> ## Documentation Index > Fetch the complete documentation index at: https://developers.telluspowergroup.com/llms.txt > Use this file to discover all available pages before exploring further. # Heartbeat > Periodic (e.g., every 30 seconds) report from the charger of online status. The response may include pending commands queued for the device. **Related:** for diagnosing connectivity issues such as stale heartbeat or reconnect storms, see the [Diagnostic Runbooks](https://developers.telluspowergroup.com/diagnostics/runbooks). ## OpenAPI ````yaml /api-reference/openapi.json post /device/heartbeat openapi: 3.1.0 info: title: Tellus Open Platform API version: 1.3.0 summary: Charger-platform integration API for CPMS, EMS, aggregators, and chargers. description: > The Tellus Open Platform API enables Charging Point Management Systems (CPMS), Energy Management Systems (EMS), aggregators and chargers themselves to integrate with the Tellus charging-platform infrastructure. The API is divided into three logical surfaces: - **Operator-side API** (`/v1/operator/...`) — used by CPMS, EMS, and aggregators to query the fleet, retrieve charging records, control chargers, schedule charging, issue load-flexibility commands, and subscribe to a real-time telemetry WebSocket. - **Charger-side API** (`/v1/device/...`) — used by chargers themselves for registration, heartbeat, telemetry, event reporting, charging-record upload, command fetching (long-polling), command-status reporting, and firmware-upgrade status. - **Operator-to-operator interop (legacy)** — an older roaming-style interface (PascalCase, PUT-based) used for data exchange between operator platforms, modelled after China's national charging-interop standard. Most modern partners should integrate via the Operator-side API instead. All requests use HTTPS (TLS 1.2 or higher). Plain HTTP is not supported. All bodies are `application/json`. Timestamps are ISO 8601 UTC. Energy is in kWh, power in kW, current in A, voltage in V, temperature in °C, and SOC is an integer percentage 0–100. Optional request signing using HMAC-SHA256 is supported for high-security operations (see §2.2.4 of the v1.3 specification). contact: name: Tellus Power — Platform Team url: https://www.telluspowergroup.com license: name: Proprietary — Tellus Power Group servers: - url: https://api.telluspower.example.com/v1 description: > Production (HOSTNAME PENDING). The v1.3 specification uses `api.chargingplatform.com` as a placeholder; the real production hostname has not yet been confirmed by the developer team. - url: https://api-test.telluspower.example.com/v1 description: | Test / Sandbox (HOSTNAME PENDING). To be confirmed by the developer team. security: [] tags: - name: Operator — Authentication description: OAuth2 client-credentials grant for CPMS / EMS / Aggregator integrations. - name: Operator — Sites & Devices description: >- Read-only resource queries — sites accessible to the authenticated client, and per-device detail with connector states. - name: Operator — Remote Control description: >- Initiate charging, stop charging, V2G discharge, and set charging schedules remotely. - name: Operator — Charging Records description: Historical session data (CDR — Charging Detail Records). - name: Operator — Energy & Flexibility description: >- Aggregated energy time-series and load-flexibility / demand-response control. - name: Operator — Commands description: Track execution of issued commands. - name: Operator — Telemetry Stream (WebSocket) description: >- Real-time telemetry subscription via WebSocket. Documented here for reference; the connection is established outside the OpenAPI request/response model. - name: Charger — Provisioning description: First-time device registration and access-token issuance. - name: Charger — Reporting description: Heartbeat, real-time telemetry, event reporting, charging-record upload. - name: Charger — Commands description: Long-polling for pending commands and reporting their execution status. - name: Charger — Firmware description: Firmware upgrade status reporting. - name: Operator-to-operator (legacy interop) description: | Older roaming-style interface (PascalCase fields, PUT methods) used for data exchange between operator platforms. Modern partners should normally integrate via the Operator-side API instead. externalDocs: description: >- Tellus Power developer documentation — guides, diagnostics, runbooks, and proposed API extensions url: https://developers.telluspowergroup.com paths: /device/heartbeat: post: tags: - Charger — Reporting summary: Heartbeat description: > Periodic (e.g., every 30 seconds) report from the charger of online status. The response may include pending commands queued for the device. **Related:** for diagnosing connectivity issues such as stale heartbeat or reconnect storms, see the [Diagnostic Runbooks](https://developers.telluspowergroup.com/diagnostics/runbooks). requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/HeartbeatRequest' example: timestamp: '2025-03-15T10:30:00Z' status: online fault_code: 0 responses: '200': description: Heartbeat acknowledged. Pending commands may be returned. content: application/json: schema: allOf: - $ref: '#/components/schemas/ApiEnvelope' properties: data: type: object properties: commands: type: array items: $ref: '#/components/schemas/PendingCommand' security: - deviceBearer: [] externalDocs: description: >- Connectivity diagnostic runbook for stale-heartbeat and reconnect-storm scenarios url: https://developers.telluspowergroup.com/diagnostics/runbooks components: schemas: HeartbeatRequest: type: object required: - timestamp - status - fault_code properties: timestamp: type: string format: date-time status: type: string enum: - online - offline - fault fault_code: type: integer description: 0 = no fault; otherwise platform-defined code. ApiEnvelope: type: object description: | Standard response envelope. `code` is `0` on success and a non-zero application code on error (see Error Codes — §14). required: - code - message properties: code: type: integer description: 0 = success; otherwise an error code per the Error Codes section. message: type: string description: Human-readable description. data: description: Endpoint-specific payload. PendingCommand: type: object required: - command_id - command - params properties: command_id: type: string command: type: string description: >- Command type — e.g., `start_charging`, `stop_charging`, `set_power_limit`, `set_schedule`, `firmware_upgrade`, `discharge`. params: type: object description: Command-specific parameters. expiry: type: string format: date-time securitySchemes: deviceBearer: type: http scheme: bearer bearerFormat: JWT description: | Charger-side bearer token. Obtained by exchanging `device_id` and `device_secret` (issued at registration) at `/v1/device/token`. Valid for 24 hours. ````