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

# Get a memory layer

> One layer's configuration and entry count. The entries themselves live on a separate read.

Read one [memory layer](/docs/api-reference/memoryservice/list-memory-layers): its type, description, and how many entries it holds. Not the entries, those you [list](/docs/api-reference/memoryservice/list-memory-entries) or [get](/docs/api-reference/memoryservice/get-a-memory-entry-by-id) separately.

<CodeGroup>
  ```typescript TypeScript theme={null}
  const layer = await client.memoryLayers.retrieve(layerId, { workspaceId });

  console.log(layer.spec.type);         // 'MEMORY_LAYER_TYPE_SKILLS'
  console.log(layer.spec.description);  // 'Support policies'
  console.log(layer.info?.entryCount);  // 12
  ```

  ```go Go theme={null}
  layer, err := client.MemoryLayers.Get(ctx, layerID, cadenya.MemoryLayerGetParams{
  	WorkspaceID: cadenya.String(workspaceID),
  })

  fmt.Println(layer.Spec.Type)        // 'MEMORY_LAYER_TYPE_SKILLS'
  fmt.Println(layer.Spec.Description) // 'Support policies'
  fmt.Println(layer.Info.EntryCount)  // 12
  ```

  ```ruby Ruby theme={null}
  layer = cadenya.memory_layers.retrieve(layer_id, workspace_id: workspace_id)

  puts layer.spec.type        # 'MEMORY_LAYER_TYPE_SKILLS'
  puts layer.spec.description # 'Support policies'
  puts layer.info.entry_count # 12
  ```

  ```bash cURL theme={null}
  curl "https://api.cadenya.com/v1/workspaces/${WORKSPACE_ID}/memory_layers/${MEMORY_LAYER_ID}" \
    -H "Authorization: Bearer ${CADENYA_API_KEY}"
  ```
</CodeGroup>

`info` returns on every read, `includeInfo` is a no-op here, and it carries `entryCount` and `createdBy`. `entryCount` is the cheap way to see how full a layer is without paging its entries.

## Two kinds of layer

`spec.type` tells you which, and it changes what the rest of `spec` means:

| Field                    | `MEMORY_LAYER_TYPE_SKILLS` | `MEMORY_LAYER_TYPE_EPISODIC`                                                  |
| ------------------------ | -------------------------- | ----------------------------------------------------------------------------- |
| Who made it              | You                        | Cadenya, per [episodic key](/docs/guides/memory-layers)                            |
| `systemManaged`          | `false`                    | `true`                                                                        |
| `agentId`, `episodicKey` | empty                      | the agent and key it belongs to                                               |
| `expiresAt`              | absent                     | the layer's [TTL](/docs/api-reference/memoryservice/update-a-memory-layer), if set |

A **skills** layer is the reusable knowledge you write and [assign](/docs/api-reference/agentvariationservice/attach-a-memory-layer-to-a-variation) to variations. An **episodic** layer is created and owned by Cadenya for an agent's [episodic memory](/docs/guides/memory-layers), so it carries an `agentId`, an `episodicKey`, and often an `expiresAt`. You do not create or edit an episodic layer directly.

## Fetch by your own ID

Memory layers are top-level workspace resources, so they take an [external ID](/docs/guides/use-your-own-ids):

```typescript theme={null}
const layer = await client.memoryLayers.retrieve('external_id:support-knowledge', { workspaceId });
```

A missing ID is a `404`.

