# Event Catalog API

- **Base URL:** `https://event-catalog.sls.epilot.io`
- **Full API Docs:** [https://docs.epilot.io/api/event-catalog](https://docs.epilot.io/api/event-catalog)

## Usage

```ts
import { epilot } from '@epilot/sdk'

epilot.authorize(() => '<token>')
const { data } = await epilot.eventCatalog.listEvents(...)
```

### Tree-shakeable import

```ts
import { getClient, authorize } from '@epilot/sdk/event-catalog'

const eventCatalogClient = getClient()
authorize(eventCatalogClient, () => '<token>')
const { data } = await eventCatalogClient.listEvents(...)
```

## Operations

**Event Catalog**
- [`listEvents`](#listevents)
- [`getEvent`](#getevent)
- [`patchEvent`](#patchevent)
- [`getEventJSONSchema`](#geteventjsonschema)
- [`getEventExample`](#geteventexample)
- [`listEventVersions`](#listeventversions)
- [`searchEventHistory`](#searcheventhistory)
- [`searchEventHistoryV2`](#searcheventhistoryv2)
- [`getHistoricalEvent`](#gethistoricalevent)
- [`triggerEvent`](#triggerevent)

**Schemas**
- [`EventConfigBase`](#eventconfigbase)
- [`EventConfig`](#eventconfig)
- [`UpdateEventPayload`](#updateeventpayload)
- [`PrimitiveField`](#primitivefield)
- [`ContextEntity`](#contextentity)
- [`AttachmentField`](#attachmentfield)
- [`SchemaField`](#schemafield)
- [`CommonEventMetadata`](#commoneventmetadata)
- [`EventJsonSchema`](#eventjsonschema)
- [`Event`](#event)
- [`EventSummary`](#eventsummary)
- [`GraphDefinition`](#graphdefinition)
- [`GraphNode`](#graphnode)
- [`GraphEdge`](#graphedge)
- [`EntityOperationTrigger`](#entityoperationtrigger)
- [`SearchOptions`](#searchoptions)
- [`SearchOptionsV2`](#searchoptionsv2)
- [`FieldsParam`](#fieldsparam)
- [`TriggerEventPayload`](#triggereventpayload)
- [`TriggerEventResponse`](#triggereventresponse)
- [`EventAttachment`](#eventattachment)
- [`FieldChange`](#fieldchange)
- [`VersionMeta`](#versionmeta)
- [`EventVersionRegistrySummary`](#eventversionregistrysummary)

### `listEvents`

Retrieve list of available business events

`GET /v1/events`

```ts
const { data } = await client.listEvents()
```

<details>
<summary>Response</summary>

```json
{
  "results": [
    {
      "event_name": "AddMeterReading",
      "event_title": "Add Meter Reading",
      "event_description": "Triggered when a new meter reading is added",
      "event_version": "1.0",
      "event_status": "active",
      "event_tags": ["builtin", "metering", "erp"],
      "schema_fields": {},
      "entity_graph": {
        "nodes": [
          {
            "id": "contact",
            "schema": "contact",
            "cardinality": "one",
            "fields": ["_id", "_title", "first_name", "account", "!account.*._files", "**._product"]
          }
        ],
        "edges": [
          {
            "from": "contact",
            "to": "billing_account"
          }
        ]
      },
      "entity_operation": {
        "operation": ["createEntity", "updateEntity"],
        "schema": ["contact", "contract", "order"],
        "attribute": ["email", "phone", "status"],
        "purpose": ["Kündigung", "Umzug/Auszug"]
      },
      "enabled": true,
      "auto_trigger": true,
      "automation_trigger": true
    }
  ]
}
```

</details>

---

### `getEvent`

Retrieve the configuration of a specific business event

`GET /v1/events/{event_name}`

```ts
const { data } = await client.getEvent({
  event_name: 'example',
})
```

<details>
<summary>Response</summary>

```json
{
  "event_name": "AddMeterReading",
  "event_title": "Add Meter Reading",
  "event_description": "Triggered when a new meter reading is added",
  "event_version": "1.0",
  "event_status": "active",
  "event_tags": ["builtin", "metering", "erp"],
  "schema_fields": {},
  "entity_graph": {
    "nodes": [
      {
        "id": "contact",
        "schema": "contact",
        "cardinality": "one",
        "fields": ["_id", "_title", "first_name", "account", "!account.*._files", "**._product"]
      }
    ],
    "edges": [
      {
        "from": "contact",
        "to": "billing_account"
      }
    ]
  },
  "entity_operation": {
    "operation": ["createEntity", "updateEntity"],
    "schema": ["contact", "contract", "order"],
    "attribute": ["email", "phone", "status"],
    "purpose": ["Kündigung", "Umzug/Auszug"]
  },
  "enabled": true,
  "auto_trigger": true,
  "automation_trigger": true
}
```

