Tauri 2.0 Capability-Based IPC Permission Isolation and Payload Validation

--- description: Tauri 2.0 Capability-Based IPC Permission Isolation and Payload Validation - Enforces Tauri 2.0 granular capability definitions, strict Access Control Lists (ACLs), and runtime schema validation on all native IPC bridges. Eliminates arbitrary code execution and unauthorized native API exposure when operating on mobile and embedded WebViews. Prevents privilege escalation by scoping permissions exclusively to designated windows and verifying command payloads against typed boundaries. 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-2-capability-ipc-permission-isolation-standard" --- # Tauri 2.0 Capability-Based IPC Permission Isolation and Payload Validation > **Severity**: CRITICAL | **Category**: mobile > **Anti-Pattern Warning**: Assigning global wildcard permissions in capabilities and invoking unvalidated native commands across arbitrary WebViews ## System Constraints You are a Principal Security Architect enforcing the Tauri 2.0 Capability-Based IPC Permission Isolation Standard. You mandate zero-trust IPC scoping between mobile WebViews and Rust native layers. Reject all wildcard plugin permissions, enforce window-level capability containment, and require strict compile-time and runtime payload validation for every invoked bridge command. ## Strict Guidelines - Engineers MUST ALWAYS define granular capabilities per window context inside `src-tauri/capabilities/*.json` rather than granting blanket default permissions. - Engineers MUST NOT use wildcard permissions (e.g., `core:default`, `fs:default`, `shell:all`) in production capability manifests for mobile platforms. - Code SHOULD validate all IPC payloads on the frontend using runtime schema parsers (such as Zod) before invoking the Tauri bridge. - Services MUST implement native Rust command argument validation using strictly typed structs derived with `serde::Deserialize` and reject path traversal or un-sanitized arguments. - Components NEVER execute raw, untyped `invoke()` calls directly inside UI elements; all IPC calls MUST be routed through a centralized, typed client gateway. ## Bad vs Good Implementations ### Typed IPC Gateway with Schema-Guarded Tauri 2.0 Invocations #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Directly invokes internal native plugins with unchecked user inputs, exposing the application to path traversal and arbitrary filesystem overwrite if the web context is compromised. ```typescript import { invoke } from '@tauri-apps/api/core'; // ANTI-PATTERN: Direct untyped invoke with unvalidated input bypassing capability boundaries export async function saveUserData(filePath: string, content: string): Promise<void> { // Arbitrary path injection risk: Webview can access restricted mobile sandbox directories await invoke('plugin:fs|write_file', { path: filePath, contents: Array.from(new TextEncoder().encode(content)) }); } ``` #### Production Standard (Correct) > **Standard**: Validates payload structures at the boundary before passing parameters to a domain-specific Rust command mapped directly to scoped Tauri 2.0 capabilities. ```typescript import { invoke } from '@tauri-apps/api/core'; import { z } from 'zod'; const SafeWritePayloadSchema = z.object({ filename: z.string().regex(/^[a-zA-Z0-9_-]+\.json$/, 'Invalid filename format'), payload: z.record(z.unknown()) }); type SafeWritePayload = z.infer<typeof SafeWritePayloadSchema>; // PRODUCTION INVARIANT: Validated payload routed through a dedicated, capability-scoped native command export async function persistSecureState(data: SafeWritePayload): Promise<{ success: boolean }> { const validated = SafeWritePayloadSchema.parse(data); return await invoke<{ success: boolean }>('save_application_state', { filename: validated.filename, content: JSON.stringify(validated.payload) }); } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tauri 2.0 Capability-Based IPC Permission Isolation and Payload Validation

Tauri 2.0 Capability-Based IPC Permission Isolation and Payload Validation defines an industrial-grade behavioral standard for mobile engineering. Enforces Tauri 2.0 granular capability definitions, strict Access Control Lists (ACLs), and runtime schema validation on all native IPC bridges. Eliminates arbitrary code execution and unauthorized native API exposure when operating on mobile and embedded WebViews. Prevents privilege escalation by scoping permissions exclusively to designated windows and verifying command payloads against typed boundaries. 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: Assigning global wildcard permissions in capabilities and invoking unvalidated native commands across arbitrary WebViews 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	Assigning global wildcard permissions in capabilities and invoking unvalidated native commands across arbitrary WebViews	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 define granular capabilities per window context inside `src-tauri/capabilities/*.json` rather than granting blanket default permissions.

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.