Imported from 1lck/Lithe-IDEA (.agents/skills/develop-lithe/SKILL.md). Install upstream with npx skills add 1lck/Lithe-IDEA --skill develop-lithe. Copyright stays with the author.

Develop Lithe

Follow these instructions for all work in this repository. Prefer the existing architecture, nearby code, and executable verification scripts over generic framework conventions.

Architecture decisions and trade-offs live in Chinese Agent Notes under .agents/notes/. For creating, migrating, updating, archiving, or reviewing those notes, load .agents/skills/agent-notes/SKILL.md.

Read the relevant source of truth

• Read the implementation and tests around a change before editing it.
• For ownership or dependency changes, read the relevant implemented Agent Note under .agents/notes/implemented/architecture/ and the relevant platform boundary document.
• For cross-platform behavior, read shared/contracts/application-boundary.md, shared/contracts/rust-core-api.md, and the related fixtures.
• For resizable panels, splitters, continuous dragging, or other high-frequency UI interaction, also read .agents/notes/implemented/architecture/2026-09-13-resizable-ui-performance-boundaries.md.
• Do not introduce a new architectural direction as part of an unrelated task.

Respect repository ownership

macOS is the current reference product. Windows is an independent React/Tauri implementation and must not import Swift source or depend on macOS types.

Preserve application boundaries

• Views receive AppModel or a dedicated feature model. They must not call the Rust C ABI, construct platform adapters, or depend on concrete workflow services.
• Application feature models own UI state transitions and coordinate user actions. Keep platform setup out of AppModel.
• Services orchestrate workflows through ports. They must not directly create Process, Pipe, FileManager, FileHandle, watchers, persistence stores, or concrete Mac* adapters.
• Core and application code must remain free of SwiftUI, AppKit, CoreServices, Tauri, WebView2, Win32, and concrete platform implementations.
• MacServiceContainer is the macOS composition root. Platform capabilities belong in macos/Sources/Lithe/Platform/MacOS/.
• Deterministic behavior shared by both products belongs in rust/lithe-core/. Native filesystem, process, terminal, runtime, security, persistence, and UI behavior belongs in platform adapters.
• Windows feature code must import @/platform/tauri-core instead of the Tauri core API directly. Shared operations route through lithe-core; Windows-only terminal, watcher, credential, process, and WebView behavior stays in the Tauri host or a platform plugin.

Keep shared contracts deterministic

• Use UTF-8 JSON for process and language boundaries.
• Use workspace-relative paths with / separators as identifiers. Absolute paths are allowed only in platform-owned diagnostics.
• Use one-based line numbers and null for missing locations.
• Keep lists and serialized results deterministically ordered.
• Represent asynchronous operations with explicit idle, loading, ready, and failed outcomes where the application contract requires them.
• Return stable error codes and user-facing messages. Put platform-specific details in the contract's details field.
• Preserve operationID, cancellation, timeout, and stale-result semantics for process-backed features.
• Add or update a shared fixture before a second platform relies on new shared behavior.
• Treat command names, JSON fields, error codes, and the C ABI as compatibility surfaces. Update contract documentation and every consumer when they change.

Follow the codebase's language conventions

Apply the style used by surrounding files. Prefer descriptive names, focused types and functions, explicit ownership, and straightforward control flow. Avoid unrelated cleanup, speculative abstractions, and new dependencies that the existing stack can reasonably avoid.

Swift and macOS

• Use the Swift 6.3.3 toolchain pinned in .swift-version (Xcode 26.6). The application target intentionally uses Swift 5 language mode while tests use Swift 6 language mode; do not change these modes as part of unrelated work.
• Put presentation in Views, feature state in Application, orchestration in Services, interfaces in Core ports, and native APIs in Platform/MacOS.
• Use the existing Swift Testing patterns under macos/Tests/LitheTests/.
• Keep platform-specific types from leaking through shared or application interfaces.