</details>

---

### `patchEvent`

Update the configuration of a specific business event for the organization

`PATCH /v1/events/{event_name}`

```ts
const { data } = await client.patchEvent(
  {
    event_name: 'example',
  },
  {
    event_name: 'AddMeterReading',
    event_title: 'Add Meter Reading',
    event_description: 'Triggered when a new meter reading is added',
    event_version: '1.0',
    event_status: 'active',
    event_tags: ['builtin', 'metering', 'erp'],
    schema_fields: {},
    entity_graph: {
      nodes: [
        {
          id: 'contact',
          schema: 'contact',
          cardinality: 'one',
          fields: ['_id', '_title', 'first_name', 'account', '!account.*._files', '**._product']
        }
      ],
      edges: [
        {
          from: 'contact',
          to: 'billing_account'
        }
      ]
    },
    entity_operation: {
      operation: ['createEntity', 'updateEntity'],
      schema: ['contact', 'contract', 'order'],
      attribute: ['email', 'phone', 'status'],
      purpose: ['Kündigung', 'Umzug/Auszug']
    },
    enabled: true,
    auto_trigger: true,
    automation_trigger: true
  },
)
```

<details>
<summary>Response</summary>

```json
{
  "event_name": "AddMeterReading",
  "event_title": "Add Meter Reading",
  "event_description": "Triggered when a new meter reading is added",
  "event_version": "1.0",
  "event_status": "active",
  "event_tags": ["builtin", "metering", "erp"],
  "schema_fields": {},
  "entity_graph": {
    "nodes": [
      {
        "id": "contact",
        "schema": "contact",
        "cardinality": "one",
        "fields": ["_id", "_title", "first_name", "account", "!account.*._files", "**._product"]
      }
    ],
    "edges": [
      {
        "from": "contact",
        "to": "billing_account"
      }
    ]
  },
  "entity_operation": {
    "operation": ["createEntity", "updateEntity"],
    "schema": ["contact", "contract", "order"],
    "attribute": ["email", "phone", "status"],
    "purpose": ["Kündigung", "Umzug/Auszug"]
  },
  "enabled": true,
  "auto_trigger": true,
  "automation_trigger": true
}
```

</details>

---

### `getEventJSONSchema`

Retrieve the JSON Schema of a specific business event. Pass an optional
`Epilot-Event-Version` header to retrieve a specific version's schema;
when omitted, the event's latest version is returned.

`GET /v1/events/{event_name}/json_schema`

```ts
const { data } = await client.getEventJSONSchema({
  event_name: 'example',
  Epilot-Event-Version: 'example',
})
```

<details>
<summary>Response</summary>

```json
{
  "type": "object",
  "properties": {
    "_org_id": {
      "type": "string",
      "description": "epilot tenant/organization ID"
    },
    "_event_time": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp when event occurred"
    },
    "_event_id": {
      "type": "string",
      "description": "Unique event identifier (ULID)"
    },
    "_event_name": {
      "type": "string",
      "description": "Event name from catalog"
    },
    "_event_version": {
      "type": "string",
      "description": "Event payload version (MAJOR.MINOR)"
    },
    "_event_source": {
      "type": "string",
      "description": "Source that triggered the event"
    },
    "reading_value": {
      "type": "number",
      "description": "The meter reading value"
    },
    "reading_date": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp when reading was taken"
    },
    "read_by": {
      "type": "string",
      "description": "Name or identifier of who submitted the reading"
    },
    "reason": {
      "type": "string",
      "enum": ["regular", "move-in", "move-out", "supplier-change", "correction", "final"],
      "description": "Reason for the meter reading"
    },
    "direction": {
      "type": "string",
      "enum": ["feed-in", "feed-out"],
      "description": "Direction of energy flow"
    },
    "source": {
      "type": "string",
      "enum": ["portal", "360", "api", "automation"],
      "description": "Source system where reading was submitted"
    },
    "meter_id": {
      "type": "string",
      "format": "uuid",
      "description": "Entity ID of the meter"
    },
    "counter_id": {
      "type": "string",
      "format": "uuid",
      "description": "Entity ID of the meter counter"
    },
    "meter_number": {
      "type": "string",
      "description": "Human-readable meter number"
    },
    "obis_number": {
      "type": "string",
      "description": "OBIS code of the counter"
    },
    "unit": {
      "type": "string",
      "description": "Unit of measurement (e.g., kWh, m3)"
    },
    "customer_id": {
      "type": "string",
      "format": "uuid",
      "description": "Entity ID of the customer"
    },
    "contract_id": {
      "type": "string",
      "format": "uuid",
      "description": "Entity ID of the contract"
    },
    "user_id": {
      "type": "string",
      "description": "ID of the user who submitted the reading"
    },
    "user_email": {
      "type": "string",
      "format": "email",
      "description": "Email of the user who submitted the reading"
    }
  },
  "required": ["_org_id", "_event_time", "_event_id", "_event_name", "_event_version", "_event_source", "reading_value", "reading_date", "read_by", "reason", "direction", "source", "meter_id", "counter_id", "meter_number", "obis_number", "unit", "customer_id", "contract_id"]
}
```