## Related

<CardGroup cols={2}>
  <Card title="List memory layers" icon="layer-group" href="/docs/api-reference/memoryservice/list-memory-layers">
    Every layer, filterable by type.
  </Card>

  <Card title="List memory entries" icon="list" href="/docs/api-reference/memoryservice/list-memory-entries">
    The keys inside this layer, without the bodies.
  </Card>

  <Card title="Update a memory layer" icon="pen" href="/docs/api-reference/memoryservice/update-a-memory-layer">
    Rename it, or set an episodic TTL.
  </Card>

  <Card title="Memory layers" icon="brain" href="/docs/guides/memory-layers">
    Skills vs episodic, and the cascade.
  </Card>
</CardGroup>


## OpenAPI

````yaml get /v1/workspaces/{workspaceId}/memory_layers/{id}
openapi: 3.1.0
info:
  title: Cadenya API
  description: API for the Cadenya Agent Runtime platform.
  version: '1.0'
servers:
  - url: https://api.cadenya.com
    description: Production server
security:
  - bearerAuth: []
tags:
  - name: AIProviderKeyService
  - name: APIKeyService
    description: |-
      Issue, rotate, disable, and revoke a workspace's API keys. Every key
       belongs to exactly one workspace; the system-managed global account key is
       managed via GlobalAPIKeyService instead.
  - name: AccountService
    description: >-
      Manage the authenticated account. Accounts are the top-level
      organizational
       unit and contain one or more workspaces.
  - name: AgentScheduleService
    description: >-
      Manage recurring schedules attached to agents. Schedules trigger
      objectives
       on a cadence defined by AgentScheduleSpec.Schedule.
  - name: AgentService
    description: >-
      Manage AI agents within a workspace. Agents define AI behavior and tool
      access.
  - name: AgentVariationService
    description: >-
      Manage variations of an agent and their tool, sub-agent, and memory layer
      assignments.
  - name: GlobalAPIKeyService
    description: |-
      Manage the account's system-provisioned global API key. The global key is
       the only key that spans every workspace; it is created by the system and
       cannot be deleted, so the surface is retrieve, rotate, and the
       disable/enable kill switch.
  - name: MemoryService
    description: >-
      Manage memory layers and their entries. Layers are named containers that
      can
       be composed into an objective's memory cascade; entries are the keyed values
       within a layer. System-managed layers (e.g., episodic layers created by the
       runtime) cannot be mutated through this API.
  - name: ModelService
    description: |-
      Manage LLM models available to a workspace. Models represent provider and
       family pairs (e.g., "anthropic/claude-sonnet-4.6"). Workspaces are seeded
       with the supported models and you can enable or disable each one.
  - name: ObjectiveEventStreamsService
  - name: ObjectiveService
  - name: ProfilesService
    description: |-
      Operations on profiles, the account-level principals (users, API keys,
       system) that authenticate against the API.
  - name: SearchService
  - name: TenantService
    description: >-
      Read and erase tenants and the subjects under them. Tenants and subjects
      are
       created by assertion — on objective creation or widget session mint — never
       directly, so this service has no create or update: it exists to enumerate what
       assertions have produced, and to destroy it on request.
  - name: ToolService
    description: >-
      Manage tool sets and the tools they contain. Tool sets group related
      tools,
       and tools define specific capabilities available to agents.

       When a tool set is managed, only API key actors can modify its tools; human
       (profile) actors cannot.
  - name: UploadService
    description: |-
      Issue short-lived presigned URLs for direct client-to-object-storage
       uploads. Created uploads can be referenced by id when creating or updating
       resources that accept binary content (e.g., MemoryEntry).
  - name: WidgetService
    description: |-
      Manage embeddable chat widgets. A widget binds an agent to a globally
       unique hostname with a per-widget origin allowlist; browsers reach it with
       session tokens minted via WidgetSessionService.
  - name: WidgetSessionService
    description: >-
      Mint and manage widget sessions. Session creation is server-to-server
      only:
       the customer's backend authenticates its visitor, asserts tenant/subject
       context, attaches any per-visitor secrets, and receives a short-lived
       bearer token the browser uses against the widget host.
  - name: WorkspaceAdminService
    description: >-
      Administer workspaces across the account: create and archive workspaces
      and
       manage their membership. These operations are account-scoped and require the
