hdls Events

hdls Events is a headless, MCP-native event & webhook stream backend. It manages events, streams, and webhooks, operated entirely through named tools your AI assistant calls. It stands in for tools like Segment, Svix — same job, no UI to run.

💬 Just ask

"Track a 'user.signed_up' event and add a webhook so my app gets notified." · "Show me what fired this hour."

You don't call these tools yourself — just tell your assistant in plain English. Everything below is the reference for when you (or your assistant) want the exact details.

How Events is organized

The headline entity is the event — start there, then attach the rest to it. Records connect by reference: an endpoint links to a stream. The event table is an append-only timeline — every change and note lands there and is never edited or deleted.

Entity	Purpose	Relates to
`event`	Append-only immutable ingested event (primary high-volume entity); fans out to endpoint deliveries.	`stream`
`stream`	A named event stream/source/topic that events are published into and endpoints subscribe to.	—
`endpoint`	A webhook subscription: an HTTPS URL that receives events from a stream, optionally filtered by type.	`stream`
`delivery`	Append-only per-attempt webhook delivery log enabling retry, replay and observability.	`event`, `endpoint`

Common workflows

Each line is one real sequence of tool calls — your assistant chains them for you.

Set up an event end to end: create_webhook → track_event

Tools

Call these at https://hdls.ai/api/mcp/events. Required fields you must supply; optional fields refine the call. You never pass tenant_id — it is stamped server-side.

Create

Tool	What it does	Required	Optional
`create_webhook`	Create webhook.	`stream_id`, `event_type`	`source`, `idempotency_key`, `payload`, `occurred_at`, `data`

Update & advance

Tool	What it does	Required	Optional
`track_event`	Track event.	`stream_id`, `event_type`	`source`, `idempotency_key`, `payload`, `occurred_at`, `data`
`replay_event`	Replay an event.	`id`	—

Find & read

Tool	What it does	Required	Optional
`query_events`	Query the event stream.	—	—
`list_streams`	Search streams by free-text and/or column filters (tenant-scoped, paginated).	—	`search`, `filters`, `limit`, `orderBy`

Field lists come from the product's live schema and are embedded in each tool's own description — read the tool description for the exact, current fields.

Field reference

Every field you can set on each record. Custom fields you add live alongside these in data.

`stream`

Field	Type	Required	Notes
`key`	text	Yes
`name`	text	Yes	Display name.
`description`	text
`is_active`	true / false
`data`	json		Free-form JSON — custom fields live here.

`endpoint`

Field	Type	Required	Notes
`stream_id`	id	Yes	Links to a `stream`.
`url`	text	Yes
`secret`	text
`event_types`	list
`is_active`	true / false
`rate_limit`	number
`data`	json		Free-form JSON — custom fields live here.

Tailor it with custom fields

Add fields without a schema change. add_custom_field defines one, list_custom_fields shows what's defined, and promote_custom_field (admin) shares a personal field with the whole workspace. The value lives in each row's data (JSON) and is set and read through the normal record tools. See Products, tools & custom fields for the full model.

Roles & safety

Tenant isolation is automatic. Your credential is pinned to one workspace; you never pass tenant_id, and you can only ever see your own data (enforced by Postgres row-level security).
Role-gated. Permissions run reader < member < admin < owner. Installing a product and promoting a custom field workspace-wide need admin/owner.
History is append-only. The event timeline is never edited or deleted — it's your audit trail.

Connect

On the concierge (https://hdls.ai/api/mcp), run install_product({ slug: "events" }) (admin/owner) to enable it for your workspace, then add https://hdls.ai/api/mcp/events as a connector in your assistant — see Connect your assistant.

A worked example

The literal call your assistant makes when you ask it to create the headline record:

Tool: create_webhook
Arguments: {
  "stream_id": "<stream-id>",
  "event_type": "example"
}

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