</details>

---

### `getEventExample`

Generate a sample event payload based on the event's JSON Schema. Pass an
optional `Epilot-Event-Version` header to generate the example for a
specific version; when omitted, the event's latest versio

`GET /v1/events/{event_name}/example`

```ts
const { data } = await client.getEventExample({
  event_name: 'example',
  Epilot-Event-Version: 'example',
})
```

<details>
<summary>Response</summary>

```json
{}
```

</details>

---

### `listEventVersions`

List every known version of an event, along with the `latest`
and the set of currently `active` versions. See §3.2 of the
Event Payload Versioning RFC.

`GET /v1/events/{event_name}/versions`

```ts
const { data } = await client.listEventVersions({
  event_name: 'example',
})
```

<details>
<summary>Response</summary>

```json
{
  "event_name": "MeterReadingAdded",
  "latest": "1.0",
  "versions": [
    {
      "version": "1.0",
      "released_at": "2025-11-15",
      "change_summary": "string",
      "change_notes": "string",
      "changes": [
        {
          "field": "reading",
          "op": "added",
          "type_old": "string",
          "type_new": "string"
        }
      ]
    }
  ]
}
```

</details>

---

### `searchEventHistory`

Paginated history of events

`POST /v1/events/{event_name}:history`

```ts
const { data } = await client.searchEventHistory(
  {
    event_name: 'example',
  },
  {
    limit: 10,
    cursor: {
      event_time: '2025-10-31 12:34:56',
      event_id: 'evt_1234567890abcdef'
    },
    timestamp: {
      from: '2025-10-01T00:00:00Z',
      to: '2025-10-31T23:59:59Z'
    },
    event_id: 'evt_1234567890abcdef'
  },
)
```

<details>
<summary>Response</summary>

```json
{
  "results": [
    {
      "_org_id": "org_123456",
      "_event_time": "2024-01-01T12:00:00Z",
      "_event_id": "01FZ4Z5FZ5FZ5FZ5FZ5FZ5FZ5F",
      "_event_name": "MeterReading",
      "_event_version": "1.0",
      "_event_source": "api",
      "_trigger_source_type": "api",
      "_trigger_source": "user_123456",
      "reading_value": 123.45,
      "reading_date": "2024-01-01T11:59:00Z",
      "read_by": "John Doe",
      "reason": "regular",
      "direction": "feed-out",
      "source": "portal",
      "meter_id": "550e8400-e29b-41d4-a716-446655440000",
      "counter_id": "660e8400-e29b-41d4-a716-446655440000",
      "meter_number": "MT123456789",
      "obis_number": "1-0:1.8.0",
      "unit": "kWh",
      "customer_id": "770e8400-e29b-41d4-a716-446655440000",
      "contract_id": "880e8400-e29b-41d4-a716-446655440000"
    }
  ],
  "next_cursor": {
    "event_time": "2025-10-31T12:34:56Z",
    "event_id": "evt_1234567890abcdef"
  }
}
```

</details>

---

### `searchEventHistoryV2`

Paginated history of events with projected/lightweight payload (v2).

