Concepts

Inboxes belong to the workspace you are signed into. Teammates in that workspace can open the same Inboxes from the app; people outside cannot manage them. The catch URL itself stays callable without signing in — that is how webhooks work.

Workspace boundary

Building blocks

Term Meaning Typical home in the app
Inbox A named session that collects inbound HTTP requests Capture (/capture/:inboxId)
Catch URL Public inbound address (/i/{inbox-id}) partners call Context bar · Help
Request One captured HTTP call (method, URL, headers, body, timing) Sidebar list → request detail
Mock response Default status, headers, body, and optional delay Spanline returns to callers Console → Response tab
Replay Re-send a captured request from your browser (optionally edited) Request detail → Replay
Project (optional) Durable product identity when creating an Inbox New Inbox modal in the product

Catch URL vs the Capture page

What Purpose
Catch URL (/i/{inbox-id}) Where partners send webhooks / HTTP calls
Capture page (/capture/{inbox-id}) Where your team inspects and manages those requests

They are different addresses on purpose. Share only the catch URL with external systems.

What Spanline stores for each request

You can also set a default mock response for the Inbox so callers always get a predictable reply while you debug.

Override the response status in the URL

Append a status segment to the catch path for a one-off response:

https://api.spanline.dev/i/<your-inbox-id>/404   → respond with HTTP 404

Useful when a partner needs to test error handling. The context bar may offer a quick 404 toggle for the same effect.

Live updates

New requests show up in the Inbox as they arrive — you usually do not need to refresh the page. Spanline subscribes over a live channel while the Inbox is open.

Console tabs (in-page)

Capture does not use product-area scene tabs (Overview, Scenarios, …). Inside an Inbox you work across:

Tab / area Role
Inspect Request list context, empty listen hero, or request inspector
Response Default mock response editor and presets
Request inspector Body · Headers · Query · Cookies · Auth · Meta

Roles (workspace)

Role Typical access
Viewer Open Capture and inspect requests
Member Create Inboxes, edit mock responses, replay, delete requests
Admin / owner Same as member; manage workspace membership

Exact labels follow your workspace membership. If a control is disabled, ask an admin — it is usually a role or plan limit, not a product bug.

Limits

Your deployment may cap stored requests per Inbox or maximum body size. Limits appear in Help when configured. Clear older requests or delete the Inbox when you hit storage caps.