Sigfox Cloud Callback Workbench
Trace how Sigfox Cloud turns small device uplinks into HTTP callbacks for an application platform
Trace a Sigfox message from radio burst to application callback.
Sigfox devices do not open HTTP connections. They send tiny radio uplinks; base stations forward copies to Sigfox Cloud, which triggers the callback configured for that device type. Use presets to test delivery, duplicates, timeouts, metadata delay, and downlink handoff.
Workbench Controls
Start with a preset, then adjust callback type, endpoint behavior, and payload size.
Device Type Callback Pipeline
A DATA UPLINK callback fires when Sigfox Cloud receives the first frame for the device message.
Callback Body Preview
Delivery Decision
No callback has been sent yet.
Small uplink
Device wakes, transmits a compact payload, then can go back to sleep.Base station copies
One or more stations hear the same message and backhaul it to Sigfox Cloud.Cloud routing
Cloud applies device type behavior, variables, optional metadata, and deduplication.HTTP callback
Your endpoint receives the event and must respond quickly with an appropriate status.Application action
The platform stores the event, triggers alerts, or returns an 8-byte BIDIR downlink.Plain-English Model
Think of the device as mailing a tiny postcard. The network operator carries it, and your server receives a webhook copy.
What Moves
The orange token is one device message. It moves from radio reception to cloud routing, then to the callback endpoint.
What To Notice
Callback type changes timing, fields, and whether a downlink answer is expected. It does not make the device an IP client.
Beginner Trap
Do not send JSON from the device. Encode sensor values into a few bytes, then decode them in the cloud or application.
Callback Result
The endpoint has not been called yet.
Payload Budget
Use binary packing to stay inside the 12-byte uplink limit.
Integration Guardrail
A callback is event delivery. Use REST API v2 for fleet administration and message queries.
Callback Quick Reference
| Type | When It Fires | Use It For |
|---|---|---|
DATA UPLINK |
First frame for a received uplink message. | Fast sensor data delivery to an HTTP endpoint. |
BIDIR |
Uplink that asks the platform for a downlink answer. | Rare configuration or command responses. |
DATA ADVANCED |
After metadata is computed across receiving stations. | Lower urgency integrations that need richer network/geolocation metadata. |
SERVICE / ERROR / EVENT |
Device behavior, communication status, or cloud entity events. | Operations and lifecycle monitoring, not the main data path. |
Uplink Variables
| Variable | Meaning | Caveat |
|---|---|---|
{time} |
Unix epoch time in seconds. | Use server-side timezone handling. |
{device} |
Hexadecimal device identifier. | Validate against your registry before trusting the event. |
{data} |
Hexadecimal device payload. | Decode bytes according to your device type grammar or app schema. |
{rssi}, {station} |
Reception metadata for a base station copy. | Available only with the relevant network metadata option. |
Retry And Acknowledgement
The endpoint should answer within 10 seconds. Timeout or error responses trigger retries after 1, 2, and 4 minutes.
How to design the endpoint
- Return a 2xx response quickly, then process asynchronously.
- Deduplicate by device plus sequence number because retries can replay the same event.
- Log Sigfox-specific error/status codes separately from HTTP failures.
Payload And Downlink
Use compact binary uplinks. A bidirectional exchange is device-initiated and the downlink payload is limited to 8 bytes.
Why the payload is so small
- Sigfox is optimized for low-power, low-throughput sensors.
- Send values, flags, and indexes, not verbose strings.
- Keep rare configuration changes in downlink; keep routine telemetry in uplink.
Security Checklist
Treat callbacks like webhooks from an external service, then validate before writing to your application state.
Minimum checks
- Use HTTPS with a public CA certificate; self-signed certificates are not suitable for Sigfox Cloud callbacks.
- Allow-list the current Sigfox Cloud callback IP range from the support documentation.
- Validate device ID, sequence number, and payload length before accepting data.
Guided Task 1
- Select Duplicate receive.
- Step until the cloud stage is active.
- Explain why three base station copies should still produce one application event.
Guided Task 2
- Select Endpoint timeout.
- Step through the retry ladder.
- Identify the field pair your application should use to deduplicate retry attempts.
Guided Task 3
- Select Oversized design.
- Reduce the payload slider until the budget turns healthy.
- Decide which values must be packed into bits or moved out of the uplink.
Guided Task 4
- Select BIDIR downlink.
- Step to the application stage.
- Explain why the device must request the downlink before the platform can answer.