Volley documentation
Everything Volley does and how to use it, from your first arrow to drift checks in CI.
Getting started
What Volley is, and a first diagram in a few minutes.
Writing diagrams
The plain-text syntax, from arrows to payloads.
Using the editor
Write, read, present and share diagrams.
Capturing traffic
Build and check diagrams from real requests.
Your account
Save, organise and pay for Volley.
Agents and API
Let AI agents and scripts read and write diagrams.
Help
When something does not look right.
What Volley is
Volley is a tool for sequence diagrams of API flows. You write the flow as plain text, one arrow per line, and Volley draws it. What sets it apart is that every arrow can carry its request and its response: the JSON body, the form fields, the headers, the status code. The diagram stays clean, and one click on an arrow shows exactly what was sent and what came back.
You can also build diagrams from real traffic instead of writing them: import a browser recording, catch webhooks in an inbox, or ask a customer to record their problem. Once a diagram exists, Volley can check it against a fresh recording and tell you which steps no longer match the API.
People write Volley diagrams, and so do AI agents. The syntax is short and forgiving, errors come with a line and column, and agents can reach Volley through an MCP server, an HTTP API, a command line tool and tools inside the editor page.
Where to start
- New to Volley? Follow the Quickstart. It takes about five minutes.
- Looking up a statement? The Syntax reference has all of them on one page.
- Documenting an existing API? Import a HAR file and tidy the result.
- Keeping docs honest? Read Update from a recording.
- Connecting an agent? Start with the Agents overview.
Finding your way around these docs
- Press / or Ctrl+K on any docs page to search. Use ↑ and ↓ to pick a result and Enter to open it.
- Press [ and ] to go to the previous and next page, in the order of the menu.
- Press ? to see every docs shortcut.
- Without a keyboard, use the search box and the menu on the left, the "On this page" list, and the Previous and Next links at the bottom of each page.
Free and Pro
The editor is free and needs no account. Signing in, which is also free, adds a saved diagram with a short link and the capture tools. Pro adds more of everything plus collections, version history, private diagrams, presentations and the agent skill. Pages that describe a Pro feature say so at the top. See Plans and billing for the full comparison.