Noxtr Specification Sheet

What is Noxtr?

Noxtr is a web-based Nostr client integrated into the ExtFW framework. It runs as a module within a self-hosted website, combining Nostr protocol access with server-side features like user accounts, Lightning address hosting, and NIP-05 identity verification.

It is designed as a single-page application with no external JavaScript frameworks — vanilla JS with a lightweight DOM helper (wquery).

Key Characteristics

NIP Support

Nostr Implementation Possibilities (NIPs) supported by Noxtr:

Event Kinds

Feature Overview

Client Comparison

An impartial comparison of Noxtr against established Nostr clients. Each client has different strengths — this table aims to be factual, not promotional.

General

Core NIP Support

Features

Known Limitations (not for long)

Areas where Noxtr is behind other clients:

• NIP-72/29 (Communities/Groups) — No moderated communities or relay-based group support.
• NIP-51 (Lists) — No relay-synced lists. Mute, bookmarks, and pinned channels are local (server DB only). Not interoperable with other clients.
• NIP-78 (App data) — No UI preference persistence on relays (kind 30078). Settings are local to the server DB only.
• NIP-35 (Torrents) — No torrent marketplace support (kinds 2003/2004). Natural fit with Noxtr’s P2P/Bitcoin focus.
• Multiple accounts — No instant account switcher. Changing accounts requires logout and re-login, but is possible.
• Outbox model — No per-user relay routing. All subscriptions go to the configured relay pool.
• No native app — Web only, but works on mobile via browser and supports “Add to Home Screen” for an app-like experience. No push notifications.

Distinctive Strengths

• Self-hosted identity — NIP-05 and Lightning addresses served from your own domain, auto-configured.
• Zero-dependency frontend — No npm, no build tools, no framework. Deploy by copying files.
• Internal zap transfers — Registered users can zap each other without Lightning network fees.
• NIP-28 channels — One of the few web clients with full public chat support (create, join, pin, invite links, delete own messages).
• NIP-23 articles — Long-form content integrated in the main feed with replaceable-event deduplication, Markdown rendering, and a dedicated composer with title/summary/image fields.
• Topic-based feed filtering — Subscribe to hashtags and filter your global feed without following specific users.
• AR mesh profile rendering — The only Nostr client that parses and renders AR collaboration/mesh profile broadcasts as visual cards.
• Dead domain detection — Automatically detects and gracefully handles dead image CDNs with 24h retry.
• NIP-46 with QR + persistence — Full Nostr Connect flow with QR code, localStorage persistence across sessions.
• Server-side Lightning — LNURL-pay endpoint with BTCPay integration and auto-generated server keypair for zap receipts.
• Built-in P2P Bitcoin trading (Mostro / NIP-69) — The only web Nostr client with native support for buying Bitcoin P2P via the Mostro protocol, with a step-by-step guided flow and per-order plain-language explanations — designed to be beginner-friendly.

₿itcoin P2P — Mostro

Noxtr includes native support for Mostro, a peer-to-peer Bitcoin exchange protocol built on top of Nostr. You can buy or sell Bitcoin directly with other people, with no inter/mediaries or custodians, paying by bank transfer, cash, or any other agreed method.

The P2P ₿ tab in the navigation bar gives you access to the live order book with all available offers.

Instances and protocol version

You can add and enable several Mostro instances (robots) in the chips bar of the P2P tab. The order book aggregates offers from all active instances; when creating an offer you choose which instance it is published to.

• Each chip shows a v1 (red) or v2 (green) label with the transport version the instance advertises (the protocol_version tag of its status event, kind 38385).
• Noxtr speaks the v2 transport exclusively (NIP-44 direct messages, kind 14). The v1 transport (gift wrap) is obsolete: offers from v1 instances are hidden from the order book and cannot be traded with.
• Clicking the v1/v2 label opens the full instance sheet: daemon version, order limits, fee, accepted fiat currencies, anti-abuse bond policy, Lightning node details, etc.

How to buy Bitcoin (step by step)

No prior Bitcoin experience needed. You only need a Lightning wallet on your phone (Phoenix, Breez, Zeus, Wallet of Satoshi…).

1. Open the P2P ₿ tab — You’ll see a list of sell offers with amount, currency, and payment method.
2. Choose an offer that suits you (amount, payment method) and press Buy.
3. Enter your Lightning Address (e.g. user@wallet.com) or a bolt11 invoice generated from your wallet — that is where you will receive the sats.
4. The robot takes over: it locks the seller’s Bitcoin and tells you how much to pay in fiat and how.
5. Send the money to the seller via the indicated method (bank transfer, cash, etc.) and press Fiat sent.
6. The seller confirms receipt of the fiat payment and presses Release sats.
7. Done! The sats arrive in your Lightning wallet. The trade appears as completed in its card.

If the seller’s wallet or the robot’s node cannot route the payment to your address, the trade card will show a field to enter an alternative Lightning address. Your sats are always safe with the robot.

How to sell Bitcoin

1. Press New order in the P2P ₿ tab and choose Sell BTC.
2. Configure the offer: fiat amount, currency, accepted payment method, and amount type (fixed or range).
3. Publish the order. It will appear in the order book for others to take.
4. When someone takes it, the robot sends you a hold invoice. Pay it from your Lightning wallet — the sats will be locked, not charged, until the trade finishes.
5. Give the buyer your payment details and wait to receive the fiat via the agreed method.
6. When the fiat arrives, press Release sats. The robot will send them to the buyer.