`POST /v2/events/{event_name}:history`

```ts
const { data } = await client.searchEventHistoryV2(
  {
    event_name: 'example',
  },
  {
    limit: 10,
    cursor: {
      event_time: '2025-10-31 12:34:56',
      event_id: 'evt_1234567890abcdef'
    },
    timestamp: {
      from: '2025-10-01T00:00:00Z',
      to: '2025-10-31T23:59:59Z'
    },
    event_id: 'evt_1234567890abcdef',
    fields: ['_id', '_title', 'first_name', 'account', '!account.*._files', '**._product']
  },
)
```

<details>
<summary>Response</summary>

```json
{
  "results": [
    {
      "_org_id": "string",
      "_event_time": "1970-01-01T00:00:00.000Z",
      "_event_id": "string",
      "_event_name": "string",
      "_event_version": "1.0",
      "_event_source": "string",
      "_trigger_source_type": "api",
      "_trigger_source": "string",
      "_ack_id": "string"
    }
  ],
  "next_cursor": {
    "event_time": "2025-10-31T12:34:56Z",
    "event_id": "evt_1234567890abcdef"
  }
}
```

</details>

---

### `getHistoricalEvent`

Fetch a single historical event by id with full hydration

`GET /v2/events/{event_name}/history/{event_id}`

```ts
const { data } = await client.getHistoricalEvent({
  event_name: 'example',
  event_id: 'example',
})
```

<details>
<summary>Response</summary>

```json
{
  "_org_id": "org_123456",
  "_event_time": "2024-01-01T12:00:00Z",
  "_event_id": "01FZ4Z5FZ5FZ5FZ5FZ5FZ5FZ5F",
  "_event_name": "MeterReading",
  "_event_version": "1.0",
  "_event_source": "api",
  "_trigger_source_type": "api",
  "_trigger_source": "user_123456",
  "reading_value": 123.45,
  "reading_date": "2024-01-01T11:59:00Z",
  "read_by": "John Doe",
  "reason": "regular",
  "direction": "feed-out",
  "source": "portal",
  "meter_id": "550e8400-e29b-41d4-a716-446655440000",
  "counter_id": "660e8400-e29b-41d4-a716-446655440000",
  "meter_number": "MT123456789",
  "obis_number": "1-0:1.8.0",
  "unit": "kWh",
  "customer_id": "770e8400-e29b-41d4-a716-446655440000",
  "contract_id": "880e8400-e29b-41d4-a716-446655440000"
}
```

</details>

---

### `triggerEvent`

Explicitly trigger an event by providing input field values and an optional entity seed
for graph hydration. The event must be enabled for the organization.

`POST /v1/events/{event_name}:trigger`

```ts
const { data } = await client.triggerEvent(
  {
    event_name: 'example',
  },
  {
    seed: {
      entity_id: '3fa85f64-5717-4562-b3fc-2c963f66afa6',
      node_id: 'string'
    },
    fields: {},
    skip_hydration: ['string'],
    _trigger_source_type: 'string',
    _trigger_source: 'string'
  },
)
```

<details>
<summary>Response</summary>

```json
{
  "success": true,
  "event_id": "string",
  "event_bridge_event_id": "string"
}
```

</details>

---

## Schemas

### `EventConfigBase`

Base properties shared between EventConfig and UpdateEventPayload

```ts
type EventConfigBase = {
  event_name?: string
  event_title?: string
  event_description?: string
  event_version?: string
  event_status?: "active" | "deprecated" | "draft" | "disabled"
  event_tags?: string[]
  schema_fields?: Record<string, {
    json_schema: object
    required?: boolean
    graph_source?: string
  } | {
    entity_schema: string
    required?: boolean
  } | {
    items: {
      entity_id: { ... }
      filename?: { ... }
      mime_type?: { ... }
      size_bytes?: { ... }
      s3ref?: { ... }
      version_index: { ... }
      readable_size?: { ... }
    }
    required?: boolean
  }>
  entity_graph?: {
    nodes: Array<{
      id: { ... }
      schema: { ... }
      cardinality?: { ... }
      fields?: { ... }
    }>
    edges: Array<{
      from: { ... }
      to: { ... }
    }>
  }
  entity_operation?: {
    operation: "createEntity" | "updateEntity" | "deleteEntity"[]
    schema: string[]
    attribute?: string[]
    purpose?: string[]
  }
  enabled?: boolean
  auto_trigger?: boolean
  automation_trigger?: boolean
}
```