       admin role (a token whose profile holds the WorkOS admin role); they live
       under /v1/account/workspaces rather than the workspace-scoped /v1/workspaces
       tree so an admin can manage any workspace in the account, including ones they
       are not themselves a member of.
  - name: WorkspaceSecretService
  - name: WorkspaceService
    description: |-
      Manage workspaces within an account. Workspaces provide organizational
       grouping and isolation for resources such as agents, tools, and API keys.

       This is the workspace-scoped, end-user surface. Administrative operations
       (create / archive workspaces, manage members) live in WorkspaceAdminService
       under /v1/account/workspaces and require the admin role.
paths:
  /v1/workspaces/{workspaceId}/memory_layers/{id}:
    get:
      tags:
        - MemoryService
        - Memory Layers
      summary: Get a memory layer by ID
      description: Retrieves a memory layer by ID from the workspace
      operationId: MemoryService_GetMemoryLayer
      parameters:
        - name: workspaceId
          in: path
          required: true
          schema:
            type: string
            example: workspace_01HXKD2E5NQM3T9AYWCF133E3Q
        - name: id
          in: path
          description: >-
            Memory layer ID. Accepts canonical memlyr_… form or
            external_id:<value> form.
          required: true
          schema:
            example: memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH
            type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MemoryLayer'
        default:
          description: Default error response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Status'
      x-codeSamples:
        - lang: JavaScript
          source: >-
            import Cadenya from '@cadenya/cadenya';


            const client = new Cadenya({
              apiKey: process.env['CADENYA_API_KEY'], // This is the default and can be omitted
            });


            const memoryLayer = await
            client.memoryLayers.retrieve('memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH', {
              workspaceId: 'workspace_01HXKD2E5NQM3T9AYWCF133E3Q',
            });


            console.log(memoryLayer.metadata);
        - lang: Python
          source: |-
            import os
            from cadenya import Cadenya

            client = Cadenya(
                api_key=os.environ.get("CADENYA_API_KEY"),  # This is the default and can be omitted
            )
            memory_layer = client.memory_layers.retrieve(
                id="memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH",
                workspace_id="workspace_01HXKD2E5NQM3T9AYWCF133E3Q",
            )
            print(memory_layer.metadata)
        - lang: Go
          source: "package main\n\nimport (\n\t\"context\"\n\t\"fmt\"\n\t\"go.cadenya.com/cadenya-go\"\n\t\"go.cadenya.com/cadenya-go/option\"\n)\n\nfunc main() {\n\tclient := cadenya.NewClient(\n\t\toption.WithAPIKey(\"My API Key\"),\n\t)\n\tmemoryLayer, err := client.MemoryLayers.Get(\n\t\tcontext.TODO(),\n\t\t\"memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH\",\n\t\tcadenya.MemoryLayerGetParams{\n\t\t\tWorkspaceID: cadenya.String(\"workspace_01HXKD2E5NQM3T9AYWCF133E3Q\"),\n\t\t},\n\t)\n\tif err != nil {\n\t\tpanic(err.Error())\n\t}\n\tfmt.Printf(\"%+v\\n\", memoryLayer.Metadata)\n}\n"
        - lang: Ruby
          source: |-
            require "cadenya"

            cadenya = Cadenya::Client.new(api_key: "My API Key")

            memory_layer = cadenya.memory_layers.retrieve(
              "memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH",
              workspace_id: "workspace_01HXKD2E5NQM3T9AYWCF133E3Q"
            )

            puts(memory_layer)
        - lang: CLI
          source: |-
            cadenya memory-layers retrieve \
              --api-key 'My API Key' \
              --workspace-id workspace_01HXKD2E5NQM3T9AYWCF133E3Q \
              --id memlyr_01HXKD2E5NQM3T9AYWCFFFBMJH
components:
  schemas:
    MemoryLayer:
      required:
        - metadata
        - spec
      type: object
      properties:
        metadata:
          $ref: '#/components/schemas/ResourceMetadata'
        spec:
          $ref: '#/components/schemas/MemoryLayerSpec'
        info:
          $ref: '#/components/schemas/MemoryLayerInfo'
      description: >-
        MemoryLayer is a named container of memory entries that can be composed
        into
         an objective's memory cascade. Layers are workspace-scoped resources. The layer
         type controls how its entries participate in the agent loop — see
         MemoryLayerType for details.

         See "Memory cascade composition" above for how layers compose at lookup time.
    Status:
      type: object
      properties:
        code:
          type: integer
          description: >-
            The status code, which should be an enum value of