Import identity from Mostro Mobile

If you already use the Mostro Mobile app, you can import your identity into Noxtr without creating a new account:

1. On the Noxtr login screen, press 📲 Mostro Mobile.
2. Enter your 12-word seed phrase (the same phrase you use in Mostro Mobile).
3. Noxtr will derive your Nostr private key using the same standard as Mostro Mobile (BIP39 + BIP32, path m/44'/1237'/38383'/0/0).

This imports your identity (same key and therefore the same accumulated reputation). Trades started in Mostro Mobile are not recovered automatically: each interface manages its own trade sessions.

Reputation and ratings

After completing a trade you can rate the counterpart from 1 to 5 stars. Ratings received appear in your reputation card (⭐ average · number of trades). Mostro robots publish each user’s accumulated reputation alongside their order book entries.

By default Noxtr operates in full privacy mode (ephemeral keys per trade, no linkage between trades). To accumulate reputation, enable the ⭐ Reputation toggle: your trades become tied to your Nostr identity. Requires local nsec login (not possible with an extension or remote signer, because the identity proof requires signing outside the standard event format).

Disputes

If something goes wrong in a trade in the active or fiat-sent state (the counterpart does not respond, fails to send the money, denies receiving a confirmed payment…), you can open a dispute. Disputes are resolved by a human administrator of the Mostro robot.

1. Press Dispute on the trade card. The button appears next to the actions when the trade is in active or fiat-sent.
2. Confirm. Your client sends the dispute action to the robot.
3. The robot publishes the dispute and notifies the counterpart. Your trade moves to disputed with a dispute ID visible in the card.
4. Wait for an admin to take it. When that happens, you receive the admin-took-dispute action and a new direct chat panel with the admin appears below the trade card.
5. Resolve with the admin. This chat is independent of the chat with the counterpart and is encrypted with a shared key specifically derived between your trade key and the admin’s pubkey.
6. Admin verdict. The admin can release the sats to the buyer (admin-settle-dispute) or cancel the dispute returning them to the seller (admin-cancel-dispute). The trade closes automatically.

The Cancel dispute button (visible if you opened it and no admin is assigned yet) only hides it from your local list: the Mostro protocol has no way to withdraw a dispute, so on the robot it stays open until an admin resolves it.

If the counterpart asks for a cooperative cancellation on an active trade and you disagree, you can press Dispute instead of accepting the cancellation.

Your disputes are listed at /noxtr/disputes: dispute ID, public status (initiated / in-progress), initiator, assigned admin, and last update.

For administrators — Mostro P2P

On-chain P2P ₿itcoin — NostrEscrow

Besides the Lightning flow with Mostro, Noxtr supports on-chain P2P trades via NostrEscrow: funds are deposited into a 2-of-3 Taproot escrow address (buyer, seller and arbitrator), with no custodial robot.

• On-chain offers in the same order book (on-chain chip), with amount, payment method and proposed arbitrators.
• Taproot escrow: the seller deposits the BTC into the 2-of-3 address; buyer and seller cooperate to release, and the arbitrator only steps in on conflict.
• Arbitrators: public registry of arbitrators with terms and bond; the site operator acts as the default arbitrator.
• Your own keys: escrow keys are derived in your browser (BIP-86); the server never sees private keys.
• Encrypted chat between parties, disputes with arbitration and Monitor notifications at every step (taken, funding, fiat sent/received, payout, dispute).

Server Monitor — Notifications

The Monitor is a PHP process that runs in the background on the server and watches active Mostro trades even when no user has the web app open. It listens to Nostr relays continuously and acts whenever it receives relevant events.

For users — What does the Monitor do for you?

If the site administrator has the Monitor running, you will receive automatic alerts whenever something happens in your trades:

Each notification is sent once per trade and event type — no spam.

Link Telegram to receive alerts

1. While logged in, open the /telegram section of the web app.
2. Press the Link Telegram button: the two options below appear on that same screen, with a single-use code (expires after 10 minutes; if it expires, press the button again).
3. Option A — on mobile: tap the green “Open bot in Telegram” button shown right below the link button. The bot chat opens with the code already included; just press Start.
4. Option B — on desktop: copy the /start CODE command shown on that screen (Copy button), open Telegram, go to the site bot's chat and send it as a message.
5. The bot will confirm the link. From that moment on you will receive the alerts (new private messages, events on your trades...).

For administrators — Starting and stopping the Monitor

The Monitor is managed from the web admin panel (/noxtr/server_admin) via the Start / Stop / Status buttons, or directly from the server console:

php /path/index.php noxtr/server/action=monitor --verbose

To keep it running in the background:

nohup php /path/index.php noxtr/server/action=monitor > /var/log/monitor.log 2>&1 &

For administrators — Control commands via Nostr DM

The Monitor has its own Nostr identity. Authorized administrators can send it plain-text commands via DM from any Nostr client (including Noxtr). Its npub appears in the startup message and in the web panel.

For administrators — New order notifications

In addition to watching user trades, the Monitor notifies the administrator of every new order that appears in the Mostro order book (v2-transport instances only; obsolete v1 instances are ignored) and of every new on-chain offer. It can be toggled with the notify-new-offers on|off command.

• Nostr DM to the administrator’s npub with an order summary.
• Telegram with full details: ID, type (BUY/SELL), amount, payment method, and robot age.
• Email with the same information in HTML format.

To receive new-order notifications via Telegram, the administrator must have the bot linked and their Nostr pubkey added to admin_pubkeys in the Monitor configuration.

Technical Architecture

Backlog — Future Ideas and Improvements

Features queued without a defined date. The canonical source lives in _modules_/noxtr/BACKLOG.md within the repository.