### `EventConfig`

Event configuration with required fields

```ts
type EventConfig = {
  event_name: string
  event_title?: string
  event_description?: string
  event_version: string
  event_status?: "active" | "deprecated" | "draft" | "disabled"
  event_tags?: string[]
  schema_fields: Record<string, {
    json_schema: object
    required?: boolean
    graph_source?: string
  } | {
    entity_schema: string
    required?: boolean
  } | {
    items: {
      entity_id: { ... }
      filename?: { ... }
      mime_type?: { ... }
      size_bytes?: { ... }
      s3ref?: { ... }
      version_index: { ... }
      readable_size?: { ... }
    }
    required?: boolean
  }>
  entity_graph?: {
    nodes: Array<{
      id: { ... }
      schema: { ... }
      cardinality?: { ... }
      fields?: { ... }
    }>
    edges: Array<{
      from: { ... }
      to: { ... }
    }>
  }
  entity_operation?: {
    operation: "createEntity" | "updateEntity" | "deleteEntity"[]
    schema: string[]
    attribute?: string[]
    purpose?: string[]
  }
  enabled?: boolean
  auto_trigger?: boolean
  automation_trigger?: boolean
}
```

### `UpdateEventPayload`

Payload for updating an event configuration.
Accepts the same fields as EventConfig (all optional for PATCH).
Currently `enabled` and `auto_trigger` fields are processed.


```ts
type UpdateEventPayload = {
  event_name?: string
  event_title?: string
  event_description?: string
  event_version?: string
  event_status?: "active" | "deprecated" | "draft" | "disabled"
  event_tags?: string[]
  schema_fields?: Record<string, {
    json_schema: object
    required?: boolean
    graph_source?: string
  } | {
    entity_schema: string
    required?: boolean
  } | {
    items: {
      entity_id: { ... }
      filename?: { ... }
      mime_type?: { ... }
      size_bytes?: { ... }
      s3ref?: { ... }
      version_index: { ... }
      readable_size?: { ... }
    }
    required?: boolean
  }>
  entity_graph?: {
    nodes: Array<{
      id: { ... }
      schema: { ... }
      cardinality?: { ... }
      fields?: { ... }
    }>
    edges: Array<{
      from: { ... }
      to: { ... }
    }>
  }
  entity_operation?: {
    operation: "createEntity" | "updateEntity" | "deleteEntity"[]
    schema: string[]
    attribute?: string[]
    purpose?: string[]
  }
  enabled?: boolean
  auto_trigger?: boolean
  automation_trigger?: boolean
}
```

### `PrimitiveField`

A primitive JSON Schema field definition

```ts
type PrimitiveField = {
  json_schema: object
  required?: boolean
  graph_source?: string
}
```

### `ContextEntity`

```ts
type ContextEntity = {
  entity_schema: string
  required?: boolean
}
```

### `AttachmentField`

A schema field representing file attachments associated with the event.
Present in schema_fields for events tagged with "attachment".


```ts
type AttachmentField = {
  items: {
    entity_id: string // uuid
    filename?: string
    mime_type?: string
    size_bytes?: number
    s3ref?: {
      bucket: { ... }
      key: { ... }
    }
    version_index: number
    readable_size?: string
  }
  required?: boolean
}
```

### `SchemaField`

```ts
type SchemaField = {
  json_schema: object
  required?: boolean
  graph_source?: string
} | {
  entity_schema: string
  required?: boolean
} | {
  items: {
    entity_id: string // uuid
    filename?: string
    mime_type?: string
    size_bytes?: number
    s3ref?: {
      bucket: { ... }
      key: { ... }
    }
    version_index: number
    readable_size?: string
  }
  required?: boolean
}
```

### `CommonEventMetadata`

Common metadata fields present in all event payloads

```ts
type CommonEventMetadata = object
```

### `EventJsonSchema`

JSON Schema declaring the event payload structure

```ts
type EventJsonSchema = object
```

### `Event`

An event instance in the event history

```ts
type Event = {
  _org_id: string
  _event_time: string // date-time
  _event_id: string
  _event_name: string
  _event_version: string
  _event_source: string
  _trigger_source_type?: string
  _trigger_source?: string
  _ack_id?: string
}
```

### `EventSummary`

A lightweight event summary returned by the v2 history endpoint.

