What Is Mantra? Exonumia Africa's E2EE Translation Tool

Exonumia Africa, the South African non‑profit that's spent years translating Bitcoin literature into native African languages, launched Mantra on September 9, 2026 — an end‑to‑end encrypted, decentralized tool built specifically to manage that translation work. The team describes it simply: "a press a group holds in common."

What is Mantra?

Mantra is a group messaging and translation app where a group's private conversation, shared library, and published translations are all held under a key that no single member controls.

There's no account to recover and no company or server that can read what the group says — identity is just a key the user owns. The app does four things, by design, and nothing more:

Speak: end‑to‑end encrypted group conversation. Relays carry only ciphertext; they can't read it, and neither can Exonumia.

Translate: a work is broken into chapters, chapters into chunks, and a group renders each chunk into the dialects its members speak.

Sign: the group agrees on one signing key through a setup ceremony, and members each hold a share of it. Nothing publishes until enough shares sign off.

Hold: a twelve‑word recovery phrase restores both identity and wallet. Payments settle over the Lightning Network, to keys held on the user's own device.

Why did Exonumia Africa build it?

Exonumia Africa has translated Bitcoin literature — including the whitepaper, early Satoshi emails, and books such as Nik Bhatia's Layered Money, per earlier coverage of the project — since Kgothatso Ngako started the project in 2019; the nonprofit entity behind it was formally registered in 2021.

The team says it's been managing translations across more than 21 languages, with support at various points from organizations including BitMEX, the Human Rights Foundation, Galoy, and Bitcoin Beach. Coordinating translators, reviewers, and editors across that many languages, in the open, is exactly the kind of workflow existing tools weren't built for.

For the fuller origin story, the University of Pretoria profiled Ngako's path from alumnus to Bitcoin‑translation founder.

Ngako is also the builder behind Machankura, a USSD‑based Bitcoin access app aimed at users across Africa who don't need a smartphone to use Lightning — detailed in a 2024 CoinDesk interview. Mantra comes from the same circle of builders.

Per the team's own announcement, Mantra started as an internal tool "many moons ago," before Exonumia realized their translation process was basically a group chat: proposing a translation, discussing edits, and signing off.

Ngako has since put a number on that timeline himself: in a separate post, he says he's "been trying to build this thing for the past 5 years," crediting BIP32, Nostr, FROST, ChillDKG, Marmot, MLS, and Bitcoin as the technologies that made it possible. The project's repository backs that up — its initial commit is dated five years ago.

How does approval and signing work?

Mantra's most distinct feature is cryptographic group sign‑off. When a group forms in Mantra, its members run a key ceremony and agree on a signing threshold — for example, requiring 3 of 5 members to approve before anything is published. This uses FROST, a threshold signature scheme, so publishing a translated work requires real, verifiable agreement from the group rather than trusting one editor or admin.

How do members know the group key's entropy wasn't tilted toward one participant during setup? Exonumia says Mantra experimentally runs ChillDKG over NIP‑17 so every participant can verify the key‑generation ceremony itself — Blockstream has a good plain‑language explainer on how ChillDKG works if you want the full mechanics.

Once that's done, the signing key becomes the group's identifier, and translators propose work while admins approve it from wherever they are. Approvals stay verifiable against the group ID today; the team says staying verifiable as the admin roster itself changes over time is coming next.

Groups can also split into subgroups — a regional desk or a specific‑language team, for instance — each running its own key ceremony and holding its own signing shares independently. The parent group can't sign on a subgroup's behalf; instead, it issues a signed "birth certificate" establishing the subgroup as its child, which anyone can verify later. Learn more about it in their announcement thread.

What's the underlying tech stack?

Mantra runs on Nostr, a decentralized relay‑based protocol, rather than Exonumia's own servers. Messages are sent to several relays at once, and a group reads from whichever relay answers — so no single relay is privileged, none can read the messages it carries, and users can point Mantra at any relay they choose, including one they run themselves.

For encryption, Mantra uses MLS (Messaging Layer Security), the IETF's standard for secure group messaging, implemented through the Marmot protocol, with NIP‑17 handling private, gift‑wrapped one‑to‑one messages within the same encrypted frame. Sender identity is proven by a member's position in the group's cryptographic key tree rather than by anything written in the message itself.

Marmot's own docs walk through the full layering — relay‑stored ciphertext, the MLS application message, and the plaintext only the group can read.

Is Mantra available now?

Mantra is in alpha. It's built for Android, iOS, and desktop, but general sign‑in isn't open yet, right now:

Anyone can test it by downloading the APK directly.
TestFlight and Google Play open testing unlock by sending sats to Exonumia's published Bitcoin address: bc1qsj003mfyylaca7jg5zndel2gvmja47gfhkpke9.
The full source code and protocol documentation are public at code.sigidli.com/mantra/mantra‑kmp.

This is alpha software, and the team is explicit about it: the default relay may drop messages, any update can wipe the local database, and general sign‑in isn't open. Their own advice is to wait for beta if you need it for real work.

Frequently asked questions

What is Mantra?

Mantra is an end‑to‑end encrypted, decentralized group messaging and translation tool built by Exonumia Africa, where groups translate written work together and cryptographically sign off on the final result before publishing.

Who built Mantra?

Exonumia Africa, a South African non‑profit whose Bitcoin‑translation work began in 2019 under founder Kgothatso Ngako (the nonprofit entity itself was registered in 2021), built Mantra to manage its translation workflow — which the team says spans more than 21 languages.

What protocols does Mantra use?

Mantra runs on Nostr relays for message delivery, MLS (Messaging Layer Security) via the Marmot protocol for group encryption, NIP‑17 for private one‑to‑one messages, and FROST threshold signatures for group sign‑off on published work.

Is Mantra available to download?

Mantra is in alpha. The APK is available to download directly for testing, and TestFlight/Google Play open testing unlock by sending sats to Exonumia's listed Bitcoin address.

What does Mantra's group signing feature do?

Each group sets its own approval threshold — for example, 3 of 5 members — and a translated chunk only publishes once that many members have cryptographically signed off, using the FROST threshold signature scheme.

What is ChillDKG in Mantra?

ChillDKG is the distributed key‑generation ceremony Mantra runs over NIP‑17 when a group first forms. Every participant can verify the resulting shared signing key wasn't skewed toward any one member.

Is Mantra related to MANTRA Chain or other projects called "Mantra"?

No. Exonumia Africa's Mantra (mantra.press) is unrelated to MANTRA Chain (mantrachain.io), a separate blockchain project, or to an unrelated AI coding tool at mantra.gonewx.com.