Rust

• Run cargo fmt and follow existing crate and module conventions.
• Keep shared results deterministic and preserve the JSON envelope and C ABI.
• Return structured failures across the boundary; do not expose unstable Rust implementation details as contract error codes.
• Add tests in the owning crate for changes to commands, parsing, validation, ordering, cancellation, or serialization.

Rust Core comments

Apply the following comment standard to first-party code under rust/lithe-core/. It does not require comment coverage in the database helpers, Windows/Tauri Rust crates, generated code, or third-party sources.

• Write comments in English and keep them accurate when behavior changes.
• Start each production module with a concise //! description of its responsibility or architectural boundary.
• Use /// for exported APIs, shared request and response types, core domain types, and C ABI functions. Document ownership and add # Safety for unsafe entry points; describe errors only when the failure contract is not obvious.
• Document enums, structs, variants, and fields whenever their names alone do not make their semantics, allowed values, units, ownership, or protocol role immediately clear. This requirement applies to internal types as well as exported contracts.
• Use // inside implementations to explain non-obvious decisions and constraints involving compatibility, determinism, ordering, security, performance, or cross-platform behavior.
• In tests, comment the scenario, regression risk, or boundary being protected when the test name and assertions do not make that intent clear.
• Do not narrate statements, restate descriptive names, or add comments to trivial accessors and straightforward control flow solely for coverage.
• Run ./scripts/verify-rust-core-comments.sh before slower Rust Core checks. It enforces module documentation, exported Rustdoc, English comments, and unsafe API safety sections without requiring documentation on every internal helper. Still review changed internal types and implementations for the semantic cases above, which a static check cannot judge reliably.

Windows React and Tauri

• Use Bun for frontend scripts and Tauri 2 for the Windows host. Keep React feature code in windows/tauri/src/features, reusable UI in windows/tauri/src/ui, the invoke boundary in windows/tauri/src/platform, and native Rust behavior in windows/tauri/src-tauri.
• Do not restore a parallel C++/Qt application layer or one Tauri command per shared Core operation. Translate compatibility command names through the central platform dispatcher.
• Add frontend tests for product behavior and Rust tests in the owning crate. Verify WebView2, ConPTY, installer, signing, and updater behavior on Windows.

Avoid hardcoded environment details

• Never commit credentials, tokens, private endpoints, signing material, or personal data.
• Do not embed developer-machine paths, workspace roots, home directories, temporary directories, or tool installation paths in application logic.
• Resolve executables, storage locations, and platform defaults through the appropriate adapter or configuration mechanism.
• Keep stable product constants named and centralized. Do not duplicate magic strings or numbers across platforms.
• Test fixtures may use clearly fake values, but must not contain real secrets or machine-specific paths.

Handle failures explicitly

• Do not silently discard errors. Return, translate, or log them at the layer that has enough context to act on them.
• Preserve stable contract error categories when crossing Rust, Swift, TypeScript, Tauri, or process boundaries.
• User-facing failures should be actionable without exposing credentials, environment contents, or unnecessary internal details.
• Comments should explain non-obvious constraints or decisions, not narrate the code.

Run validation that matches the change

Run the smallest relevant checks while iterating, then the broader affected set before handoff.

Also run tests for directly affected crates or targets. If the current machine cannot run a platform-specific check, state that clearly; do not claim an unexecuted check passed.

Keep changes reviewable

• Preserve existing uncommitted work and avoid modifying unrelated files.
• Do not commit generated output such as .build/, .swiftpm/, target/, dist/, DerivedData/, fixture build directories, or local IDE settings.
• Do not perform broad formatting or dependency updates as part of a focused fix.
• Do not use destructive Git commands, create commits, push branches, or change release metadata unless the task explicitly requests it.
• Update the owning Agent Note when behavior, ownership, or a compatibility surface changes. Do not rewrite notes for an implementation-only refactor that leaves the documented decision intact.

Complete the work honestly

Before reporting completion, confirm that the change is in the owning layer, relevant tests or verification scripts were run, shared consumers were checked, and no machine-specific hardcoding was introduced. Report what changed, what was verified, and any remaining platform or test limitations.