capacitor-plugin-spm-support

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Guides the agent through adding Swift Package Manager (SPM) support to an existing Capacitor plugin. Covers creating a Package.swift manifest, replacing Objective-C bridge files with the CAPBridgedPlugin Swift protocol, updating .gitignore for SPM artifacts, cleaning up the Xcode project file, and updating package.json. Do not use for Capacitor app projects, creating new plugins from scratch, or non-Capacitor plugin frameworks.

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NPX Install

npx skill4agent add capawesome-team/skills capacitor-plugin-spm-support

Add SPM Support to a Capacitor Plugin

Add Swift Package Manager (SPM) support to an existing Capacitor plugin by replacing the Objective-C bridge with the
CAPBridgedPlugin
Swift protocol and adding a
Package.swift
manifest.

Prerequisites

RequirementVersion
Capacitor6+
Swift5.9+
Xcode15+
The project must be a Capacitor plugin (not an app project). The plugin must have an existing iOS implementation with Swift source files in
ios/Plugin/
.

Procedures

Step 1: Gather Plugin Information

  1. Read
    package.json
    in the plugin root. Extract:
    • The plugin package name (e.g.,
      @capawesome/capacitor-app-review
      ).
    • The existing
      files
      array entries.
    • The existing
      scripts
      entries.
  2. Read the
    .podspec
    file in the plugin root. Extract:
    • The pod name (the
      Pod::Spec.new
      argument, e.g.,
      CapawesomeCapacitorAppReview
      ). This becomes the SPM package name.
    • The iOS deployment target from
      s.ios.deployment_target
      (e.g.,
      '13.0'
      ). Extract the major version number (e.g.,
      13
      ). This becomes the SPM iOS version.
    • All third-party CocoaPods dependencies — any
      s.dependency
      or
      spec.dependency
      entries that are not
      Capacitor
      or
      CapacitorCordova
      . Record each dependency name and version constraint.
  3. Identify the plugin Swift file in
    ios/Plugin/
    . It contains a class extending
    CAPPlugin
    with
    @objc(<PluginClassName>)
    . Extract:
    • The plugin class name (e.g.,
      AppReviewPlugin
      ).
    • The JavaScript name from the Objective-C
      .m
      file's
      CAP_PLUGIN
      macro first string argument (e.g.,
      AppReview
      ).
    • All plugin methods from
      CAP_PLUGIN_METHOD
      macro calls in the
      .m
      file, noting each method's name and return type (e.g.,
      CAPPluginReturnPromise
      ).
  4. Identify the Objective-C bridge files in
    ios/Plugin/
    :
    • <PluginClassName>.h
      (header file)
    • <PluginClassName>.m
      (implementation file with
      CAP_PLUGIN
      macro)
  5. Read the Capacitor peer dependency version from
    package.json
    (
    peerDependencies["@capacitor/core"]
    ). Determine the major version (e.g.,
    6
    ). This is the Capacitor major version.

Step 2: Resolve CocoaPods Dependencies for SPM

Skip this step if no third-party CocoaPods dependencies were found in Step 1.
For each third-party CocoaPods dependency, an equivalent SPM-compatible package is needed. Present the list of dependencies to the user and ask whether they can provide the SPM package URLs themselves, or whether the agent should search the web for SPM equivalents.
If the user provides SPM package URLs: Record them and proceed to Step 3.
If the user requests a web search: For each CocoaPods dependency:
  1. Search the web for
    "<dependency_name>" Swift Package Manager
    to determine whether the original CocoaPods dependency also supports SPM. Many popular libraries (e.g., Firebase, Alamofire) distribute via both CocoaPods and SPM from the same repository.
  2. If the original library supports SPM, use its Git repository URL. Use the same version as specified in the podspec — convert the CocoaPods version constraint to the SPM equivalent (e.g.,
    ~> 5.0
    becomes
    .upToNextMajor(from: "5.0.0")
    ,
    = 2.1.0
    becomes
    .exact("2.1.0")
    ).
  3. If the original library does not support SPM, search for
    "<dependency_name>" SPM alternative
    to find a replacement package that provides equivalent functionality via SPM. Use a version that is compatible with the version used in the podspec.
  4. If no SPM-compatible alternative exists, inform the user and ask how to proceed.
Record the resolved SPM package URL, version requirement, and product name(s) for each dependency. These will be added to
Package.swift
in the next step.

Step 3: Create
Package.swift

Create
Package.swift
in the plugin root directory with the following content:
swift
// swift-tools-version: 5.9
import PackageDescription

let package = Package(
    name: "<SPM_PACKAGE_NAME>",
    platforms: [.iOS(.v<SPM_IOS_VERSION>)],
    products: [
        .library(
            name: "<SPM_PACKAGE_NAME>",
            targets: ["<PLUGIN_CLASS_NAME>"])
    ],
    dependencies: [
        .package(url: "https://github.com/ionic-team/capacitor-swift-pm.git", branch: "<CAPACITOR_MAJOR_VERSION>.0.0")
        // <ADDITIONAL_PACKAGE_DEPENDENCIES>
    ],
    targets: [
        .target(
            name: "<PLUGIN_CLASS_NAME>",
            dependencies: [
                .product(name: "Capacitor", package: "capacitor-swift-pm"),
                .product(name: "Cordova", package: "capacitor-swift-pm")
                // <ADDITIONAL_TARGET_DEPENDENCIES>
            ],
            path: "ios/Plugin"),
        .testTarget(
            name: "<PLUGIN_CLASS_NAME>Tests",
            dependencies: ["<PLUGIN_CLASS_NAME>"],
            path: "ios/PluginTests")
    ]
)
Replace all placeholders:
  • <SPM_IOS_VERSION>
    — the SPM iOS version from Step 1 (e.g.,
    13
    ).
  • <SPM_PACKAGE_NAME>
    — the pod name from Step 1 (e.g.,
    CapawesomeCapacitorAppReview
    ).
  • <PLUGIN_CLASS_NAME>
    — the plugin class name from Step 1 (e.g.,
    AppReviewPlugin
    ).
  • <CAPACITOR_MAJOR_VERSION>
    — the Capacitor major version from Step 1 (e.g.,
    6
    ).
  • <ADDITIONAL_PACKAGE_DEPENDENCIES>
    — if third-party dependencies were resolved in Step 2, add a
    .package(url: "<repo_url>", <version_requirement>)
    entry for each. Remove the comment line if no extra dependencies exist.
  • <ADDITIONAL_TARGET_DEPENDENCIES>
    — for each package dependency added above, add a corresponding
    .product(name: "<ProductName>", package: "<package-name>")
    entry. Remove the comment line if no extra dependencies exist.

