Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/duckduckgo/apple-browsers/shared-packagesgit clone --depth 1 https://github.com/duckduckgo/apple-browsersWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00000 | $0.01832 |
| Opus 5 | $0.00000 | $0.00916 |
| Sonnet 5 | $0.00000 | $0.00366 |
| Haiku 4.5 | $0.00000 | $0.00183 |
Grade A, and why
shared-packages scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 358 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Shared Packages Development Guidelines
Package Structure
Standard Package Layout
SharedPackages/
├── FeatureName/
│ ├── Package.swift
│ ├── README.md
│ ├── Sources/
│ │ └── FeatureName/
│ │ ├── Public/ # Public API
│ │ ├── Internal/ # Internal implementation
│ │ └── Resources/ # Assets and resources
│ └── Tests/
│ └── FeatureNameTests/
│ └── FeatureTests.swift
Package.swift Configuration
// swift-tools-version: 5.7
import PackageDescription
let package = Package(
name: "FeatureName",
platforms: [
.iOS(.v15),
.macOS(.v12)
],
products: [
.library(
name: "FeatureName",
targets: ["FeatureName"]
)
],
dependencies: [
// Only include truly necessary dependencies
.package(url: "https://github.com/DuckDuckGo/BrowserServicesKit", from: "1.0.0")
],
targets: [
.target(
name: "FeatureName",
dependencies: ["BrowserServicesKit"],
resources: [
.process("Resources")
]
),
.testTarget(
name: "FeatureNameTests",
dependencies: ["FeatureName"]
)
]
)
Cross-Platform Compatibility
Platform-Specific Code
#if os(iOS)
import UIKit
public typealias PlatformView = UIView
public typealias PlatformViewController = UIViewController
public typealias PlatformColor = UIColor
#elseif os(macOS)
import AppKit
public typealias PlatformView = NSView
public typealias PlatformViewController = NSViewController
public typealias PlatformColor = NSColor
#endif
// Use platform-agnostic types
public protocol CrossPlatformViewProtocol {
var backgroundColor: PlatformColor? { get set }
}
Conditional Compilation
public class FeatureManager {
public func performAction() {
#if os(iOS)
performIOSAction()
#elseif os(macOS)
performMacOSAction()
#endif
}
#if os(iOS)
private func performIOSAction() {
// iOS-specific implementation
}
#endif
#if os(macOS)
private func performMacOSAction() {
// macOS-specific implementation
}
#endif
}
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 358 lines · 0 tokens per session scan A 78c055c2eb7a
shared-packages is a cursor rule published in the GitHub repository duckduckgo/apple-browsers (252 stars, last pushed yesterday), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,832 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.
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