the messenger of your APIs
Simple ➫ No Account. No Cloud. Free.
Free · No account required · Windows coming soon
HTTP & HTTPS only — gRPC, GraphQL, and WebSockets are not supported
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Why this exists
Postman wants a subscription. Insomnia wants your account. Your credentials end up in someone else's cloud. You just want to hit an API — without the song and dance.
This is rough around the edges. That's kind of the point — you're here to break it before anyone else does.
What's different
API keys and secrets live in files on your machine, never in a vendor's cloud. Never in a browser tab, never in a network request, never in a log.
Download and run. No sign-up, no email, no OAuth flow with a third party. Your tool, your machine, your data.
Your workspace is just a folder. Sync it with Git, iCloud, OneDrive, Google Drive, Dropbox — whatever you already use. No sync subscription, no lock-in.
Small binary, fast startup, no bundled browser engine weighing it down.
Full Moon, Dark Moon, Sunlight — switch in one click from the titlebar. Every surface adapts instantly.
Direct Mode
Browser-based API clients can't make arbitrary HTTP requests — CORS stops them. So they ship a background agent you have to keep running just to use the tool.
kbootar makes requests directly from the native app. Nothing extra to install. Nothing to restart when it crashes.
Other tools
Agent must be running. Must be updated. Must not crash.
kbootar
That's it. Open the app, send the request.
Bypass Mode
Switch to Bypass and point kbootar at any intermediate server — Node.js, Spring Boot, anything you're already running. Your server sits between kbootar and the target API. It can add auth headers, transform the request, enforce policies, or reach APIs on a private network. No constraints on what that server does or how it's built.
Bypass routing modes
Direct to the target. Through a server you control. Shared across your whole team — kbootar adapts to how you work.
The app makes requests directly from your machine — no middleman, no setup. Works for any API your machine can reach: public endpoints, localhost, or internal services on the same network.
Point kbootar at a self-managed kbootar bypass server — running on your LAN, inside a VPC, or on any machine your laptop can't reach directly. The server proxies the call to the target API, attaches auth headers, enforces mTLS, and applies your policies. Credentials never leave the server.
When a team runs a shared self-managed kbootar bypass server, every developer routes through it regardless of which API they're hitting. Different teams can run their own dedicated servers, share a common one, or both — with cross-connections handled automatically. No VPN config shared around, no credential spreadsheets.
Collections
Nested folders, per-request method colours, drag-and-drop that works in a real native window. Save any tab to a collection in one click.
TLS & Certificates
Every request goes through a native HTTP engine, not a browser sandbox. mTLS, custom cipher suites, per-request TLS version control — things a web app simply cannot do.
Scripting
Every request can carry two JavaScript hooks. Prepare runs before the request leaves — set headers, tweak the URL, mint a nonce. Eval runs on the response — assert on it, extract values, feed the next request.
{{access_token}}kb.expect with toBe, toContain, toMatch & morekb.setHeader('X-Request-Time', String(Date.now()));
kb.setQuery('source', 'kbootar');
kb.setEnv('nonce', String(Date.now()));const res = kb.response.json();
kb.test('login succeeds', () => {
kb.expect(kb.response.status).toBe(200);
kb.expect(res.access_token).toBeDefined();
});
kb.setEnv('access_token', res.access_token);
Environments
Every {{variable}} in your URL, headers, body, and auth tokens resolves the moment you switch environments. One click moves you from dev to staging to prod — no copy-pasting, no manual edits.
Themes
Full Moon, Dark Moon, Sunlight — switch between them in one click from the titlebar. Syntax highlighting, panels, and every surface adapt instantly.
Workspace
Everything lives in ~/.kbootar/ — plain files you can inspect, back up, or version-control. No accounts, no sync servers, no lock-in. Multiple workspaces for different projects.
Free · No account required · Beta of beta
Sharing this link? Please don't — this is just for you. The wider beta will have its own moment.
macOS
12.0 Monterey or later
Windows
Windows 10 or later
Coming soon