-mcp-server, started with `dart mcp-server`, and has no hooks field. The repo also has .agents/hooks.json with Stop hooks that call dart format and dart analyze scripts; the manifest does not reference it. github.com

Technical details

Turning on read-only	The SKILL.md defines no read-only switch.
Talks to	pub.dev, when dart pub add fetches ffigen
Scopes	Edits pubspec.yaml through dart pub add Writes tool/ffigen.dart and files under lib/src/third_party/ Runs dart run tool/ffigen.dart and dart analyze

Questions

What does the dart-use-ffigen skill do?

It makes your agent generate Dart FFI bindings with package:ffigen instead of writing dart:ffi lookups by hand. It sets up a generator script, runs it, and verifies the output with dart analyze.

How do I install it?

Use the install box on this page. It is a single SKILL.md, so adding the skill folder is the whole install. Your project then needs the Dart SDK.

How is it different from dart-setup-ffi-assets?

This skill generates the Dart bindings from C headers. The sibling dart-setup-ffi-assets skill in the same repo compiles or bundles the C code itself with build and link hooks, and its SKILL.md uses FFIgen for the symbol mapping.

Will it edit the generated bindings by hand?

No. If dart analyze shows real errors in the generated file, the SKILL.md says not to edit it. The agent reports the details so you can file an issue at dart-lang/native.

Is it safe to run?

It adds a dev dependency, writes a generator script and generated files in your package, and runs dart commands. Review the diff before you commit. The Watch out list has the details.

Information

updated Nov 2, 2026

Repository: flutter/agent-plugins
Folder: skills/dart-use-ffigen

flutter/agent-plugins skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 5

Flutter docs: Get started developing with AI · docs.flutter.dev
flutter/agent-plugins README · github.com
dart-flutter Claude plugin manifest · github.com
dart-use-ffigen SKILL.md · github.com
dart-setup-ffi-assets SKILL.md · github.com