Provider to hosted application
The telecom provider sends each approved USSD request to the hosted session application and receives the next screen in return.
Beginner guide · Updated 20 July 2026
How programmable USSD actually works.
The numbered screen on the phone is only the visible part. Behind it is a session-based application that interprets each reply, follows rules and can connect approved business services.
The complete system
The phone, provider and application each do a different job.
A useful USSD service is not stored inside the caller’s phone. The mobile network and provider carry the live session; the hosted application returns each approved response.
Hubtel’s public terms also describe USSD as a live session connected to a customer application through HTTP. Read Hubtel’s public USSD terms.
- 01
The caller dials a shortcode.
The network opens a session and sends the approved request through the provider connection.
- 02
The application returns the first screen.
It may show a welcome message, numbered choices or a request for typed information.
- 03
The caller’s reply changes the state.
The application validates the answer, remembers where the caller is and follows the relevant rule.
- 04
The session continues or ends clearly.
The application returns another screen or a final response. Later provider callbacks may still update the business record.
Three meanings of integration
“USSD integration” is not one connection.
A production service usually has a provider connection, a business-data connection and one or more result-driven services.
Application to business records
The flow can look up or update the supported customer, booking, order or account record needed for the next decision.
Payments, SMS and fulfilment
Approved providers perform their part and return a result. The software records that result before it confirms or fulfils the business action.
Worked example
A school-fee journey is more than a menu.
Studio safely simulates the conversation. A reviewed live implementation would need approved records and provider connections behind it.
- 01
Identify the student
The caller enters a student reference in the USSD session.
- 02
Find the relevant record
A live implementation checks the supported school record and returns the useful account information.
- 03
Choose what to do
The caller can review the result and follow an approved payment or support path.
- 04
Wait for provider confirmation
A payment request is not treated as paid until the payment provider reports a verified result.
- 05
Record and confirm
The software updates the correct account and may ask an approved SMS provider to send a receipt or status message.
What Iderwell provides
One product, different availability.
The public builder works today. Live telecom work remains a separately reviewed service with provider-controlled prerequisites.
Visual USSD builder
Arrange menus, questions, typed answers, simulated payment and SMS steps, and clear endings without writing code.
Runs in the public browser alpha.Simulator, versions and sharing
Test every path, save the flow, export its definition and send a fixed read-only simulation to a teammate or client.
A verified free account is required for saved and shared work.Shared production runtime
The planned production layer would answer approved provider sessions after the required security, reliability and provider gates pass.
Not available for a new shared-Studio go-live order today.Shared production integrations
Design-partner scoping can define approved payment, SMS and business-record connections required by a future production service.
Prototype planning is available; the shared live connection is not yet available.Shared operations portal
The planned production platform would provide protected views for sessions, business records, provider states and exceptions.
The shared Studio operations portal is not built or available today.KYC, shortcode and network access
For the current reviewed Ghana path, Hubtel decides merchant approval, shortcode allocation, network rules and provider charges. Other provider paths are future.
Iderwell cannot guarantee provider approval.Useful language
Technical terms, translated.
These terms should help you understand a provider discussion. You do not need to memorise them before using Studio.
- USSD application
- The server-side service that decides which short screen appears, accepts the caller’s reply and chooses what happens next.
- Flow
- The connected screens, questions, rules and endings that make up the customer journey.
- Session
- One live conversation between a caller and the USSD application. The application keeps enough context to understand each next reply.
- Service interaction URL
- The agreed public address a provider uses to send an approved USSD interaction to the hosted application.
- Fulfilment or callback URL
- An agreed address used for a later provider result, such as the outcome of a payment or another requested service.
- Shortcode
- The dialable code assigned or connected by an authorised provider. A builder or browser simulator does not allocate it.
Common questions
Keep the category clear.
The simple explanation and the technical definition can coexist.
Is programmable USSD just a list of numbered menus?
No. The numbered screen is the interface. A programmable application can remember the current session, validate input, branch on rules, use supported business records and respond to provider results.
Does a USSD application run on the phone?
The customer uses the phone and mobile network, but the application logic normally runs on a server connected through an authorised USSD provider.
Can I test a programmable flow before obtaining a shortcode?
Yes. Iderwell USSD Studio can build and simulate supported flows in a browser. That test does not create a live network service or contact a provider.
Can Iderwell connect every API or provider today?
No. The public alpha does not provide arbitrary HTTP or code nodes, automatic provider onboarding or universal live deployment. Supported live connections are reviewed and agreed separately.
Start without a shortcode
Build it yourself or bring the outcome to Iderwell.
A browser test makes scoping more precise, but you do not need one before applying as a founding design partner.