Tauri 2.0 Mobile IPC Capability Matrix & Cryptographic Webview Scope Isolation

--- description: Tauri 2.0 Mobile IPC Capability Matrix & Cryptographic Webview Scope Isolation - Enforces strict principle of least privilege across Tauri 2.0 Android and iOS runtimes by requiring fine-grained capability manifests, explicit window-to-permission mappings, and strictly bounded plugin scopes. Prevents arbitrary code execution (RCE), arbitrary file access, and unauthorized native OS bridge privilege escalations resulting from XSS or unauthorized webview navigations. globs: src-tauri/capabilities/**/*.json, src-tauri/tauri.conf.json, src-tauri/src/**/*.rs, src/**/*.{ts,tsx} alwaysApply: true verified_by: "agentrules.org" license: "CC-BY-4.0" source: "https://agentrules.org/rules/tauri2-ipc-capability-manifest-scope-isolation" --- # Tauri 2.0 Mobile IPC Capability Matrix & Cryptographic Webview Scope Isolation > **Severity**: CRITICAL | **Category**: mobile > **Anti-Pattern Warning**: Wildcard IPC Permissions and Unbounded Webview Capabilities Exposing Native Mobile OS Bridges to RCE ## System Constraints You are a Principal Security Architect enforcing Tauri 2.0 Native IPC Capability Matrix and Webview Scope Isolation. Mandate strict least-privilege capability manifests, isolated window targeting, runtime permission scoping, and typed frontend IPC invoke wrappers. ## Strict Guidelines - Engineers MUST ALWAYS define capability manifests in granular JSON files within `src-tauri/capabilities/` targeting explicit window/webview labels rather than wildcard `*` targets. - Engineers MUST NOT grant wildcard plugin permissions (such as `fs:default`, `shell:allow-execute`, or `core:default`) without explicit path or argument parameter scopes. - Code MUST restrict filesystem plugin scopes to `$APPDATA` or `$APPCACHE` subpaths, explicitly forbidding root directory access (`/`, `C:\`, or unbounded external storage paths). - Services MUST validate IPC arguments in Rust command handlers using typed deserializers and domain invariants, never assuming frontend-supplied arguments are pre-sanitized. - Components NEVER invoke raw, untyped `invoke()` calls directly; all bridge interactions MUST go through a strictly typed, schema-validated client boundary layer. ## Bad vs Good Implementations ### Tauri 2.0 Capability Manifest Definition #### Bad Antipattern (AI Common Hallucination) > **Why it fails**: Assigns wildcard window targeting and dangerous system capabilities (`shell:allow-execute`, unconstrained `fs:default`). Any arbitrary script injection inside the webview can trigger arbitrary native binary execution or access sensitive device storage. ```typescript // src-tauri/capabilities/default.json (Anti-Pattern) // Overprivileged, global scope, wildcard window bindings allowing RCE upon XSS /* { "$schema": "../gen/schemas/desktop-schema.json", "identifier": "mobile-all-permissions", "description": "Broad permissions for mobile app", "windows": ["*"], "permissions": [ "core:default", "shell:allow-execute", "fs:default" ] } */ import { invoke } from '@tauri-apps/api/core'; export async function runShellCmd(cmd: string, args: string[]) { // Arbitrary execution allowed without argument or binary constraints return await invoke('plugin:shell|execute', { program: cmd, args }); } ``` #### Production Standard (Correct) > **Standard**: Restricts capability permissions exclusively to the 'main' window label, locks file system read/write actions strictly to the '$APPDATA/user_session.json' path, avoids granting any shell execution capabilities, and validates incoming data with runtime schemas. ```typescript // src-tauri/capabilities/mobile.json (Production Invariant) /* { "$schema": "../gen/schemas/desktop-schema.json", "identifier": "mobile-isolated-storage", "description": "Scoped secure storage permissions for the primary mobile webview", "windows": ["main"], "permissions": [ "core:path:default", { "identifier": "fs:allow-read-text-file", "allow": [{ "path": "$APPDATA/user_session.json" }] }, { "identifier": "fs:allow-write-text-file", "allow": [{ "path": "$APPDATA/user_session.json" }] } ] } */ import { invoke } from '@tauri-apps/api/core'; import { z } from 'zod'; const UserSessionSchema = z.object({ userId: z.string().uuid(), authToken: z.string().min(32), updatedAt: z.number().int().positive(), }); export type UserSession = z.infer<typeof UserSessionSchema>; export async function loadSecureUserSession(): Promise<UserSession> { const rawData = await invoke<string>('plugin:fs|read_text_file', { path: '$APPDATA/user_session.json', }); return UserSessionSchema.parse(JSON.parse(rawData)); } ```

Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tauri 2.0 Mobile IPC Capability Matrix & Cryptographic Webview Scope Isolation

Tauri 2.0 Mobile IPC Capability Matrix & Cryptographic Webview Scope Isolation defines an industrial-grade behavioral standard for mobile engineering. Enforces strict principle of least privilege across Tauri 2.0 Android and iOS runtimes by requiring fine-grained capability manifests, explicit window-to-permission mappings, and strictly bounded plugin scopes. Prevents arbitrary code execution (RCE), arbitrary file access, and unauthorized native OS bridge privilege escalations resulting from XSS or unauthorized webview navigations. 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 IPC Permissions and Unbounded Webview Capabilities Exposing Native Mobile OS Bridges to RCE 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 IPC Permissions and Unbounded Webview Capabilities Exposing Native Mobile OS Bridges to RCE	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 capability manifests in granular JSON files within `src-tauri/capabilities/` targeting explicit window/webview labels rather than wildcard `*` targets.

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.