Free, open-source software for developers and public-interest organisations that build the menus people open by dialling a code. You run it yourself, so you own the service and its data.
See it on a phoneAn early version: it works, but it is not ready for real users yet. Free and open source.
Works with
Why it matters
If you have ever dialled a code to check your airtime balance, you have used USSD. A text menu appears and you reply with a number. It works on every phone, with no internet.
In Sub-Saharan Africa, 60% of mobile internet subscribers still use a basic or 3G phone (GSMA, 2025). Building a menu is hard, so mostly banks and phone companies have one. OpenUSSD is for everyone else.
Patients confirm or change a clinic visit by pressing a number. No app, no smartphone, no data bundle.
Chama members check their savings and the next meeting from any phone, without calling the treasurer.
This one works today: the demo reads posts from Mastodon, an open social network, on a basic phone.
Runs on your own server, so you own the service and its data. Change providers without rewriting, and later connect to a network directly.
The clinic and chama screens are examples. The community news screen is real output from the demo.
A real session
Real screens from the current version, step by step.
Handset screen: OpenUSSD Fediverse
1. Public timeline
2. About
0. QuitHandset screen: Latest posts
1. Kiambu Farmers Coop (now)
2. Shule ya Msingi (3m)
3. Ward Office (9m)
0. QuitHandset screen: Shule ya Msingi (1/2)
Habari za asubuhi! Mkutano wa
wazazi utafanyika Jumamosi saa
nne asubuhi katika ukumbi wa
shule. Tafadhali fika mapema
1. Next 0. BackHandset screen: Shule ya Msingi (2/2)
🙏
2. Prev 0. BackPlanned, not built
SMS hand-over
Today OpenUSSD does USSD menus only. SMS is planned for a later release.
Screens from the test phone that comes with OpenUSSD, using sample posts.
Status
Version 0.1 is an early version. Here is what works, what is missing and what to watch out for.
The full plan is in the roadmap. Want to help? Read the contributing guide.
How it works
1. Dial
Any phone
*384*1234#
through the phone company
2. OpenUSSD
OpenUSSD
3. Your app
Your app
any language
Go toolkit today, TypeScript planned
A phone dials *384*1234#
Any phone with a SIM card. The phone company sends each step to OpenUSSD in its own format.
OpenUSSD translates it
It turns every format into one, remembers where the person is, and sends a signed message to the right app.
Your app answers with the next screen
Your app can use any programming language. A Go toolkit keeps every screen short enough; TypeScript is planned.
For developers
You need Docker and Go installed. A test phone runs in your terminal, so you need no account with a phone company.
git clone https://github.com/davidrukahu/openussd
cd openussd
export FEDIVERSE_WEBHOOK_SECRET=$(openssl rand -hex 32)
docker compose up --build
# in a second terminal
go run ./cmd/ussdsim -shortcode '*384*1234#'1Clone the repository and set a webhook secret.
2Start the gateway and the Fediverse tenant with Docker Compose.
3Dial the demo shortcode from cmd/ussdsim in a second terminal.
To use a phone in your browser instead, connect a free Africa's Talking test account. See getting USSD access in practice.
The menu you get when you dial a short code, for example to check your airtime balance or buy a data bundle. You reply with a number. It works on every phone, with no app and no internet.
Developers and public-interest organisations, such as health, education, farming and local government teams, that run USSD services and want to own them. If you need one simple menu in one country, a provider on its own may be enough.
You still use one. A provider connects you to the phone networks, but you build the menu yourself, in that provider's own format. OpenUSSD does the hard parts once, such as remembering each step, fitting every screen and checking where requests come from. It also lets you change or add providers without rewriting your menu. Today it supports Africa's Talking; more providers are planned.
You, your provider and the phone network. OpenUSSD runs on your own server, and there is no OpenUSSD company or cloud in between.
Not yet. Direct connections over SMPP, a protocol many networks offer, are planned. They remove the provider in the middle, but need an agreement with the network.
Not to build and test. To go live, you need an agreement with Africa's Talking or a phone company. Here is what is possible today.
Africa's Talking today, which reaches Kenya, Uganda, Nigeria, Rwanda, Tanzania and Malawi. MTN and others are planned.
Not yet. It is an early version, and parts will change before version 1.0. See known limitations.
The software is free (AGPL-3.0). You pay only for hosting, and for each session Africa's Talking or a phone company charges.
It is unfunded so far. The roadmap shows what funding would pay for.
Open standards
Published standards and a documented format, so anyone can build on it.
GSM 03.38
3GPP TS 23.038
The standard alphabet for phone text. A screen holds 182 of its letters, or 70 when other characters appear.
USSD
3GPP TS 24.090
Unstructured Supplementary Service Data: the menu session a *123# code opens.
ActivityPub
W3C Recommendation
The standard behind Mastodon and the open social web. The demo reads posts through Mastodon.
HMAC-SHA256
RFC 2104
A standard way to sign messages, so an app can check that a message really came from OpenUSSD.
Redis
optional
Optional. Shares the conversation memory when you run OpenUSSD on more than one server.
Free and open source. Developers can try it in minutes, and organisations can get in touch on GitHub.
Visit the project on GitHub