Test APIs Locally with a Fast, Offline REST API Client & SQL Workbench. No Cloud. No Drama. Install, Import & Play.
Signoff Studio is a local-first API testing tool, unlimited collection runner, and relational SQL workbench for Windows and VS Code. Send REST, GraphQL, gRPC, WebSocket, SSE, and MQTT without mandatory logins—your workspaces stay on your disk as deterministic, Git-ready JSON files.
Install the Windows desktop app during our 20-Day Public Beta and your workstation license stays 100% Free Forever on that particular machine. No subscription, no telemetry, no trial bomb.
pm.test("Order created & ID returned", () => {
pm.response.to.have.status(200);
bru.setEnvVar("order_id", pm.response.json().id);
});{ "id": "ord_99481a", "status": "PAID", "amount_cents": 49900 }SELECT id, status, amount_cents, created_at
FROM public.orders
WHERE id = '{{order_id}}';| id | status | amount_cents |
|---|---|---|
| ord_99481a | PAID | 49900 |
PRODUCTION enforce Read-Only mode or require typed confirmation before DROP / DELETE / UPDATE.
my-api-workspace/
├── signoff-workspace.json
├── collections/ # Sorted keys for clean PR diffs
├── environments/ # Shared env vars (.env.example)
├── runner/
│ ├── plans/ # Saved test suites & load profiles
│ └── schedules.json # In-app monitor schedules
├── database/ # Saved SQL queries & schemas
└── .gitignore # Keeps vault secrets out of Git
Run npm run mcp to let Cursor or VS Code AI agents list collections, inspect environments, read request schemas, and run collections (capped at 50 requests unless confirmed) with automatic secret redaction.
Bring Your Existing Collections. Run pm.* and bru.* Scripts Out of the Box.
No lock-in and no rewriting tests into a custom DSL. Import in one click, link an OpenAPI 3.0 spec for 2-way sync, and export back to Postman, Bruno, or OpenAPI anytime.
Six Integrated Tools in One Local-First Binary.
Every feature is engineered to run directly on your machine—combining a multi-protocol API client, scriptless and JS testing engine, collection runner, SQL database workbench, local mock server, and AI MCP bridge.
Six-Protocol Desktop API Client & Unified Stream Timeline
Send REST (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS), GraphQL (schema introspection, docs panel, field autocomplete, graphql-ws subscriptions), gRPC (unary, server, client & bidirectional streaming with Discover via Server Reflection), WebSocket, SSE, and MQTT (mqtt:// & mqtts:// with topic, QoS & publish).
Complete Auth & Encrypted Local Vault
Supports Bearer, Basic, API Key, OAuth 2.0 (Auth Code + PKCE, Client Credentials, Refresh Token with automatic retry on expiry or HTTP 401), OAuth 1.0, Digest, AWS Signature v4, and Hawk signed on the host after variables resolve.
Scriptless GUI Asserts + Sandboxed JS
Build point-and-click assertions on status, latency, headers, body, and JSONPath—plus live stream asserts for WebSocket, SSE, and gRPC. Or write full JS tests with pm.*, qa.*, bru.*, and pw.*.
Unlimited Runner, Local Load & CI CLI
Run collections or folders with parallel workers and CSV/JSON datasets. Export JSON, HTML, PDF, JUnit, and CSV reports. Run local load tests (up to 200 virtual users with p95/error thresholds) and in-app scheduled monitors.
Integrated SQL Database Workbench
Query PostgreSQL, MySQL, SQL Server, Oracle, and SQLite right beside your API response. Includes schema browser, syntax-highlighted SQL editor, CSV export, read-only flags, and typed confirmation before risky production SQL.
Built for Git Pull Requests & AI Editors (Cursor / VS Code)
Every workspace change writes automatically to disk with deterministic sorted JSON keys so pull-request diffs stay clean (npm run workspace:normalize). Spin up a local mock server on 127.0.0.1 (npm run mock) or expose your collections to Cursor and VS Code AI agents via npm run mcp with automatic secret redaction.
