Synthetic Canary SMS Injection

How to inject synthetic canary SMS events into production and staging webhook handlers for continuous uptime and latency monitoring.

canary_runner.py

Synthetics & Monitoring

import requests, time

def run_canary_check():
    start = time.time()
    res = requests.post("https://smsriver.com/api/v1/synthetic/sms/", headers={"Authorization": "Bearer sk_live"}, json={"to": "+12025550101", "body": "Canary heartbeat check"})
    duration_ms = (time.time() - start) * 1000
    assert res.status_code == 201
    print(f"Canary delivered in {duration_ms:.1f}ms")

crontab

REST API v1

*/5 * * * * python3 /opt/monitoring/canary_runner.py >> /var/log/canary.log 2>&1

Implementation Walkthrough

Schedule Canary Invocations

Set up a lightweight Cloudflare Worker Cron or Lambda timer to trigger canary SMS events every 5 minutes.

Verify Webhook Latency

Measure the round-trip latency from dispatch to webhook execution in your APM (New Relic or Datadog).

Alert on Pipeline Regressions

Trigger PagerDuty or Ops alerts if synthetic canary delivery fails or exceeds 2,000ms.

Supported MCP Agent Tools

list_countries

alias: sms_list_numbers

Discover supported countries, inventory counts, and carrier capabilities by source type.

get_number_capabilities

alias: sms_get_capabilities

Check line types, SMS capabilities, carrier limitations, and rental costs for a phone number or ISO country.

create_test_inbox

alias: sms_create_inbox

Create an isolated synthetic test inbox for deterministic webhook integration testing without real carriers.

generate_test_sms

aliases: sms_generate_sms, sms_create_synthetic_message

Inject zero-carrier-cost synthetic SMS inbound events directly into webhook endpoints for CI/CD test automation.

simulate_delivery_failure

alias: sms_simulate_failure

Simulate carrier drops, 10DLC rejections, DND blocks, and queue timeouts to verify retry handling.

inspect_webhook_events

alias: sms_inspect_webhooks

Query recorded test events, delivery status, latency, and raw carrier webhook payloads within plan retention.

replay_test_event

alias: sms_replay_event

Replay an existing test event to re-trigger local webhooks or reproduce failed integration test cases.

get_usage_summary

alias: sms_get_usage

Inspect current billing plan, monthly quota, consumed requests, and remaining units across REST and MCP.