> ## Documentation Index > Fetch the complete documentation index at: /docs/llms.txt > Use this file to discover all available pages before exploring further. # Retrieve a capacity forecast > Returns the group's dispatchable capacity over a future window of up to 90 days, derated by each device's limits, settings, consents and fulfillment history. ## OpenAPI ````yaml fleet-api/reference/flatpeak-api-spec-fleet.json GET /groups/{group_id}/capacity openapi: 3.0.3 info: description: >- The Flatpeak Fleet API. VPP operators use it to enroll, dispatch and settle OEM device fleets. ## Authentication Exchange your `account_id` and `secret_key` for a bearer token at `POST /auth/tokens` with basic auth. Send it as `Authorization: Bearer ` on every request. ## Base URL `https://fleet-api.flatpeak.com` ## Pagination Lists return `data`, `next_cursor` and `url`. Pass `next_cursor` as `cursor` until it is `null`. A cursor is opaque and bound to the endpoint and query parameters that issued it. ## Errors Every non-2xx response carries `object`, `type`, `code` and `message`. Branch on `code`. ## Money and energy Money is a decimal number paired with a `currency_code` (ISO 4217). Power is in kW and energy in kWh. Positive is import, negative is export. ## Live and test `live_mode` marks live or test data. version: 2027-01-01.busbar title: Flatpeak Fleet API termsOfService: https://flatpeak.com/legal contact: name: Technical Support email: support@flatpeak.com url: https://flatpeak.com/contact license: name: Apache 2.0 url: https://flatpeak.com/legal servers: - url: https://fleet-api.flatpeak.com security: - bearerAuth: [] tags: - name: Authentication description: >- Exchange your account credentials for a bearer token to authenticate API requests. - name: Connect description: >- Create and retrieve Connect sessions for onboarding customers through your own app. - name: OEMs description: List and retrieve the OEMs whose devices your fleet can reach. - name: Devices description: >- Retrieve, list and update the devices connected to your account, and read their consent history and shared settings. - name: Locations description: >- Read the location a device sits behind: its timezone, currency, metering and your devices there. - name: Dispatch description: Submit plans to devices on managed tariffs and read the dispatch timeline. - name: Telemetry description: Read device state, device meter records and location meter records. - name: Tariffs description: Create, retrieve, delete, and list tariffs. - name: Events description: Retrieve and list account events. - name: VPP Programs description: >- Define and manage VPP programs: the commercial terms devices enroll under, and their live state. - name: Groups description: >- Named collections of devices for bulk dispatch and aggregated reads. OEMs see them read-only as [groups](/energy-api/reference/groups/list) on the Energy API. - name: Zones description: >- Network areas resolved to devices by Flatpeak, for locational eligibility and grouping without handling addresses. - name: Exports description: >- Package settlement evidence, consent records and enrollment registers as downloadable files. - name: Rewards description: >- The reward ledger: entries accrue from delivery, you approve them, pay the customers and mark them paid. - name: VPP Enrollments description: Track and act on device enrollments across your programs. - name: VPP Events description: >- Commit market activations: create an event for a group, then read its state and its devices' results. externalDocs: description: Documentation url: https://docs.flatpeak.com paths: /groups/{group_id}/capacity: parameters: - schema: type: string name: group_id in: path required: true description: Flatpeak Group ID. get: tags: - Groups summary: Retrieve a capacity forecast description: >- Returns the group's dispatchable capacity over a future window of up to 90 days, derated by each device's limits, settings, consents and fulfillment history. operationId: get-capacity-forecast parameters: - name: start_time in: query required: true schema: type: string format: date-time example: '2026-08-13T17:00:00Z' description: Start of the forecast window, in UTC. - name: end_time in: query required: true schema: type: string format: date-time example: '2026-08-13T19:00:00Z' description: End of the forecast window, in UTC. - name: direction in: query required: true schema: type: string enum: - IMPORT - EXPORT example: EXPORT description: Dispatch direction to forecast capacity for. responses: '200': $ref: '#/components/responses/CapacityForecast' '400': $ref: '#/components/responses/400' '401': $ref: '#/components/responses/401' '403': $ref: '#/components/responses/403' '404': $ref: '#/components/responses/404' '422': $ref: '#/components/responses/422' '429': $ref: '#/components/responses/429' '500': $ref: '#/components/responses/500' '503': $ref: '#/components/responses/503' components: responses: '400': description: >- 400 Bad Request: the request was malformed or a required field is missing or invalid. content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: '401 Unauthorized: authentication credentials are missing or invalid.' content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: '403 Forbidden: you do not have permission to access this resource.' content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: '404 Not Found: the requested resource does not exist.' content: application/json: schema: $ref: '#/components/schemas/Error' '422': description: >- 422 Unprocessable Entity: the request is well-formed but cannot be processed, for example missing required data. content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: '429 Too Many Requests: the rate limit has been exceeded.' content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: >- 500 Internal Server Error: an unexpected error occurred. Safe to retry with backoff. content: application/json: schema: $ref: '#/components/schemas/Error' '503': description: >- 503 Service Unavailable: the service is temporarily down for maintenance. Retry after the indicated delay. content: application/json: schema: $ref: '#/components/schemas/Error' CapacityForecast: description: Capacity forecast response. content: application/json: schema: $ref: '#/components/schemas/CapacityForecast' example: object: capacity_forecast group_id: grp_2f6a9c1d8e3b5a7c4d0e9f1a direction: EXPORT data: - start_time: '2026-08-13T17:00:00Z' end_time: '2026-08-13T17:30:00Z' dispatchable_power_kw: 4820 dispatchable_energy_kwh: 2410 device_count: 1930 confidence: 0.83 - start_time: '2026-08-13T17:30:00Z' end_time: '2026-08-13T18:00:00Z' dispatchable_power_kw: 4610 dispatchable_energy_kwh: 2305 device_count: 1930 confidence: 0.82 schemas: CapacityForecast: title: CapacityForecast type: object description: >- Dispatchable capacity for a group over a future window, from each member's forecast, state, limits, settings and consents, derated by its fulfillment history. properties: object: type: string example: capacity_forecast description: Object type, `capacity_forecast`. enum: - capacity_forecast group_id: type: string description: Flatpeak Group ID the forecast covers. example: grp_2f6a9c1d8e3b5a7c4d0e9f1a direction: type: string enum: - IMPORT - EXPORT description: Dispatch direction the capacity applies to. example: EXPORT data: type: array items: type: object properties: start_time: type: string format: date-time description: Start of the window, in UTC. example: '2026-08-13T17:00:00Z' end_time: type: string format: date-time description: End of the window, in UTC. example: '2026-08-13T17:30:00Z' dispatchable_power_kw: type: number description: Average power the group can sustain across the window. example: 4820 dispatchable_energy_kwh: type: number example: 2410 description: Energy the group can shift across the window. device_count: type: integer description: Devices contributing to the window. example: 1930 confidence: type: number minimum: 0 maximum: 1 description: >- Confidence in the data, from 0 to 1, where 1 is fully accurate. example: 0.83 description: Dispatchable capacity, one entry per window. required: - object - group_id - direction - data Error: type: object description: Standard error envelope returned by every non-2xx response. required: - object - type - code - message properties: object: type: string enum: - error default: error description: Object type. type: type: string description: High-level error category. example: invalid_request code: type: string description: Machine-readable error code, safe to branch on. example: access_denied message: type: string description: Human-readable description of the error. example: The requested resource could not be found. context: type: string description: Optional originating context, for example `api.price_get`. example: api.price_get live_mode: type: boolean description: Whether the error occurred against live or test data. time_created: type: string format: date-time description: Time the error was generated (RFC 3339). example: '2026-01-01T00:00:00Z' securitySchemes: bearerAuth: type: http scheme: bearer description: >- Authenticate with the `bearer_token` obtained from the [authentication](/fleet-api/reference/authentication) endpoint. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.