We're excited to announce DevTools, a local-first API testing and flow automation tool. DevTools helps you ship reliable APIs with exportable YAML and a workflow that respects your team's velocity.

Why Local-First?

Your API testing data is sensitive. DevTools keeps everything on your machine:

No cloud dependency: Studio (the desktop app) and the CLI run on your own machine and in your own CI, and need no account
No telemetry: Your data stays private
Git-reviewable: YAML flows are text files you can commit

There is no hosted DevTools. If you want a hosted option, Stresseur Cloud is a separate paid product from the same team that runs DevTools flows in CI.

How It Works

The flow from traffic to tests takes minutes:

Import HAR: Record browser traffic and import the HAR file
Generate Flow: DevTools automatically creates a flow tree with variable mapping
Export YAML: Save flows as reviewable text files
Run in CI: Execute with the Go-based CLI runner

Example Flow

flows:
  - name: AuthFlow
    steps:
      - request:
          name: Login
          method: POST
          url: '{{BASE_URL}}/auth/login'
          body:
            email: "test@example.com"
            password: "secret"
      - request:
          name: GetProfile
          method: GET
          url: '{{BASE_URL}}/me'
          headers:
            authorization: "Bearer {{ Login.response.body.token }}"

Key Features

HAR → Flow Tree: Import browser traffic and get a visual flow graph
Auto Variable Mapping: Tokens/IDs extracted automatically
YAML Export: Flows as text files for PR review
Go-Fast Runner: Parallel execution with multithreaded Go engine
CI Integration: JUnit/JSON reports and deterministic exit codes

What's Next?

We're working on:

AI nodes
Stresseur Studio: in an upcoming release, DevTools Studio becomes Stresseur Studio. It is the same app, still free and open source.

Try DevTools today and see how local-first API testing can transform your workflow.

Download DevTools or Read the Docs