            [google.rpc.Code][google.rpc.Code].
          format: int32
        message:
          type: string
          description: >-
            A developer-facing error message, which should be in English. Any
            user-facing error message should be localized and sent in the
            [google.rpc.Status.details][google.rpc.Status.details] field, or
            localized by the client.
        details:
          type: array
          items:
            $ref: '#/components/schemas/GoogleProtobufAny'
          description: >-
            A list of messages that carry the error details.  There is a common
            set of message types for APIs to use.
      description: >-
        The `Status` type defines a logical error model that is suitable for
        different programming environments, including REST APIs and RPC APIs. It
        is used by [gRPC](https://github.com/grpc). Each `Status` message
        contains three pieces of data: error code, error message, and error
        details. You can find out more about this error model and how to work
        with it in the [API Design
        Guide](https://cloud.google.com/apis/design/errors).
    ResourceMetadata:
      required:
        - id
        - accountId
        - workspaceId
        - name
        - profileId
        - createdAt
      type: object
      properties:
        id:
          readOnly: true
          type: string
          description: >-
            Unique identifier for the resource (prefixed ULID, e.g.,
            "agent_01HXK...")
        accountId:
          readOnly: true
          example: account_01HXKD2E5NQM3T9AYWCFTJHJVF
          type: string
          description: >-
            Account this resource belongs to for multi-tenant isolation
            (prefixed ULID)
        workspaceId:
          readOnly: true
          example: workspace_01HXKD2E5NQM3T9AYWCF133E3Q
          type: string
          description: >-
            Workspace this resource belongs to for organizational grouping
            (prefixed ULID)
        name:
          type: string
          description: >-
            Human-readable name for the resource (e.g., "Customer Support
            Agent", "Email Tool")
             Required for resources that users interact with directly
        externalId:
          type: string
          description: >-
            External ID for the resource (e.g., a workflow ID from an external
            system)
        labels:
          type: object
          additionalProperties:
            type: string
          description: |-
            Key-value pairs for categorization and filtering. Values are 0-63
             alphanumeric characters with "-", "_", or "." allowed between; keys
             follow the same shape and additionally accept an optional DNS-subdomain
             prefix (e.g. "cadenya.com/") of at most 253 characters.
             Examples: {"environment": "production", "team": "platform", "version": "v2"}
        profileId:
          readOnly: true
          example: profile_01HXKD2E5NQM3T9AYWCFS0AP08
          type: string
          description: ID of the actor (user or service account) that created this resource
        createdAt:
          readOnly: true
          type: string
          description: Timestamp when this resource was created
          format: date-time
        updatedAt:
          readOnly: true
          type: string
          description: Timestamp when this resource was last updated
          format: date-time
      description: >-
        Standard metadata for persistent, named resources (e.g., agents, tools,
        prompts)
    MemoryLayerSpec:
      required:
        - type
      type: object
      properties:
        type:
          enum:
            - MEMORY_LAYER_TYPE_UNSPECIFIED
            - MEMORY_LAYER_TYPE_EPISODIC
            - MEMORY_LAYER_TYPE_SKILLS
          type: string
          format: enum
        description:
          type: string
          description: |-
            Human-readable description of the layer's purpose. Encouraged for
             user-created layers; system-managed layers may have a generated description.
        systemManaged:
          readOnly: true
          type: boolean
          description: >-
            Server-set. True for layers managed by the system (e.g., episodic
            layers
             created automatically when an objective uses an episodic_key). System-managed
             layers cannot be assigned to objective cascades via the API and cannot be
             mutated by clients — their lifecycle is controlled entirely by the runtime.
        expiresAt:
          readOnly: true
          type: string
          description: >-
            For layers with a finite lifetime (e.g., episodic), the time at
            which the
             layer becomes eligible for cleanup. Set by the system; unset for
             persistent layers.
          format: date-time