Why Teams Switch from Postman, Bruno & Insomnia
Compare local storage, script compatibility, collection runner limits, and built-in database tooling side by side.
| Capability | Signoff Studio | Postman | Bruno | Insomnia |
|---|---|---|---|---|
| Mandatory Cloud Login | ✓ Never — 100% Offline Local-First | ✕ Cloud account pushed for features | ✓ Offline | Account required for full sync |
| Early Adopter License | 🎁 Free Forever on Machine (20-Day Beta) | $14 – $49 / user / mo | $19 – $39 / mo for Pro tiers | $12 – $45 / user / mo |
| Native Script Compatibility | ✓ Runs pm.*, bru.*, pw.* & qa.* natively | pm.* only | bru.* (requires migration) | insomnia.* |
| Scriptless Point-and-Click Asserts | ✓ REST + WebSocket, SSE & gRPC Streams | ✕ JavaScript required | Basic HTTP asserts | ✕ No |
| Local Collection Runner Limits | ✓ Unlimited + Parallel + PDF/JUnit Reports | ✕ Capped at 25 runs/mo on Free/Basic | Unlimited (PDF/JUnit in paid tier) | Basic runner |
| Built-In SQL Database Workbench | ✓ Postgres, MySQL, SQL Server, Oracle, SQLite | ✕ None | ✕ None | ✕ None |
| Local Load Testing (Up to 200 VUs) | ✓ Built-in with p95 & error-rate gates | Limited | ✕ None | ✕ None |
| Local MCP Server for Cursor / VS Code | ✓ Built-in (npm run mcp) + Secret Redaction | External / Cloud | ✕ None | ✕ None |
Install During Our 20-Day Beta. Keep It Free Forever on Your Machine.
We are rewarding early adopters with a permanent workstation unlock. Download and install the Signoff Studio Windows app before November 3, 2026, and we will never charge you on that machine—all four modes (API, Runner, DB, and Git) stay unlocked forever.
Windows Desktop App
Four full modes: API, Runner, DB, and Git Workbench (clone, branch, checkout, commit). Includes in-app scheduled monitors, native PDF report generation, and automatic updates via GitHub Releases.
Install from Microsoft Store →VS Code Extension (100% Free)
Brings API, Runner, and DB modes directly inside Visual Studio Code while Git stays natively in VS Code Source Control. Shares the exact same on-disk workspace and cookie jar as the Windows app.
Install from VS Code Marketplace →Headless CLI & MCP Server
Run collections in CI (npm run runner), spin up local mock servers (npm run mock), and connect Cursor or VS Code AI agents (npm run mcp) with JUnit/HTML/JSON reporting.
Radical Engineering Transparency: What Signoff Studio Does Not Do
Frequently Asked Questions
How does the 20-Day Beta "Free Forever on your machine" offer work? +
Anyone who downloads and installs the Signoff Studio Windows desktop application during our 20-day public beta window (ending November 3, 2026) locks in a permanent free license on that workstation. You will never be charged on that machine, and no credit card or account login is required.
Can I import my existing Postman (pm.*) and Bruno (bru.*) collections without rewriting scripts? +
Yes. Signoff Studio imports Postman v2.0/v2.1, Bruno, Insomnia v4/v5, Hoppscotch, Thunder Client, OpenAPI 3.0, and cURL commands, and natively supports pm.*, bru.*, pw.*, and qa.* script aliases in its JavaScript sandbox.
How does Signoff Studio keep Git pull requests clean? +
Workspaces are plain files on disk with deterministic, alphabetically sorted JSON keys and automatic .gitignore / .env.example generation so secrets stay in your local encrypted vault while diffs stay human-readable.
Why use a Git-friendly file-based REST API client with a built-in SQL workbench? +
Testing an API rarely stops at 200 OK. Signoff Studio pairs a git-native, file-based API client with PostgreSQL, MySQL, SQL Server, Oracle, and SQLite so you can verify the database row changed beside your request.
How do I test APIs inside VS Code or connect collections to Cursor via MCP? +
Install the free VS Code Marketplace extension to test APIs inside VS Code. Run npm run mcp to connect Cursor or VS Code AI agents to your workspace with automatic secret redaction.