Native for macOS · no Electron · no accountNative macOS · no Electron

The REST client that feels like a Mac app.

SwiftUI and SwiftData, top to bottom. Launches in under a second, keeps your requests on your Mac, and never asks you to sign in.

POSTCreate manifest✕

POST{{BASE_URL}}{{MANIFESTS_PATH}}/manifests⋯Send⌘↵

https://api.acme-labs.dev/launch/v1/manifests

ParamsHeaders2BodyAuthVariablesPost-Response1

KeyValueDescriptionBulk edit

Content-Typeapplication/json

AuthorizationBearer {{SESSION_TOKEN}}Captured from auth-service

KeyValueDescription

201CreatedTotal218 msSize1.4 KBHTTP1.1 ⌄⋯

POSThttps://api.acme-labs.dev/launch/v1/manifests

BodyHeaders6CookiesTimingsCaptures1

PrettyRawTreePreview⌄ JSON{}

{
  "id" : "mf_7f3a9c",
  "status" : "scheduled",
  "vehicle" : "Kestrel-2",
  "window" : "2026-09-14T06:40:00Z",
  "crew" : { "team" : "ops-night", "seats" : 4 }
}

Connected·HTTP/1.1·TLS 1.3·IdleUTF-8·1.4 KB·Live·⌘KCommand palette

Goes with the system

Command palette on ⌘K, Spotlight indexing, Shortcuts actions, real menu bar, real sheets.

Your data stays home

SwiftData on disk. iCloud sync is opt-in and end-to-end Apple's. We run no servers of our own.

Try all of it first

Every feature free for a month, with no account. Then $29.99 a year — or $79.99 once, yours to keep.

Environments

Switch environment, not fifteen URLs.

Pick the environment in the toolbar; every {{variable}} in the request resolves live, highlighted in violet, with the final URL rendered right under the field. Edit the whole set in a sheet without leaving the request.

Environments

StagingActive

Default

Local

Production

+New environment

BASE_URLhttps://api.acme-labs.dev

MANIFESTS_PATH/launch/v1

MISSION_IDmsn_4k9q2z

SESSION_TOKEN••••••••

REGIONeu-west-1

+New variable

KeyBASE_URLValuehttps://api.acme-labs.devEnabledSecretDelete variable

Done

Response viewer

See where the 218 ms went.

Every response comes back with a waterfall — DNS, TCP, TLS, request, waiting, download — next to a JSON viewer that folds, filters and searches without freezing on a 2 MB body.

200OKTotal218 msSize1.4 KBHTTP1.1 ⌄⋯

GEThttps://api.acme-labs.dev/launch/v1/manifests/mf_7f3a9c

BodyHeaders6CookiesTimingsCaptures1

Request timing

Prepare4 ms

DNS lookup14 ms

TCP connect22 ms

TLS handshake39 ms

Request sent1 ms

Waiting (TTFB)103 ms

Download32 ms

Process3 ms

Total elapsed218 ms

Command palette

Everything is one `⌘K` away.

Create, navigate, execute, or jump back through history — grouped, fuzzy-matched, keyboard-first. The palette is the fastest way to send a request you haven't opened yet.

Search commands…Smart6 results

Create

New Requestlaunch-manifests⌘T

New Collection⌘⌥N

Navigate

Show History⌘⇧H

Toggle Sidebar

Execute

Send RequestCreate manifest⌘↩

Run Collection · launch-manifests⌘R

↩Select↑↓Navigate⌘KCloseMariner · Command palette

Migrate & automate

Bring what you have. Run it all at once.

Import from Postman, OpenAPI or a pasted cURL, and export back out as code in five languages. The collection runner adds per-step assertions and a report you can hand to someone else.

Import

Postman collections v2.1
OpenAPI 3.x
Paste a cURL command

Generate

cURL
Swift
Python
JavaScript
Go

Runnerlaunch-manifests · 6 steps6 passed

GETInfostatus = 200 · 218 ms

POSTCreate manifestbody.id exists · 340 ms

PATCHUpdate manifeststatus = 204 · 96 ms

Advanced · MCP server

Your agent can send the request too.

Mariner ships an embedded MCP server. Point Claude Code — or any MCP client — at it, and it can read your collections, resolve environments and execute requests, with the same local data and no API keys leaving your Mac.

Off by default. One toggle, scoped per workspace.

Terminal

$ claude mcp add mariner \
  --transport stdio \
  -- /Applications/Mariner.app/Contents/MacOS/mariner-mcp-- mariner-mcp

Added MCP server mariner. Tools:
list_collections, get_request, run_request, list_envs

iCloud syncOpt-in, per workspaceOpt-in
WorkspacesSeparate clients, separate envsSeparate envs
Local historyEvery send, searchable
AuthOAuth2, Bearer, API key, BasicOAuth2 · Bearer · Basic
Languagesen · es · pt-BR
SwiftUI nativeNo web view anywhere
Apple SiliconUniversal, macOS 15+macOS 15+
Post-response captureTokens straight into variables

Pricing

A month on us. Then pick how you pay.

Every feature, free for a month — confirmed in the App Store, and nothing is charged if you cancel before it ends. After that it is one price for everything: by the year, or once.

Yearly1 MONTH FREE

29.99USD · a year

Starts with a free month. Cancel before it ends and you pay nothing.

The toolbar shows the day the free month ends
Cancel any time from the App Store
Family Sharing: one subscription, your whole family

Lifetime

79.99USD · once

Pay once, keep it. No renewal, nothing to cancel.

For people who would rather not rent a developer tool
Family Sharing included
Restores on every Mac with your Apple Account

Both plans include everything

Unlimited requests, collections, workspaces and environments
Every body editor, body variants and the response viewer
Basic, Bearer, API key and both OAuth 2 flows
Postman, Insomnia, OpenAPI and cURL import
Request chaining, contracts and the collection runner
Swift, Go, Python and JavaScript snippets, types and HTML docs
iCloud sync across your Macs
The MCP server, so an agent can send the request too

How the free month works →

The name · NASA, 1962–1973

Named after the probes that went first.

Mariner 4 reached Mars in July 1965 and radioed back twenty-one grainy frames at 8⅓ bits per second — humanity's first close look at another world.

That is the idea behind the app. Every request is a small probe: it leaves your Mac, reaches an endpoint, collects what it finds and comes home. No mission control in the cloud.

1962 · Mariner 2first successful flyby of another planet — Venus
1965 · Mariner 421 frames from Mars · 8⅓ bps
1971 · Mariner 9first spacecraft to orbit another planet
1974 · Mariner 10Mercury, on the first gravity-assist trajectory
— end of transmission · 8⅓ bps —