23ms median · in‑region
Delayed webhooks, delivered.
Schedule HTTP callbacks in seconds to days. We handle the timing.
Features
Human-readable delays
Write "30s" or "7d", not Unix timestamps. Schedule seconds to days ahead.
Signed deliveries
Every webhook signed. Verify it came from Solenoid, not an attacker.
Guaranteed delivery
Failed? We retry with backoff. You don't have to build retry logic.
Your payload, your headers
Send exactly what your endpoint expects. No reformatting.
Try It
Schedule Webhooks
Timeline
No webhooks scheduled. Click a button above to start.
API Example
Complete Workflow
# 1. Setup
export SOLENOID_KEY="sm_your_api_key_here"
# 2. Schedule a webhook
curl -X POST "https://api.solenoid.systems/v1/relay" \
-H "Authorization: Bearer $SOLENOID_KEY" \
-H "Content-Type: application/json" \
-d '{
"target_url": "https://your-app.com/webhooks",
"method": "POST",
"delay": "30s",
"payload": {"event": "payment_reminder"}
}'
# Expected response:
# {"id":"rel_abc123","status":"scheduled","deliver_at":1234567890,"target_url":"https://your-app.com/webhooks"}
# 3. Check webhook status
curl "https://api.solenoid.systems/v1/relay/rel_abc123" \
-H "Authorization: Bearer $SOLENOID_KEY"
# Expected: {"id":"rel_abc123","status":"delivered","delivered_at":1234567920}Use Cases
Payment Reminders
Send follow-up notifications after a configurable delay.
Retry Orchestration
Schedule retry attempts with increasing backoff intervals.
Drip Campaigns
Trigger onboarding emails at day 1, 3, and 7 after signup.
Scheduled Cleanup
Fire cleanup webhooks after temporary resources expire.
Comparison
| Feature | Solenoid Relay | AWS SQS + Lambda | Quirrel |
|---|---|---|---|
| Delay Range | Seconds to days | 0-15min max | Seconds to years |
| Retries | Auto exponential | DLQ manual | Configurable |
| Signatures | HMAC built-in | DIY | None |
| Infrastructure | Serverless | Managed | Self-hosted |
| Pricing | $0.50/1K webhooks | $0.40/1M + Lambda | Free (OSS) |
| Best for: | Serverless delayed callbacks | AWS ecosystem integration | Full control, self-managed |
Pricing as of Feb 2026 for AWS us-east-1