When does Relay fail over?

Relay fails over on retryable provider failures such as timeouts, 5xx errors, and rate limiting. It follows the provider order defined in your policy and records each decision in the trace.

Do I need more than one provider?

Failover requires at least two providers. Most teams connect Twilio and Telnyx so Relay can route around incidents without changing application code.

Is Relay an SMS provider?

No. Relay orchestrates routing and proof on top of your provider contracts. You keep control of billing, compliance, and sender assets with your providers. Provider and carrier fees are billed by your providers.

How do I debug a failed message?

Open the message trace to see attempts, retries, receipts, and the recommended next steps. Relay normalizes provider errors and explains exactly why failover did or did not occur.

Solutions

SMS reliability you can prove.

Apian Labs Relay improves SMS delivery reliability for transactional notifications and incident updates. Define deterministic routing (primary → secondary with retries + cooldown), then inspect a trace timeline + receipts for every message. Relay is not an SMS provider - it orchestrates routing and proof on top of your provider contracts. Provider and carrier fees are billed by your providers.

Start free (test mode)View docs Pricing

Connect your Twilio and Telnyx accounts. Relay routes across them and records proof artifacts while your provider fees stay with your providers.

Reliability proof

accepted → attempt 1 (primary)

timeout → retry

failover → attempt 2 (secondary)

delivered → receipt + webhook

Solutions

Built for transactional notifications and incident updates

Relay is optimized for messages that must deliver under pressure and be explainable after the fact.

Transactional notifications

Password resets, login alerts, invoices, receipts
Deterministic retries + provider failover
Trace timelines to explain every failure

Critical incident communications

On-call notifications and user-facing incident updates
Fail over during provider incidents
Proof artifacts for post-incident review

Deterministic failover, not "smart routing"

Relay follows the provider order you define. When a retryable failure occurs (timeouts, 5xx, or rate limiting), Relay retries and then fails over to the next provider. Each decision is recorded in the trace so you can explain outcomes to your team and your customers.

Default behavior: primary → retries → secondary → primary cooldown.

Reliability Proof

Artifacts your team can use in real incidents

Relay generates proof artifacts for every message so engineers can debug failures and demonstrate reliability improvements. These artifacts also reduce support load because the system answers "what happened" and "what should I do next."

Trace timeline

Attempts, retries, failovers, and receipts in chronological order.

Failover event log

A structured record of why and when failover occurred.

Normalized error taxonomy

Provider errors mapped to consistent categories and actions.

Signed webhooks

Delivery + failover events you can trust and replay.

Export bundle

Copy/paste JSON for support and post-incident review.

How Relay works

From signup to production traffic with deterministic policies and proof artifacts.

Step 1

Create a workspace

Get API keys and start in test mode.

Step 2

Connect providers

Bring your Twilio/Telnyx credentials.

Step 3

Set routing policy

Primary → secondary → retries → cooldown.

Step 4

Send + trace

One endpoint + a timeline per message.

Fits your incident workflow

Webhooks

Stream delivery and failover events into your systems.

On-call tooling

Integrate failover observed events with tools like Slack or PagerDuty.

Status

Surface provider incidents and your own delivery health.

Simple pricing that scales with usage

Choose a plan with included relays, then use Relay Credits and auto top-up to prevent surprises.

View pricing

FAQ

Questions developers ask

Relay is an SMS-first reliability layer for transactional notifications and incident updates. It routes messages across your connected providers and generates trace timelines, receipts, and failover events for every message.

Start in test mode today

Connect your providers, send a test message, then inspect the trace timeline and webhooks.

Start free (test mode)View docs