Flows
Testing a real API journey almost never means firing one request. It means: log in, take the token from the response, use it on the next call, check that call returned what you expected, maybe loop over a list, maybe branch on a status code. Doing that by hand in Composer means re-typing headers and copy-pasting values between tabs, every single time you want to re-run it.
Flows turn that journey into a diagram you build once and run forever. Drag requests onto a canvas, wire them together, tell Probe which values to carry from one response into the next request, and add assertions to check what came back. Hit Run and watch each node light up as it executes. Save the flow, share it with a teammate as a file, or run it headlessly in CI.
What a flow is
Section titled “What a flow is”A flow is a small graph:
- Nodes are steps — an HTTP request, a branch, a loop, a pause, a call into another flow, or a script.
- Edges are the order nodes run in. Drag from one node's out-port to another node's in-port to connect them.
- Variables carry data along the edges. Name an extraction on a request node (e.g. pull
tokenout of the login response body), and any downstream node can reference it as{{login.outputs.token}}— in a URL, a header, or a body field.
That's the whole model. There's no separate "test script" language to learn for the common case — extractions and assertions are just fields you fill in on a node, and they show up right there on the canvas.
Where it lives
Section titled “Where it lives”Flows share the request-building side of Probe with Composer. Click the Proxy / Compose toggle in the toolbar to switch into Composer view, then look for the FLOWS section in the sidebar, below your collections. Click + to create a new flow, or click an existing one to open (or refocus) its tab.
Because a flow's request nodes reference real requests from your Composer collections, every flow node has access to the same headers, body types, and auth config you already set up there.
Layout
Section titled “Layout”┌───────────────────────────────────────────────────────────┐│ Run ▶ Stop ■ Environment: Dev ✓ 3 passed ✗ 0 failed │ ← run toolbar├───────────────────────────────────────────────────────────┤│ ││ ┌────────┐ ┌────────────┐ ┌───────────────┐ ││ │ Start │─────▶│ Login │─────▶│ Get Profile │ │ ← canvas│ └────────┘ │ (request) │ │ (request) │ ││ └────────────┘ └───────────────┘ ││ │├───────────────────────────────────────────────────────────┤│ Run Report ││ ✓ Login 200 OK 142ms 1 output │ ← report panel│ ✓ Get Profile 200 OK 98ms 2/2 assertions │└───────────────────────────────────────────────────────────┘Requests get dragged onto the canvas straight from the Composer collection tree in the sidebar. Selecting a node opens its inspector (config: extractions, assertions, condition expression, loop source, etc.) — the inspector panel isn't drawn above because it docks to whichever side has room, but it's always one click away.
The seven node types
Section titled “The seven node types”Every flow is built from seven kinds of node — Start, Request, Condition, Loop, Delay, Sub-flow, and Script. See Node Types for what each one does, its ports, and its settings.