Recording a session (loadr record)

You don't have to hand-write a test, and you don't have to export a HAR from devtools either. loadr record starts a capturing proxy: point a browser, an app, or curl at it, do the journey you want to load-test, and on Ctrl-C it emits a ready-to-run scenario — with dynamic values (tokens, CSRF, ids) auto-correlated by the same engine behind loadr convert har.

Quick start

$ loadr record -o checkout.yaml
loadr record  recording proxy on 127.0.0.1:8888
  Point your client at it, e.g.:
    export HTTP_PROXY=http://127.0.0.1:8888 HTTPS_PROXY=http://127.0.0.1:8888
  Ctrl-C to stop and emit the scenario.

In another terminal, drive your journey through the proxy:

$ curl -x http://127.0.0.1:8888 -X POST https://api.example.com/login -d '{"user":"alice"}'
$ curl -x http://127.0.0.1:8888 https://api.example.com/profile

Back in the first terminal, press Ctrl-C. loadr writes checkout.yaml and tells you what it correlated:

record: stopping — 2 transaction(s) captured
note: [request #1] auto-correlated `token` ($.token from the response) into 1 later request(s) — review it
record: wrote checkout.yaml

Recording HTTPS

The proxy terminates TLS so it can see the plaintext (a man-in-the-middle on your own traffic, on localhost). Trust its CA once:

$ loadr record --trust
loadr record CA certificate:
  ~/.config/loadr/record-ca-cert.pem
  ...per-OS install instructions...

The CA is generated on first use and stored under ~/.config/loadr ($XDG_CONFIG_HOME/loadr). A fresh leaf certificate is minted per host on demand and cached for the session. Remove the CA from your trust store when you're done if you prefer — a new one is minted on demand next time.

What you get

The emitted plan is a normal loadr scenario, so you can run it immediately and then shape it into a real load test:

scenarios:
  recorded:
    executor: constant-vus      # a safe default — set real load next
    vus: 1
    duration: 1m
    flow:
    - request:
        name: POST /login
        method: POST
        url: /login
        body: '{"user":"alice"}'
        extract:
        - type: jsonpath
          name: token
          expression: $.token        # ← auto-correlated
    - request:
        name: GET /profile
        method: GET
        url: /profile
        headers:
          authorization: Bearer ${token}   # ← substituted

Static assets (images, CSS, fonts) are dropped automatically so the scenario stays focused on the API calls that matter.

Options

Next steps

• Set a real executor, vus/rate and duration (see Scenarios & executors).
• Review the correlations — the heuristic is good but not infallible.
• Add thresholds so the run has a pass/fail gate.