Formerly Claude S40. The project was called Claude S40 up to phone app 0.10.x / server 0.7.x, while it only talked to Claude. Since it also speaks to OpenAI, Gemini and Grok it is called AIKON (Nokia spelled backwards). The repository moved from emir/claude-s40 to emir/AIKON (GitHub redirects the old address); the Java package and server names keep the old name.

Today's AI on a 2007 Nokia. AIKON is an AI chat client for Nokia Series 40 and Symbian S60 phones (Java ME, CLDC 1.1 / MIDP 2.0), plus the small Go server it talks to. Pick a model per chat (Claude, OpenAI, Gemini or Grok), type on the keypad, get the answer on a 240x320 screen: with today's news, weather and exchange rates from web search, long answers you can page through, and a UI in Turkish, English, Spanish, Portuguese, French, German, Russian or Indonesian. Tested on the Nokia 6300 (S40) and the Nokia E63 (S60 QWERTY).

Video (still as Claude S40): on a Nokia 6300, on X

On the phone

• Pick the model per chat: first the provider (Claude, OpenAI, Gemini, Grok), then one of the models the server offers; switch in the middle of a chat with Options > Model. Every reply is labelled with its model.
• Chat: your messages in bubbles, replies full width, day headings ("Today", "Yesterday"), and a typing indicator that counts the seconds. Replies keep their paragraphs and lists (dots, numbers, hanging indent); an unsent draft waits in the input bar.
• Web search for news, weather, rates: the model searches on the server with its provider's search tool; the phone's 2007 browser is not involved. Sources are listed under the reply.
• Reading mode (key 7): one reply full width, page by page, whole lines only, page number and progress line. It keeps its place when you change the text size (key 9) or load the rest.
• Long replies in parts: "0 · Show the rest" fetches the next part from the server for free; the model is not asked again.
• Message actions: select a message with 1/3, press the centre key: shorten, explain more simply, translate, ask about it, open it in the editor. They only fill in the editor; nothing is sent until you press Send.
• Earlier chats from the server, continue any of them; pin the ones you want to keep at the top (kept until unpinned), delete or search all chats (no Turkish letters needed: "sise" finds "şişe"); optional offline copy of the last chat.
• Save to phone: a reply as a .txt file (memory card if there is one), readable later without the network under "Saved".
• Calendar and to-do: ask "add to my calendar: dentist tomorrow at 3" and the reply carries a ready entry; the centre key opens a prefilled form, and only your "Save" writes it to the phone's own calendar or to-do list. Works from any message too.
• Voice messages: press Dictate, speak up to 30 seconds; the server turns it into text, which opens in the editor so you can check and fix it before you send it.
• Photos: take one with the camera or pick one from the phone and ask about it ("what is this?", "translate this sign", "read this label"); follow-up questions in the same chat still see it.
• Your notes for the AI (Settings): "I'm Emir, I live in Istanbul, keep it short" is sent with every message.
• Data usage: requests and approximate kilobytes today and in total.
• 20 quick prompts (search the web, weather, translate, reply to a message, add to my calendar, summarize, fix my writing, ...).
• Short notes, details on request: info and errors are one line; select one (1/3) and press the centre key for the explanation; setup and settings screens keep theirs under Options > Info.
• Setup wizard on first start: server address, connection test, pairing with a 6-digit code (no long code to type); the language follows the phone. A build that names its server skips to the pairing.
• Keypad-first: every screen works with the keypad (on QWERTY phones like the E63, the digits printed on the letter keys); a Shortcuts screen lists every key. Retry after an error is one key and never charges twice.
• Eight languages: English, Türkçe, Español, Português, Français, Deutsch, Русский and Bahasa Indonesia. The app opens in the phone's language (English for any other) and changes under Settings > Language. The replies follow the language you write in, whatever the menus say.
• Look and feel: every screen except text entry is drawn by the app: line icons with smooth edges, lists with two-line rows, settings with switches that save at once, full screen. Light, dark or automatic (dark in the evening) look, three text sizes, start-up animation and jingle, reply chime, vibration and backlight. Texts are fitted to the screen.

On the server

• One Go binary / Docker image that speaks TLS 1.0 to the phone with a certificate from your own private CA, and modern HTTPS to the model providers: Claude (official SDK), OpenAI and xAI Grok (Responses API) and Google Gemini, listed in one MODELS setting with a DEFAULT_MODEL.
• Per-device access tokens through pairing, daily request, token, web-search, voice-message and photo limits, no automatic retries of paid calls.
• Optional speech-to-text for voice messages (OpenAI), with a minimal ffmpeg in the image for the phone's AMR recordings.
• SQLite for chats (30 days, pinned ones until unpinned), search over them, admin API on localhost only.