Step 4: Update the Swift Plugin Class

Open the plugin Swift file (e.g.,
ios/Plugin/<PluginClassName>.swift
).
  1. Add
    CAPBridgedPlugin
    protocol conformance to the class declaration.
  2. Add the three required properties as the first properties in the class body, before any existing properties.
Apply this diff pattern:
diff
 @objc(<PluginClassName>)
-public class <PluginClassName>: CAPPlugin {
+public class <PluginClassName>: CAPPlugin, CAPBridgedPlugin {
+    public let identifier = "<PluginClassName>"
+    public let jsName = "<JS_NAME>"
+    public let pluginMethods: [CAPPluginMethod] = [
+        CAPPluginMethod(name: "<method1>", returnType: CAPPluginReturnPromise),
+        CAPPluginMethod(name: "<method2>", returnType: CAPPluginReturnPromise)
+    ]
Replace:
  • <PluginClassName>
    — the plugin class name (e.g.,
    AppReviewPlugin
    ).
  • <JS_NAME>
    — the JavaScript name from the
    .m
    file's
    CAP_PLUGIN
    macro (e.g.,
    AppReview
    ).
  • The
    pluginMethods
    array — list all methods from the
    .m
    file's
    CAP_PLUGIN_METHOD
    calls, preserving each method's name and return type exactly.

Step 5: Delete Objective-C Bridge Files

Delete the following files from
ios/Plugin/
:
  • <PluginClassName>.h
  • <PluginClassName>.m
These are no longer needed because the plugin registration is now handled by the
CAPBridgedPlugin
protocol in Swift.

Step 6: Clean Up the Xcode Project File

Open
ios/Plugin.xcodeproj/project.pbxproj
and remove all references to the deleted Objective-C files. Specifically, remove lines referencing:
  • <PluginClassName>.h
    — file references, build phase entries (
    PBXBuildFile
    ,
    PBXFileReference
    ,
    PBXGroup
    children,
    PBXHeadersBuildPhase
    )
  • <PluginClassName>.m
    — file references, build phase entries (
    PBXBuildFile
    ,
    PBXFileReference
    ,
    PBXGroup
    children,
    PBXSourcesBuildPhase
    )
Search for both filenames in the
.pbxproj
file and remove every line that references them.

Step 7: Update
.gitignore

Open
.gitignore
in the plugin root. Add the following entries if not already present:
diff
 # iOS files
+Package.resolved
+/.build
+/Packages
+.swiftpm/configuration/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc
Place these entries in the iOS section of the
.gitignore
file, after any existing iOS-related entries (e.g.,
Pods
,
Podfile.lock
).

Step 8: Update
package.json

Apply two changes to
package.json
:
  1. Add
    "Package.swift"
    to the
    files
    array:
diff
     "ios/Plugin/",
-    "<PodName>.podspec"
+    "<PodName>.podspec",
+    "Package.swift"
   ],
  1. Add the
    ios:spm:install
    script to the
    scripts
    object:
diff
     "ios:pod:install": "cd ios && pod install --repo-update && cd ..",
+    "ios:spm:install": "cd ios && swift package resolve && cd ..",
If the
ios:pod:install
script does not exist, add the
ios:spm:install
script after the last existing script entry.

Step 9: Verify

  1. Run
    npm install
    in the plugin root to ensure
    package.json
    is valid.
  2. Verify the iOS build still succeeds by building the plugin's example or test app.

Error Handling

  • If the
    .pbxproj
    file becomes corrupted after removing ObjC references, restore it from version control and carefully re-edit, ensuring only complete lines are removed.
  • If the Swift build fails with
    CAPBridgedPlugin
    not found, verify that
    @capacitor/core
    is version 6+ and that
    capacitor-swift-pm
    branch matches the Capacitor major version.
  • If SPM resolution fails (
    swift package resolve
    ), verify the
    Package.swift
    target paths match the actual directory structure (
    ios/Plugin
    for sources,
    ios/PluginTests
    for tests).
  • If the plugin has no test target directory (
    ios/PluginTests
    ), remove the
    .testTarget
    block from
    Package.swift
    .
  • If the plugin has additional Swift source files beyond the main plugin file, no extra changes are needed — SPM automatically includes all
    .swift
    files in the target path.
  • If the
    .m
    file uses
    CAPPluginReturnNone
    instead of
    CAPPluginReturnPromise
    for some methods, preserve the original return type in the
    pluginMethods
    array.
  • If a CocoaPods dependency has no SPM equivalent and no alternative can be found, the plugin cannot fully support SPM. Inform the user and suggest they either vendor the dependency source or wait for upstream SPM support.