1-Click Import From
Postman (v2.0 / v2.1), Bruno, Hoppscotch, Thunder Client, Insomnia (v4 JSON & v5 YAML), OpenAPI / Swagger (JSON or YAML), and raw cURL command GUI import — import curl to api client without scripts.
LOCAL-FIRST REST API CLIENT · COLLECTION RUNNER · SQL WORKBENCH FOR WINDOWS & VS CODE
Test APIs Locally with a Fast, Offline REST API Client & SQL Workbench. No Cloud. No Drama. Install, Import, and Play.
Signoff Studio is a free local-first API testing tool, unlimited collection runner, and SQL database workbench for Windows desktop and VS Code. Test REST, GraphQL, gRPC, WebSocket, SSE, and MQTT without login—your collections stay on your machine as Git-friendly JSON files.
Early Adopter Beta Reward (20 Days Only): Download and install the Windows desktop app during this 20-day beta period and your installation stays 100% FREE FOREVER on that particular machine. Zero charges today, zero charges when beta ends.
Download Free from Microsoft Store
Windows 10/11 App · Lock in Free Forever on your PC
Install Free VS Code Extension
VS Code Marketplace · API, Runner & DB inside VS Code
signoff-studio · local workspace
POSThttps://localhost:8080/v1/orders
pm.test("status is 200", () => {
pm.response.to.have.status(200);
});
200 OK · 38ms
GUI assert · JSONPath $.id
PostgreSQL · orders
[ENV: LOCAL]
SELECT * FROM orders
WHERE id = {{order_id}};
1 row · verified beside API response
Collection Runner · unlimited iterations · 4 parallel workers
128
passed
0
failed
p95 42ms
latency
Reports: JSON · HTML · PDF · JUnit XML · CSV
Engines: PostgreSQL · MySQL · SQL Server · Oracle · SQLite
Read-Only flag
Typed confirm on Production
Schema browser
-- Safety rails before destructive SQL -- Connection badge: Staging | Production
my-api-workspace/ ├── signoff-workspace.json ├── collections/ # Sorted, human-readable JSON ├── environments/ ├── runner/plans/ & schedules.json ├── database/ └── .gitignore # Vault & secrets protected
Import Postman, Bruno, Insomnia, OpenAPI & cURL in Seconds
Switch in 60 seconds. Zero lock-in. Your offline api client and local first api client workflow starts with files you already own.
OpenAPI Spec Viewer & Tester
Link an OpenAPI 3.0 spec and click Sync from OpenAPI (match by operationId or method + path). Keep or delete orphans. A full openapi client desktop with openapi spec viewer and tester — import openapi spec to test api in one flow.
Never Locked In
Export anytime to Signoff JSON, Postman Collection v2.1, Bruno folder/ZIP, or OpenAPI 3.0. A true postman alternative offline and bruno alternative with sql workbench—not a proprietary trap.
Drop-In Script Compatibility
Native pm.*, bru.*, pw.*, and qa.*. Pre-request and post-response scripts run without rewriting a single line.
Six Core Product Pillars
A desktop api client and http client gui download that covers protocols, auth, asserts, runner, SQL, and AI agents—without cloud drama.
1. Six-Protocol Desktop API Client & Stream Timeline
Protocols: REST/HTTP, GraphQL, WebSocket, SSE, gRPC, and MQTT in one unified GUI. REST methods GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS with query params, headers, cookies, and {{variable}} substitution across URLs, headers, params, and bodies (JSON, form, multipart, GraphQL, binary, XML, text, HTML, SOAP, JavaScript). gRPC GUI client download: Unary plus Server, Client, and Bidirectional streaming with Discover via Server Reflection. GraphQL IDE offline / graphql client desktop download: schema introspection, docs panel, autocomplete, HTTP queries/mutations, subscriptions over graphql-ws. MQTT client tester over mqtt:// and mqtts://. WebSocket testing tool desktop and SSE client tester share a unified stream timeline. Generate snippets in 21 languages: Shell (cURL, HTTPie, Wget), C, Clojure, Crystal, C#, Go, HTTP, Java, JavaScript, Kotlin, Node.js, Objective-C, OCaml, PHP, PowerShell, Python, R, Ruby, Rust, Swift.
2. Auth & Encrypted Local Vault
No Auth, Inherit, Bearer, Basic, API Key, OAuth 2.0, OAuth 1.0, Digest, AWS Signature v4, Hawk, Custom Headers. OAuth 2.0: Authorization Code + PKCE, Client Credentials, Refresh Token—refresh tokens auto-retry once on expiry or HTTP 401. Host-level AWS and Hawk signing after env resolve. Encrypted credential vault stays on your machine—api client no account required for secrets.
3. Dual Testing Engine
Scriptless GUI asserts on status, latency, headers, body, JSONPath—plus live stream asserts for WebSocket, SSE, and gRPC. Sandboxed JS with pm.* / qa.* and bru.* / pw.* aliases. Honor pm.execution.setNextRequest and skipRequest. Helpers: pm.sendRequest, cookies jar, visualizer, crypto, JSONPath, retries.
4. Unlimited Runner, Load & CI CLI
Api client no collection runner limit: entire collection, folder, or cherry-picked requests with unlimited iterations, parallel workers, CSV/JSON datasets. Reports: JSON, HTML, PDF, JUnit XML, CSV. In-app scheduled monitors while the Windows app or VS Code Runner panel is open (runner/schedules.json). Local load testing up to 200 VUs with p95 / error-rate gates. CLI api testing tool via npm run runner for GitHub Actions, GitLab CI, Jenkins—exit code 1 on failure.
