Composer in depth

Every control and text this screen shows, in screen order. The list is read from the demo by a crawl, and CI fails when the screen changes without its entry here.

Webhooks > Composer writes a webhook request by hand, or from any template, and sends it to an endpoint.

The screen as a whole: Composer and saved deliveries.

The numbers match the entries below. The picture shows the first screenful; controls further down, and texts, have no marker.

On the screenCopy Anchor Link

1. ComposerCopy Anchor Link

Heading.

• What it does: Names the screen, in the header and above the form.

2. Read the Composer guideCopy Anchor Link

Link.

• What it does: Opens this screen's page in the user guide, in a new tab.
• Links to: Composer and saved deliveries.

3. Write a webhook request by hand, start from any template, and send it to an endpoint.Copy Anchor Link

Text.

• What it does: Explains the screen.

4. Send toCopy Anchor Link

Drop-down.

• What it does: The endpoint the request goes to.
• Links to: Endpoints.

5. Its secret signs the request.Copy Anchor Link

Text.

• What it does: Explains that the endpoint's secret signs it.

6. PresetCopy Anchor Link

Drop-down.

• What it does: A template to start from: it fills the method, headers and body, which you can then change.

7. A template fills the method, headers and body, ready to edit.Copy Anchor Link

Text.

• What it does: Explains Preset.

8. MethodCopy Anchor Link

Drop-down.

• What it does: The HTTP method.

9. URLCopy Anchor Link

Field.

• What it does: A URL for this request only; it may hold {{ }} templates.

10. Leave empty to use the endpoint's URL.Copy Anchor Link

Text.

• What it does: Explains the URL field.

11. None. Added to the URL, URL-encoded.Copy Anchor Link

Text.

• What it does: The query parameters; none yet.

12. Add query paramCopy Anchor Link

Button.

• What it does: Adds a query parameter.

13. None besides Content-Type and the signature headers.Copy Anchor Link

Text.

• What it does: The extra headers; none yet.

14. Add headerCopy Anchor Link

Button.

• What it does: Adds a header.

15. TemplateCopy Anchor Link

Choice.

• What it does: The body comes from a webhook template.

16. FieldsCopy Anchor Link

Choice.

• What it does: The body is built from name and value fields.

17. RawCopy Anchor Link

Choice.

• What it does: The body is text you write, with templates inside.

18. NoneCopy Anchor Link

Choice.

• What it does: No body.

19. Content typeCopy Anchor Link

Drop-down.

• What it does: The raw body's Content-Type.

20. InsertCopy Anchor Link

Button.

• What it does: Inserts a value, function or filter at the cursor, from the template reference.

21. Raw bodyCopy Anchor Link

Field.

• What it does: The body, in the template language.

22. Type {{ to see what you can use; hover a value to see an example.Copy Anchor Link

Text.

• What it does: Explains the template suggestions.
• Links to: Template filters.

23. Strict An undefined value stops the delivery as render failed.Copy Anchor Link

Choice.

• What it does: A value that is not defined stops the send.

24. Lenient An undefined value renders empty, with a warning.Copy Anchor Link

Choice.

• What it does: A value that is not defined renders empty.

25. vars.reasonCopy Anchor Link

Field.

• What it does: A variable the template asks for on manual sends (here reason).
• Links to: Variables.

26. Asked for on manual sends.Copy Anchor Link

Text.

• What it does: Explains why the variable is asked for.

27. None. A value here wins over the endpoint and global value of that name, for this send only.Copy Anchor Link

Text.

• What it does: The variable overrides for this send; none yet.

28. Add overrideCopy Anchor Link

Button.

• What it does: Adds a variable value for this send only.

29. Preview withCopy Anchor Link

Drop-down.

• What it does: The event the preview renders with: a sample, or a recent real message.
• Same action elsewhere: REST POST /api/v1/webhooks/endpoints/preview, CLI sendmock webhook render, MCP sendmock_webhook_render

30. Copy rendered URLCopy Anchor Link

Button.

• What it does: Copies the URL as rendered.

31. Rendered headersCopy Anchor Link

Heading.

• What it does: The headers the request will carry, signature included.

32. Rendered bodyCopy Anchor Link

Heading.

• What it does: The body the request will carry.

33. Copy rendered bodyCopy Anchor Link

Button.

• What it does: Copies the rendered body.

34. SendCopy Anchor Link

Button.

• What it does: Sends the request now and shows the delivery it made, which you can then save.
• What it changes: Records a manual delivery in Webhooks > Deliveries.
• Errors: A template that does not render is refused with the reason.
• Same action elsewhere: REST POST /api/v1/webhooks/endpoints/{endpointId}/send, CLI sendmock webhook send, MCP sendmock_webhook_send

When the data cannot loadCopy Anchor Link

35. Could not load the endpoints to send to. Try againCopy Anchor Link

Message.

• What it does: Shown when the endpoints could not be loaded.
• Errors: Check SendMock is running, then press Try again.

36. Could not load the endpoints to send to.Copy Anchor Link

Text.

• What it does: The message inside the alert.

37. Try againCopy Anchor Link

Button.

• What it does: Loads the endpoints again.
• Same action elsewhere: REST GET /api/v1/webhooks/endpoints, CLI sendmock webhook endpoint list, MCP sendmock_webhook_endpoint_list