> ## Documentation Index > Fetch the complete documentation index at: https://docs.endstate.io/llms.txt > Use this file to discover all available pages before exploring further. # List units > Returns a cursor-paginated list of units, including each unit's collection and issuance status. Use `external_id` to filter to one caller-supplied identifier. ## OpenAPI ````yaml /openapi.json get /v1/units openapi: 3.1.0 info: title: Endstate API version: v1 description: Endstate developer API for chip verification and ownership workflows. servers: - url: https://api2.endstate.io description: Production security: [] paths: /v1/units: get: tags: - Units summary: List units description: >- Returns a cursor-paginated list of units, including each unit's collection and issuance status. Use `external_id` to filter to one caller-supplied identifier. parameters: - schema: type: integer minimum: 1 maximum: 100 default: 50 description: Maximum number of records to return. Defaults to 50; maximum 100. required: false name: limit in: query - schema: type: string minLength: 1 description: Opaque cursor from the previous page. required: false name: cursor in: query - schema: type: string minLength: 1 description: Filter to units with this external identifier. required: false name: external_id in: query responses: '200': description: A page of units. content: application/json: schema: $ref: '#/components/schemas/UnitsListResponse' example: units: - id: 33333333-3333-3333-3333-333333333333 external_id: unit-001 name: Example Unit attributes: custom_attribute: value created_at: '2026-05-16T12:00:00.000Z' redirect_url: null collection: id: 8e1a7f50-90ab-4cde-8012-3456789abcde name: Example Collection external_id: collection-001 contract: address: '0x1111111111111111111111111111111111111111' chain_id: 84532 status: active token: status: active serial: 5 chips: - chip_id: ABCDEF0123 is_test: false scan_count: 0 created_at: '2026-05-16T12:00:00.000Z' pagination: limit: 50 has_more: false next_cursor: null security: - ApiKeyBearer: [] components: schemas: UnitsListResponse: type: object properties: units: type: array items: $ref: '#/components/schemas/Unit' pagination: $ref: '#/components/schemas/CursorPagination' required: - units - pagination example: units: - id: 33333333-3333-3333-3333-333333333333 external_id: unit-001 name: Example Unit attributes: custom_attribute: value created_at: '2026-05-16T12:00:00.000Z' redirect_url: null collection: null chips: [] pagination: limit: 50 has_more: false next_cursor: null Unit: type: object properties: id: type: string format: uuid external_id: type: - string - 'null' name: type: - string - 'null' attributes: type: - object - 'null' additionalProperties: {} created_at: type: string format: date-time redirect_url: type: - string - 'null' format: uri description: >- Tap redirect URL for this unit; takes precedence over product/collection/org defaults. example: https://brand.example/p collection: allOf: - $ref: '#/components/schemas/CollectionMembership' - description: >- The unit's collection. Null only for units created before collections existed. chips: type: array items: $ref: '#/components/schemas/UnitChip' description: Chips paired to this unit. required: - id - external_id - name - attributes - created_at - redirect_url - collection - chips CursorPagination: type: object properties: limit: type: integer exclusiveMinimum: 0 description: Maximum number of records returned. example: 50 has_more: type: boolean description: Whether another page is available. Pass `next_cursor` to fetch it. example: false next_cursor: type: - string - 'null' description: Opaque cursor for the next page. Null when there is no next page. example: >- eyJjcmVhdGVkX2F0IjoiMjAyNi0wNS0xNlQxMjowMDowMC4wMDBaIiwiaWQiOiIzMzMzMzMzMy0zMzMzLTMzMzMtMzMzMy0zMzMzMzMzMzMzMzMifQ required: - limit - has_more - next_cursor CollectionMembership: type: - object - 'null' properties: id: type: string format: uuid name: type: - string - 'null' external_id: type: - string - 'null' contract: type: object properties: address: type: string description: Unique address identifying the collection. example: '0x1111111111111111111111111111111111111111' chain_id: type: integer example: 84532 status: type: string enum: - deploying - active - failed description: >- Collection lifecycle status. `deploying` while the collection is being provisioned; `active` once it is ready to use. example: active required: - address - chain_id - status token: $ref: '#/components/schemas/UnitToken' required: - id - name - external_id - contract - token description: >- The unit's collection and issuance status. Null only for units created before collections existed. UnitChip: type: object properties: chip_id: type: string description: Chip identifier from the tap URL. example: ABCDEF0123 is_test: type: boolean scan_count: type: integer minimum: 0 created_at: type: string format: date-time required: - chip_id - is_test - scan_count - created_at UnitToken: type: object properties: status: type: string enum: - pending - active description: >- Issuance state of this unit within the collection. `pending` until the unit is issued; `active` once issued. There is no failure status: a unit whose issuance cannot complete stays `pending` — if a unit remains `pending` well beyond a few minutes, stop polling and contact support. example: pending serial: type: - integer - 'null' description: >- Collection-scoped serial number. Assigned when the unit becomes `active`; null until then. example: 5 required: - status - serial securitySchemes: ApiKeyBearer: type: http scheme: bearer bearerFormat: end_sk description: >- Use `Authorization: Bearer end_sk_*` for partner API keys (e.g. `end_sk_AbCd_example_api_key`). ````