Add Notion Webhook Support

[Prateek32177]

We want to add webhook support for Notion in tern. Notion sends events for database changes, page updates, and more via integrations.

Tasks

Webhook Handler

• Implement /src/platforms/notion.ts.
• Normalize payloads into tern’s event format.

Platform Config

• Add platformConfigs.notion with supported events (e.g., database/updated, page/updated, database/created).

Test Cases

• Add JSON fixtures for 3+ events (database updated, page updated, database created).
• Write Jest tests in /tests/notion.test.ts.

Docs

• Update /docs/platforms.md with setup steps.
• Mention manual webhook verification steps. See Notion Webhook Verification Docs

Acceptance Criteria

• Notion handler implemented
• Manual webhook verification supported
• Tests with 3+ event types
• Docs updated

Final Integration Testing

To complete a new platform integration in Tern, please ensure the signature verification works correctly:

• Trigger a webhook event from the platform’s dashboard (use the “Send Test Event” option if available).
• Verify the signature using the platform’s signing secret / HMAC.
• The event should pass verification if the signature is correct.
• The event should fail verification if the signature is invalid.

Add a test case in Jest covering both valid and invalid signature scenarios.

This ensures that the integration reliably validates incoming webhook events before processing.

Helpful Links: Notion Webhooks Docs

[rakshitjain23]

i want to work on this pls assign it to me @Prateek32177

[Prateek32177]

Hi @rakshitjain23
can you please confirm if you are attempting this issue?

[rakshitjain23]

@Prateek32177 i can work on UI frontend part.

[Prateek32177]

@rakshitjain23 this task is purely related to typescript no frontend involved,
if you want you can check this issue Hookflo/TernUI#2 on other repo.
Its related to addition of live demo section on https://tern.hookflo.com/