Home	Waiting for a reply	Lists and paragraphs	Reading mode
A calendar entry, selected	Message actions	Quick prompts	Dark theme, large text

Screenshots are from the FreeJ2ME emulator in the app's test mode (the "[Test mode]" replies are fake and cost nothing; the emulator reports no calendar API, so the harness turns the calendar actions on for these screens and never saves); the cover is a drawing. Start-up animation: docs/images/splash.gif.

Independent side project. Not made, endorsed or supported by Anthropic, OpenAI, Google, xAI or Nokia. See TRADEMARKS.md.

Tested on a Nokia 6300 (RM-217, firmware V06.60), and on a Nokia E63 (Symbian S60 3rd Edition FP1, 320x240, QWERTY, over WLAN; see docs/SETUP.md). Other Series 40 phones (CLDC 1.1 / MIDP 2.0, 240x320) may work but are untested.

Nokia (Java ME app) --HTTPS: TLS 1.0, RSA, no SNI, cert from YOUR private CA--> claude-s40-server --HTTPS--> Claude / OpenAI / Gemini / Grok APIs
                                                                                     |
                                                                              SQLite (Docker volume)

A 2007 phone cannot speak modern HTTPS: the Nokia 6300 offers only TLS 1.0 with RSA key exchange, sends no SNI, and its root store stops around 2008. Public clouds (including Cloudflare) refuse that handshake. So the server terminates TLS itself with a certificate from a private root CA that you put on the phone once. Details and measurements: docs/ARCHITECTURE.md.

git clone https://github.com/emir/AIKON.git
cd aikon

Full guide: docs/SETUP.md. In short:

1. A Docker host with a public IPv4 and TCP 443 (a $4-6/month VPS is enough).
2. server/scripts/pki.sh ca ~/.config/claude-s40/pki and server/scripts/pki.sh server ~/.config/claude-s40/pki <server-ip>.
3. server/deploy/push.sh root@<server-ip> --execute (starts in test mode, no API cost).
4. echo GATEWAY_URL=https://<server-ip> > app/app.local.properties && make -C app, then install app/dist/AIKON.jad/.jar on the phone.
5. Put the root CA on the phone (server/deploy/serve-ca.sh, compare the fingerprint).
6. On the phone the setup wizard walks through the connection test and pairing; approve the code with server/deploy/admin.sh root@<server-ip> pair <code>.
7. server/deploy/set-key.sh root@<server-ip> (Claude; add openai, gemini or xai for the others), then S40_MOCK=0 S40_MODELS=... server/deploy/push.sh root@<server-ip> --execute to go live.

make test          # server: go vet + go test -race; app: build + package checks + reproducibility
make -C app        # phone app only (downloads pinned build tools to app/.deps)
make -C server test

Requirements: Go 1.26+, JDK 11+, Python 3 with Pillow, Docker (for deployment), OpenSSL or LibreSSL.

• The API keys live only on your server. The phone gets a per-device, revocable access token through pairing.
• Chats are stored on your server for 30 days after the last message; pinned chats until you unpin or delete them. The phone keeps the last chat only if you turn on "Keep last chat on phone"; replies you save and calendar entries you add stay on the phone. Your notes for the AI are stored on the phone and sent with each message (never logged).
• The setup (server address, access code, notes) is also kept in a file on the memory card so a new build needs no new pairing; revoke the device if the card leaves your hands, or use Settings > Reset setup. Logs contain no message text.
• Every message is an API call to the chat's model, billed to your key with that provider. The server enforces per-device daily request, output-token and web-search limits and never retries a paid call automatically. Web searches are billed per search and their results count as input tokens. Set a spending limit in each provider's console.
• Voice messages (off unless you turn them on) go to OpenAI's speech-to-text, billed to your OpenAI key. The recording is not stored; the text is kept for a day so a retry never pays twice.
• Photos are scaled down to 1024 pixels and kept on your server with their chat (30 days, or until you delete it); each photo adds about 1000 input tokens to the messages of its chat.

The app is written in English; every other language is one text file, app/lang/xx.txt: an English text, a TAB, its translation, one per line. The Spanish, Portuguese, French, German, Russian and Indonesian files are first drafts: corrections from native speakers are very welcome (a pull request that edits the file is enough). A new language is a new file plus its code and name in L.java (LANGS, NAMES); make -C app langs shows what each file covers, and the build refuses a file that misses a text. Languages written right to left (Arabic, Hebrew) need layout work first, and scripts the phones' fonts lack (Japanese, Chinese) are out of reach on this hardware.

• Andrew Barnes (@Bortlesboat)
• Alex Halloran (@XanderHalloran)

MIT, see LICENSE. Copyright (c) 2026 Emir Karşıyakalı. Build-time tools are downloaded, not bundled (ECJ: EPL-2.0, ProGuard: GPL-2.0, MicroEmulator API stubs: LGPL); none of them end up in the phone app. The optional emulator harness app/emu/EmuShot.java links against FreeJ2ME (GPL-3.0), which is not included.