Comments
>log in to commentHi DevHunt! I've found that a good sequence diagram can solve almost any communication problem in engineering, but the ones I kept drawing for API work stopped at "App calls Auth Server" and left the reader digging through docs. Volley puts the real request and response on every arrow. You can write flows in plain text, or build them from webhook inboxes, HAR files and customer recording links (secrets stripped in the browser). It's also easy for AI tools to write, with an MCP server, CLI and HTTP API. The editor is free with no account. I'd love feedback on the syntax and on what you'd want to capture next.
Volley creates live API sequence diagrams that show request and response payloads on each arrow.
- for
- Developers and teams documenting API integrations and debugging webhooks.
- pricing
- freemium
Key features
- Plain-text editor — Write flows in plain text and see the diagram update instantly.
- Real traffic capture — Import HAR files, webhook inboxes, or recording links to build diagrams from actual requests.
- AI integration — ChatGPT, Claude or Gemini can generate diagrams via a simple prompt.
- CLI & HTTP API — Check, render, verify and save diagrams programmatically for CI/CD.
- Sharing & embeds — Shareable links, SVG/PNG export and README embeds that stay up-to-date.
- Version history — Pro users get up to 50 versions per diagram with visual diff.
Use cases
- Document OAuth flows with exact request/response details
- Debug webhook integrations by capturing live events
- Generate API docs that stay in sync via HAR recordings
- Provide customers a link to record their flow and receive a diagram
- Embed living sequence diagrams in READMEs for onboarding
Volley pricing
- Free$0Unlimited local diagrams · 3 saved cloud diagrams · 1 webhook inbox (25 req/mo) · 1 recording link (3 recordings)
- Pro$9 / month/monthUp to 1,000 saved diagrams · 20 webhook inboxes (5,000 req/mo) · Version history · Presentation mode
Volley vs alternatives
 Volley |  Postman |  Insomnia |  Bruno |  Postmark | |
|---|---|---|---|---|---|
| Best for | Live sequence diagrams with real traffic | API testing and docs | REST/GraphQL client | Git-friendly API client | Email delivery |
| Pricing | Freemium | Subscription | Free | Free | Subscription |
| DevHunt upvotes | 1 | 0 | 0 | 0 | 0 |
| Launched | Oct 2026 | — | — | — | — |
- Volley vs Postman: Postman focuses on API testing and documentation, not live sequence diagrams with payloads on arrows.
- Volley vs Insomnia: Insomnia is an API client for testing, lacking automated diagram generation from traffic.
- Volley vs Bruno: Bruno offers offline API client features but does not visualize request/response flows as diagrams.
- Volley vs Postmark: Postmark handles transactional email delivery, unrelated to API flow diagramming.
Volley FAQ
Is Volley free and do I need an account?+
The editor is free and works without an account; sign-in only for saved diagrams, webhook inboxes or Pro features.
Can I create a diagram from a HAR file?+
Yes—drop the HAR into the editor; it parses requests, redacts secrets and adds payloads to the diagram.
Does Volley capture webhooks?+
Yes—create a webhook inbox, point services like Stripe or GitHub to it, and Volley draws the events as a sequence diagram.
Can AI agents read and write Volley diagrams?+
Any chat assistant can generate diagrams via the /llms.txt primer, and coding agents can use the CLI, HTTP API or MCP server to check and render them.
How do I embed a diagram in a README?+
Save the diagram and copy its README embed URL; the SVG updates automatically when the diagram changes.
What happens if I exceed the free limits?+
Volley notifies you at the limit and offers an upgrade to Pro; the editor continues to work.
Summarized by DevHunt from volley.sh · Oct 20, 2026. Details may change; check the official site.
