Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation

--- description: Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation - Enforces strict isolation of Tauri 2.0 Inter-Process Communication (IPC) by scoping capabilities to explicit window labels and origins. Prohibits global wildcard capability bindings, mandating fine-grained access control lists (ACLs) to prevent untrusted or embedded webviews from executing privileged native host commands on mobile and desktop runtimes. globs: src-tauri/capabilities/**/*.json, src-tauri/src/**/*.rs, src/**/*.{ts,tsx} alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/tauri-v2-granular-ipc-capability-scoping" --- # Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation > **Severity**: CRITICAL | **Category**: mobile > **Anti-Pattern Warning**: Wildcard Window Scoping and Over-Permissioned IPC Capabilities in Multi-Window or Mobile Webview Contexts ## System Constraints You are a Principal Engineer enforcing Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation. You must ensure that all IPC permissions and native plugins are locked behind explicit, window-scoped capability manifests. Reject any configurations employing wildcard window selectors, unconfined remote origins, or overly broad plugin scopes like default filesystem or shell access. ## Strict Guidelines - Engineers MUST ALWAYS declare capability manifests under 'src-tauri/capabilities/' with explicit window identifiers instead of wildcards (never '"windows": ["*"]'). - Engineers MUST NOT grant filesystem, network, or shell permissions to secondary, OAuth, payment, or third-party webview contexts. - Code SHOULD restrict plugin permissions to granular sub-permissions (e.g., 'fs:allow-read-text-file' targeting '$APPDATA/*') rather than default broad scopes (e.g., 'fs:default'). - Services MUST verify calling webview context and cryptographic window identity in custom Rust commands using 'tauri::ipc::Request' or Window state before executing side-effects. - Components NEVER invoke raw shell execution or arbitrary path reads from the webview layer without strict path and argument validation. ## Bad vs Good Implementations ### Tauri 2.0 Capability Manifest Scoping #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Using wildcard '*' in 'windows' allows every webview context—including untrusted OAuth popups, ad frames, or compromised secondary windows—to invoke high-privilege filesystem and shell plugins. ```json { "$schema": "../gen/schemas/desktop-schema.json", "identifier": "default-capability", "description": "Capability for all webviews", "windows": ["*"], "permissions": [ "core:default", "fs:default", "shell:default" ] } ``` #### Production Standard (Correct) > **Standard**: Binds permissions strictly to the 'main' window label and scopes the filesystem permission down to only allow reading text files within the application's isolated AppData directory. ```json { "$schema": "../gen/schemas/desktop-schema.json", "identifier": "main-secure-capability", "description": "Fine-grained capability strictly bound to primary authenticated window", "windows": ["main"], "permissions": [ "core:default", { "identifier": "fs:allow-read-text-file", "allow": [{ "path": "$APPDATA/documents/*" }] } ] } ``` ### TypeScript IPC Client Context Verification #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Invoking IPC with unvalidated absolute paths assumes the ambient webview is authorized and bypasses client-side sanity checks against path traversal. ```typescript import { invoke } from '@tauri-apps/api/core'; export async function loadUserData(absolutePath: string): Promise<string> { // Anti-pattern: Unvalidated path and ambient trust in calling webview context return await invoke<string>('plugin:fs|read_text_file', { path: absolutePath }); } ``` #### Production Standard (Correct) > **Standard**: Validates that the current webview window matches the authorized capability label and ensures filename input conforms to a strict regex preventing path traversal. ```typescript import { invoke } from '@tauri-apps/api/core'; import { getCurrentWebviewWindow } from '@tauri-apps/api/webviewWindow'; const AUTHORIZED_WINDOW_LABEL = 'main'; const SAFE_FILE_PATTERN = /^[a-zA-Z0-9_-]+\.json$/; export async function loadUserData(fileName: string): Promise<string> { const currentWindow = getCurrentWebviewWindow(); if (currentWindow.label !== AUTHORIZED_WINDOW_LABEL) { throw new Error(`Security Violation: Window '${currentWindow.label}' is not authorized to invoke storage IPC.`); } if (!SAFE_FILE_PATTERN.test(fileName)) { throw new Error('Invalid file format: directory traversal and absolute paths are prohibited.'); } return await invoke<string>('plugin:fs|read_text_file', { path: `$APPDATA/documents/${fileName}` }); } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation

Tauri 2.0 Granular IPC Capability Scoping and ACL Isolation defines an industrial-grade behavioral standard for mobile engineering. Enforces strict isolation of Tauri 2.0 Inter-Process Communication (IPC) by scoping capabilities to explicit window labels and origins. Prohibits global wildcard capability bindings, mandating fine-grained access control lists (ACLs) to prevent untrusted or embedded webviews from executing privileged native host commands on mobile and desktop runtimes. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Wildcard Window Scoping and Over-Permissioned IPC Capabilities in Multi-Window or Mobile Webview Contexts Without an explicit system instruction file, developers spend hours debugging silent failures.

Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure Mode	AI Symptom (The Anti-Pattern)	Severity	Production Impact & Remedy
AI Hallucination & Deprecation Drift	Wildcard Window Scoping and Over-Permissioned IPC Capabilities in Multi-Window or Mobile Webview Contexts	Critical	Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production. Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture Inconsistency	AI assistants produce mixed paradigms across files, creating fragmented codebase conventions.	Medium	Increases cognitive load during code reviews and leads to maintenance debt across engineering teams. Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.

Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

Engineers MUST ALWAYS declare capability manifests under 'src-tauri/capabilities/' with explicit window identifiers instead of wildcards (never '"windows"

Engineers MUST ALWAYS declare capability manifests under 'src-tauri/capabilities/' with explicit window identifiers instead of wildcards (never '"windows": ["*"]').

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.