> ## Documentation Index
> Fetch the complete documentation index at: https://docs.allium.so/llms.txt
> Use this file to discover all available pages before exploring further.

# List available sources

> Lists the chains and entities available to use as a Beam pipeline source.

```
GET /api/v1/beam/sources
```

Returns the catalog of chains/entities currently available to use as a Beam pipeline source, along with whether each one is served via Kafka or PubSub. Requires a Beam-enabled organization and an API key with the `custom_transforms` feature.

```bash theme={null}
curl -X GET https://api.allium.so/api/v1/beam/sources \
  -H "X-API-Key: ${ALLIUM_API_KEY}"
```

**Response:**

```json theme={null}
{
  "sources": [
    {
      "chain": "ethereum",
      "entity": "log",
      "zerolag": false,
      "consolidated": true,
      "default_size": "S",
      "source_type": "pubsub"
    },
    {
      "chain": "hyperliquid",
      "entity": "order",
      "zerolag": false,
      "consolidated": false,
      "default_size": "M",
      "source_type": "kafka"
    }
  ]
}
```

| Field          | Description                                                        |
| :------------- | :----------------------------------------------------------------- |
| `chain`        | Blockchain identifier (use as `chain` in a pipeline source config) |
| `entity`       | Entity type (use as `entity` in a pipeline source config)          |
| `zerolag`      | Whether this source emits pre-finality data                        |
| `consolidated` | Internal indicator of the source's PubSub topic layout             |
| `default_size` | Suggested pod size for a pipeline using this source                |
| `source_type`  | `"kafka"` or `"pubsub"` — the transport this source is served over |


## OpenAPI

````yaml _openapi/beam-api.json GET /api/v1/beam/sources
openapi: 3.1.0
info:
  title: Allium Beam API
  description: Allium Beam — managed streaming pipelines on top of Allium Datastreams.
  version: 1.0.0
servers:
  - url: https://api.allium.so
security: []
paths:
  /api/v1/beam/sources:
    get:
      tags:
        - BEAM
      summary: List Beam Available Sources Handler
      operationId: list_beam_available_sources_handler_api_v1_beam_sources_get
      parameters:
        - name: chain
          in: query
          required: false
          schema:
            type: string
            title: Chain
        - name: entity
          in: query
          required: false
          schema:
            type: string
            title: Entity
        - name: zerolag
          in: query
          required: false
          schema:
            type: boolean
            title: Zerolag
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BeamAvailableSourcesResponse'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      security:
        - APIKeyBearer: []
components:
  schemas:
    BeamAvailableSourcesResponse:
      properties:
        sources:
          items:
            $ref: '#/components/schemas/BeamAvailableSource'
          type: array
          title: Sources
      type: object
      required:
        - sources
      title: BeamAvailableSourcesResponse
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    BeamAvailableSource:
      properties:
        chain:
          type: string
          title: Chain
        entity:
          type: string
          title: Entity
        zerolag:
          type: boolean
          title: Zerolag
        default_size:
          type: string
          title: Default Size
        source_type:
          type: string
          title: Source Type
      type: object
      required:
        - chain
        - entity
        - zerolag
        - default_size
        - source_type
      title: BeamAvailableSource
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError
  securitySchemes:
    APIKeyBearer:
      type: apiKey
      in: header
      name: X-API-KEY

````