        agentId:
          readOnly: true
          example: agent_01HXKD2E5NQM3T9AYWCFMGWT9Y
          type: string
          description: >-
            Server-set on episodic layers: the agent this layer belongs to.
            Unset for
             non-episodic layers.
        episodicKey:
          readOnly: true
          type: string
          description: >-
            Server-set on episodic layers: the caller-supplied episodic key the
            layer
             was created for. Unset for non-episodic layers.
    MemoryLayerInfo:
      type: object
      properties:
        entryCount:
          readOnly: true
          type: integer
          description: Number of entries currently in this layer.
          format: int32
        createdBy:
          $ref: '#/components/schemas/Profile'
        lastUsedAt:
          readOnly: true
          type: string
          description: >-
            Timestamp of the most recent objective that resolved against this
            layer.
             Useful for surfacing unused layers in the dashboard.
          format: date-time
        agent:
          readOnly: true
          allOf:
            - $ref: '#/components/schemas/ResourceMetadata'
          description: |-
            For episodic layers, the metadata of the agent the layer belongs to
             (resolved from MemoryLayerSpec.agent_id). Unset for non-episodic layers.
    GoogleProtobufAny:
      type: object
      properties:
        '@type':
          type: string
          description: The type of the serialized message.
      additionalProperties: true
      description: >-
        Contains an arbitrary serialized message along with a @type that
        describes the type of the serialized message.
    Profile:
      required:
        - metadata
        - spec
      type: object
      properties:
        metadata:
          $ref: '#/components/schemas/AccountResourceMetadata'
        spec:
          $ref: '#/components/schemas/ProfileSpec'
      description: |-
        A profile identifies a user or non-human principal (such as an API key)
         at the account level. Profiles are account-scoped and can be granted access
         to multiple workspaces.
    AccountResourceMetadata:
      required:
        - id
        - accountId
        - name
        - profileId
      type: object
      properties:
        id:
          readOnly: true
          type: string
          description: >-
            Unique identifier for the resource (prefixed ULID, e.g.,
            "apikey_01HXK...")
        accountId:
          readOnly: true
          example: account_01HXKD2E5NQM3T9AYWCFTJHJVF
          type: string
          description: >-
            Account this resource belongs to for multi-tenant isolation
            (prefixed ULID)
        name:
          type: string
          description: >-
            Human-readable name for the resource (e.g., "Customer Support
            Agent", "Email Tool")
             Required for resources that users interact with directly
        externalId:
          type: string
          description: >-
            External ID for the resource (e.g., a workflow ID from an external
            system)
        labels:
          type: object
          additionalProperties:
            type: string
          description: |-
            Key-value pairs for categorization and filtering. Values are 0-63
             alphanumeric characters with "-", "_", or "." allowed between; keys
             follow the same shape and additionally accept an optional DNS-subdomain
             prefix (e.g. "cadenya.com/") of at most 253 characters.
             Examples: {"environment": "production", "team": "platform", "version": "v2"}
        profileId:
          readOnly: true
          example: profile_01HXKD2E5NQM3T9AYWCFS0AP08
          type: string
        createdAt:
          readOnly: true
          type: string
          format: date-time
      description: >-
        AccountResourceMetadata is used to represent a resource that is
        associated to an account but not to a workspace.
    ProfileSpec:
      required:
        - type
      type: object
      properties:
        email:
          type: string
          description: >-
            Email address of the profile. Required and unique within an account
            for
             user profiles.
        name:
          type: string
          description: Display name (e.g., "Bobby Tables").
        type:
          enum:
            - PROFILE_TYPE_UNSPECIFIED
            - PROFILE_TYPE_USER
            - PROFILE_TYPE_API_KEY
            - PROFILE_TYPE_SYSTEM
          type: string
          description: >-
            Whether this profile represents a human user, an API key, or a
            system
             principal.
          format: enum
      description: Configuration for a profile.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT

````