Architecture

Architecture

JobniacFast is a Tauri 2 desktop app and an MCP server over one embedded SQLite file. The Rust core holds all business logic. The React UI only renders and holds UI state.

Layers

flowchart TD
    UI["React UI (src/)"] -->|"invoke, typed bindings"| DESK["jobniac-desktop (src-tauri/)<br/>thin Tauri commands"]
    CLIENT["MCP client"] -->|"stdio or HTTP"| CLI["jobniac-cli<br/>MCP, migrations, maintenance"]
    CLI --> MCP["jobniac-mcp<br/>tool catalog and transports"]
    DESK --> RT["jobniac-runtime<br/>configuration and composition root"]
    DESK --> CORE
    MCP --> CORE
    CLI --> RT
    RT --> CORE["jobniac-core<br/>domain types, use cases, ports"]
    RT --> INFRA["jobniac-infra<br/>SQLite, files, network, workers"]
    INFRA -->|"implements ports"| CORE
    CORE --> TEXT["jobniac-text<br/>Java and Unicode text rules"]
    CORE --> PDF["jobniac-pdf<br/>PDF layout and writing"]
    INFRA -->|"spawns"| WORKER["sandboxed worker processes"]

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Desktop commands and MCP tools sit side by side. Both call the same use cases in jobniac-core. Neither calls the other.

Crates

The Cargo workspace members are under crates/. The desktop crate is in src-tauri/.

Crate	Role
jobniac-core	Framework-free domain types, use cases and ports. No Tauri, database, HTTP or filesystem dependency.
jobniac-infra	Adapters that implement the core ports: SQLite, filesystem, network fetch, and the worker supervisor.
jobniac-runtime	Environment configuration and the composition root, used by the desktop app and the CLI. It takes one snapshot of the process environment and wires core use cases to infra adapters. Opt-in features stay off unless their flag is exactly 1.
jobniac-mcp	MCP tool catalog, tool framework and transports, built on the rmcp SDK.
jobniac-cli	The jobniac-cli console binary: MCP server, migrations, maintenance and the hidden worker modes.
jobniac-pdf	Deterministic Standard-14 PDF layout and writing, plus structural readback checks. No IO.
jobniac-text	Java and Unicode text semantics (UTF-16 lengths, whitespace, case, segmentation), pinned by golden vectors.
jobniac-testkit	Temporary SQLite database helper for tests.
jobniac-desktop (src-tauri/)	The Tauri app. Each #[tauri::command] is a thin adapter over a core use case.

Every command must be registered in tauri::generate_handler![...] in src-tauri/src/lib.rs. The frontend bindings in src/ipc/bindings.ts are generated from the Rust types and CI checks that they are up to date.

UI

The React 19 and TypeScript UI is in src/. It calls Rust through invoke from @tauri-apps/api/core. Rendering, UI-only state and animation live here. Validation of record, persistence and all IO live in Rust.

pnpm dev:mock starts the UI against an in-memory mock IPC (src/dev). The browser UI tests run against it.

IPC rules

• File paths, tokens and secrets never cross IPC.
• i64 values cross IPC as strings.
• MCP tool names, argument keys, envelopes and error semantics are a stable public contract. See Contributing Workflow.

Worker processes

Untrusted input is handled outside the main process. PDF text extraction, PDF page rendering, link fetch and the Arbeitnow board fetch each run in a child process. The child is the hidden mode jobniac-cli __worker <kind>.

• The supervisor in jobniac-infra starts the child with a fixed environment, enforces a deadline, an output cap and cancellation, and kills the process tree.
• The child applies its own limits and sandbox before it reads its request, and refuses to run unconfined.
• Linux: process groups and resource limits, plus no_new_privs, a Landlock ruleset and a seccomp filter. Landlock is used as far as the kernel supports it.
• macOS: process groups, resource limits, a Seatbelt profile per worker kind, and a memory watch by the parent.
• Windows: Job Objects of the parent.

For the source, see crates/infra/src/workers/ in the repository.

See also

• Development Setup
• Testing and CI