Keep OTP verification available when a route fails
Flowstates supplies and operates a multi-vendor OTP delivery layer. Use your existing messaging providers, Flowstates routes or both, while your application keeps one send and one verify integration.
An accepted message is not a completed verification
A provider can accept an OTP request even when the code is later filtered, delayed, rejected or delivered after the user has abandoned the flow.
The outcome to protect is successful verification within the code’s lifetime — not API acceptance or a carrier delivery receipt.
OTP degradation is often local, not global
One country, operator, sender or route can fail while the provider’s headline status remains green.
OTP performance depends on the application request, vendor path, mobile operator, sender or template rules and end-to-end latency.
Aggregate delivery rates can hide a poor route in a commercially important market.
A backup vendor helps only when its routes, sender registrations and retry rules have been tested.
Failover must not create duplicate, stale or untraceable codes.
Why single-vendor and cold-backup designs fail
The weak point is usually the operating model, not the number of contracts.
A single-provider design leaves you exposed to:
- Provider or route degradation affecting all new OTP requests
- Limited visibility below the provider’s aggregate dashboard
- Engineering and support teams managing the incident manually
A second vendor is not resilience by itself
A backup path can still fail when:
- Sender IDs or templates are not registered on the backup route
- Provider statuses and error codes are not normalised
- Retry timing creates late or duplicate codes
- No one owns the routing decision and vendor escalation
Resilience requires a tested policy, shared observability and clear operational ownership.
The missing piece is a control loop. Detect, reroute, verify and recover.
Each OTP request needs to remain traceable while the delivery operation runs a continuous control loop.
Without that loop, route degradation is often discovered through resends, failed logins and support tickets.
Flowstates supplies and operates the OTP delivery layer
Use your current messaging vendors, Flowstates routes or a combination. Your application keeps a consistent OTP integration.
The service provides:
- One endpoint to send a code and one endpoint to verify it
- Configurable multi-vendor SMS cascade and approved fallback
- A priority path for time-sensitive verification traffic
- Attempt-level tracking together with managed routing and vendor escalation
Your identity or risk system still decides when SMS and fallback are appropriate. Flowstates runs the delivery operation around that policy.
See the OTP APIEach attempt stays linked to the original request and verification outcome.
What happens when a primary path degrades
Delivery control
- New requests move to an approved alternate path
- Retries follow configured timeout and attempt rules
- Each attempt remains linked to the original request
Operational response
- The affected route, market or operator is isolated
- The provider is engaged and the incident is tracked
- The primary path returns only after performance has recovered
The goal is not to promise zero failures. It is to reduce the blast radius and recovery time while keeping every attempt auditable.
OTP delivery moves from provider-dependent and manually recovered to controlled, observable and operated
Without an operated layer
- One application integration tied to one provider path
- Degradation discovered through user complaints and resends
- Engineering coordinates route changes and provider support
With Flowstates
- One API across approved vendors and routes
- Structured failover and request-level attempt history
- Flowstates owns routing changes and vendor escalation
Where this matters most
High-volume authentication
Signup and login flows where a small failure rate affects large numbers of users.
Multiple countries or operators
Customer bases where delivery performance varies significantly by market and mobile network.
Sensitive customer actions
Payments, payouts, account recovery and other time-critical verification flows.
Existing support or vendor overhead
Teams already managing resends, route incidents or multiple messaging providers.
Resilience is measured by completed verification
API acceptance is not the business outcome.
Measure whether the code arrived in time and whether the user completed the verification flow.
Then operate vendors, routes and fallback against that result.
Review the failure modes in your current OTP flow
Bring your main countries, providers, code lifetime, resend logic and verification data. We’ll map the single points of failure and a practical failover policy.