Retries

Hot supports automatic retries for:

• Event handlers (meta {on-event: "...", retry: ...})
• Scheduled functions (meta {schedule: "...", retry: ...})

Retries are configured with the retry metadata field.

retry does not apply to synchronous request/response surfaces like MCP tool calls and webhook invocations.

Retry Metadata

The retry field supports two forms.

Simple form:

retry: 3

Full form:

retry: {
  attempts: 5,
  delay: 5000,
  backoff: "exponential",
  max_delay: 120000,
  jitter: true
}

Backoff formulas:

• "fixed": delay
• "exponential": delay * 2^attempt
• "linear": delay * (attempt + 1)

How Retries Execute

When a retryable run fails:

1. Hot reads retry config from function metadata.
2. If attempts remain, the run is updated to pending_retry.
3. A new run is scheduled at next_retry_at.
4. The retry run is linked to the original via origin_run_id.
5. Retries stop on success or when attempts are exhausted.

In Hot App, retries are shown with retry badges (for example ↻1, ↻2) and linked run history.

Limits and Clamping

Retry values are clamped to configured platform limits:

Values below minimum delay are raised, and values above configured limits are capped.