Includes the standard `_*` metadata fields plus a projected subset of the
event payload. Hydrated entity objects (values carrying `_schema` or `_id`)
— and arrays of such objects — are reduced to reference stubs
`{_schema, _id, _title

```ts
type EventSummary = {
  _org_id: string
  _event_time: string // date-time
  _event_id: string
  _event_name: string
  _event_version: string
  _event_source: string
  _trigger_source_type?: string
  _trigger_source?: string
  _ack_id?: string
}
```

### `GraphDefinition`

Entity graph definition for resolving related entities

```ts
type GraphDefinition = {
  nodes: Array<{
    id: string
    schema: string
    cardinality?: "one" | "many"
    fields?: object
  }>
  edges: Array<{
    from: string
    to: string
  }>
}
```

### `GraphNode`

A node in the entity graph

```ts
type GraphNode = {
  id: string
  schema: string
  cardinality?: "one" | "many"
  fields?: object
}
```

### `GraphEdge`

An edge connecting two nodes in the graph

```ts
type GraphEdge = {
  from: string
  to: string
}
```

### `EntityOperationTrigger`

Configuration for triggering an event based on entity operations.

When an entity operation matches the configured criteria, the event will be triggered.
- On createEntity: the attribute must be present in the entity payload
- On updateEntity: the attribute must be in diff.added, diff.updated, or di

```ts
type EntityOperationTrigger = {
  operation: "createEntity" | "updateEntity" | "deleteEntity"[]
  schema: string[]
  attribute?: string[]
  purpose?: string[]
}
```

### `SearchOptions`

```ts
type SearchOptions = {
  limit?: number
  cursor?: {
    event_time?: string
    event_id?: string
  }
  timestamp?: {
    from?: string // date-time
    to?: string // date-time
  }
  event_id?: string
}
```

### `SearchOptionsV2`

Search options for the v2 history endpoint.

Extends `SearchOptions` with an optional `fields` projection. When `fields`
is omitted, the response includes all `_*` metadata plus all scalar payload
fields (and primitive arrays / empty objects/arrays) after entity stripping.
When `fields` is provided,

```ts
type SearchOptionsV2 = {
  limit?: number
  cursor?: {
    event_time?: string
    event_id?: string
  }
  timestamp?: {
    from?: string // date-time
    to?: string // date-time
  }
  event_id?: string
  fields?: string[]
}
```

### `FieldsParam`

List of entity fields to include or exclude in the response

Use ! to exclude fields, e.g. `!_id` to exclude the `_id` field.

Globbing and globstart (**) is supported for nested fields.


```ts
type FieldsParam = string[]
```

### `TriggerEventPayload`

Payload for explicitly triggering an event via API

```ts
type TriggerEventPayload = {
  seed?: {
    entity_id: string // uuid
    node_id: string
  }
  fields?: Record<string, unknown>
  skip_hydration?: string[]
  _trigger_source_type?: string
  _trigger_source?: string
}
```

### `TriggerEventResponse`

Response from triggering an event

```ts
type TriggerEventResponse = {
  success: boolean
  event_id: string
  event_bridge_event_id?: string
}
```

### `EventAttachment`

A file attachment associated with an event

```ts
type EventAttachment = {
  entity_id: string // uuid
  filename?: string
  mime_type?: string
  size_bytes?: number
  s3ref?: {
    bucket: string
    key: string
  }
  version_index: number
  readable_size?: string
}
```

### `FieldChange`

A field-level change descriptor. Powers the declarative half of the
version DSL.


```ts
type FieldChange = {
  field: string
  op: "added" | "removed" | "type-changed"
  type_old?: string
  type_new?: string
}
```

### `VersionMeta`

One entry of an event's version timeline.

```ts
type VersionMeta = {
  version: string
  released_at: string
  change_summary: string
  change_notes?: string
  changes: Array<{
    field: string
    op: "added" | "removed" | "type-changed"
    type_old?: string
    type_new?: string
  }>
}
```

### `EventVersionRegistrySummary`

Summary of an event's version timeline returned by
`GET /v1/events/{event_name}/versions`.


```ts
type EventVersionRegistrySummary = {
  event_name: string
  latest: string
  versions: Array<{
    version: string
    released_at: string
    change_summary: string
    change_notes?: string
    changes: Array<{
      field: { ... }
      op: { ... }
      type_old?: { ... }
      type_new?: { ... }
    }>
  }>
}
```