5. SQL Database Workbench
Query PostgreSQL, MySQL, SQL Server, Oracle, and SQLite beside your API requests. Syntax-highlighted editor, schema browser, connection test, auto-reconnect, CSV export. Environment badges (Local, Dev, Staging, Production), Read-Only flag, and typed confirmation before risky production SQL—the missing link Postman, Bruno, and Insomnia never shipped.
6. Local Mock Server & AI-Ready MCP
Instant local mock on 127.0.0.1 or npm run mock—Saved Response Examples → OpenAPI Examples → Schema Stubs. Built-in MCP server (npm run mcp) for Cursor & VS Code AI agents: list collections, inspect environments, fetch schemas, execute requests (capped at 50 unless confirmed) with automatic secret redaction.
Store API Collections in Git with Clean, Deterministic Pull Request Diffs
- Zero “Save” button anxiety. Create, open, or duplicate workspaces—every edit writes to disk automatically.
- Deterministic PR diffs. JSON keys sorted on write. Enforce in CI with npm run workspace:normalize.
- Secret hygiene. Built-in .gitignore and .env.example keep vault secrets out of Git history.
- A git friendly api client and git native api client that is also a file based api client—store api collections in git without cloud blobs.
my-api-workspace/ ├── signoff-workspace.json ├── collections/ # Sorted, human-readable JSON requests ├── environments/ # Shared env vars (.env.example safe) ├── runner/ │ ├── plans/ # Saved test suites & load profiles │ └── schedules.json # Local monitor definitions ├── database/ # Saved SQL queries & connection configs └── .gitignore # Protects local vault & secrets
Why Developers Switch: Signoff Studio vs. Postman, Bruno & Insomnia
An insomnia alternative no login, a lightweight api client, and a fast rest api client—without collection runner paywalls.
| Capability | Signoff Studio | Postman | Bruno | Insomnia |
|---|---|---|---|---|
| Mandatory Cloud Login / Account | Never — 100% Offline API Client | Forced Cloud Sync | No | Account Required for Sync |
| Pricing / Early Adopter Offer | FREE FOREVER on your machine during 20-Day Beta | $14–$49/user/mo | $19–$39/user/mo Pro/Golden | $12–$45/user/mo |
| Storage Format on Disk | Deterministic Sorted JSON | Cloud Database Blob | Custom .bru DSL | Local DB / Cloud |
| Native Script Compatibility | pm.*, bru.*, pw.*, qa.* | pm.* only | Requires bru.* or translation | insomnia.* |
| Scriptless Point-and-Click Assertions | Yes — REST + WebSocket/SSE/gRPC Streams | No | Basic Asserts | No |
| Local Collection Runner Limits | Unlimited + Parallel + PDF/JUnit | Capped at 25 runs/mo Free/Basic | Unlimited (PDF/JUnit paid) | Limited |
| Integrated SQL Database Workbench | Postgres, MySQL, SQL Server, Oracle, SQLite | None | None | None |
| Built-in Local Load Testing (Up to 200 VUs) | Included Free | Limited / Cloud constraints | No | No |
| Local MCP Server for Cursor / AI Agents | Built-in (npm run mcp) + Secret Redaction | No / External plugins | No / External plugins | No / External plugins |
20-Day Beta Launch: Install Today, Keep It Free Forever on Your Machine.
We are running a 20-day public beta to reward early adopters. Install Signoff Studio on your Windows machine during these 20 days and we will never charge you on that machine—it stays unlocked and free forever on that particular workstation. No credit card, no account registration, no trial expiration. Best free api testing tool timing: claim your free rest client for windows before 2026-11-03T23:59:59Z.
api testing tool free download → Microsoft StoreWindows Desktop App
Microsoft Store: API + Runner + DB + Built-in Git Workbench (clone, branch, checkout, commit) + Monitors + PDF Reports + in-app updates via GitHub Releases. Free Forever on your machine when installed during the 20-day Beta. Rest api client download / desktop api client / local api tester.
Get on Microsoft Store →VS Code Extension
Marketplace: API + Runner + DB inside VS Code. Test API inside VS Code while Git stays in Source Control. 100% Free vscode rest client extension.
Install from Marketplace →Headless CLI
npm run runner / mock / mcp: collection runs, local load testing, 127.0.0.1 mock server, MCP for Cursor/VS Code, JUnit/PDF CI reports. Api request builder download for pipelines.
What We Don’t Do
No Hidden Background Daemons
Scheduled monitors run while the Windows app or VS Code Runner panel is open—schedules do not keep firing after the app closes.
Focused Local Load Testing
Process-local virtual users (up to 200 VUs) are built for fast local endpoint verification, not distributed cloud load or k6 import.
Pure Relational SQL Focus
Supports PostgreSQL, MySQL, SQL Server, Oracle, and SQLite. MongoDB, Redis, and non-SQL engines are not supported.
FAQ
Install the Windows desktop app during the public beta ending 2026-11-03T23:59:59Z. That installation stays unlocked and free forever on that particular machine—no credit card, no cloud login. The VS Code extension stays free on the Marketplace regardless.
Signoff Studio is an offline api client / offline rest client and api testing tool without login. Test api locally with a local rest api client—collections stay on disk. No mandatory cloud account.
Import Postman, Bruno, Hoppscotch, Thunder Client, Insomnia, OpenAPI, or cURL. Existing pm.*, bru.*, pw.*, and qa.* scripts run without rewriting.
Deterministic sorted JSON for clean PR diffs, plus SQL verification beside API asserts—so “200 OK” and the database row tell the same story.
Install the free Marketplace extension to test api inside vscode. Run npm run mcp for Cursor / VS Code agents with secret redaction.
Supported Workflows & Capabilities
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