jmapfe

JMAP mail client for people who want modern mail without a cloud middleman.

jmapfe is a free/open-source project building a cross-platform JMAP client from one TypeScript codebase. Target platforms are web, Android, Linux desktop, Windows desktop, and macOS desktop. Desktop uses a local Tauri bridge so the app can talk directly to JMAP servers without browser CORS limits.

Why

Email clients are often locked to IMAP-era assumptions or hosted services. JMAP gives mail, contacts, calendars, blobs, quotas, rules, sharing, and push a typed JSON protocol. jmapfe aims to make that usable for normal people while keeping power-user control.

Core goals:

• No mandatory central service.
• Direct connection to user-owned JMAP accounts.
• Typed protocol code, not stringly-typed request blobs.
• Secure credential storage per platform.
• Offline-ready local storage and sync.
• Full JMAP surface over time: mail first, contacts/calendars next.
• Accessible, fast, compact UI.

Status

Early, active, usable foundation. Expect rough edges.

Current codebase includes:

• Expo + React Native Web app shell.
• Tauri desktop shell and local JMAP HTTP bridge.
• Account setup with JMAP discovery and credential verification.
• Typed JMAP core request/session/transport helpers.
• Mail folder/message UI, message actions, attachment open/download paths.
• SQLite store/sync package foundations.
• Test fixtures for protocol and sync work.
• Linux AppImage packaging fixes for Expo asset paths and WebKitGTK runtime behavior.

Web Limitation

Browser builds can only connect to JMAP servers that allow the app origin with CORS. This is a browser security rule. Desktop and native builds avoid that limit through platform networking/local bridge code.

Repo Layout

apps/
  web/                 Expo / React Native Web app
  desktop-tauri/       Tauri desktop shell and Rust bridge

packages/
  app-core/            account setup and shared app models
  jmap-core/           RFC 8620 core helpers
  jmap-mail/           mail protocol package foundation
  jmap-contacts/       contacts package foundation
  jmap-calendar/       calendar package foundation
  jmap-extensions/     common JMAP extensions
  store/               SQLite schema/repository foundation
  sync/                sync engine foundation
  ui/                  shared UI package foundation
  platform/            platform adapter foundation
  mime/                MIME package foundation
  openpgp/             OpenPGP package foundation
  test-fixtures/       fake transports and test data

PROJECT.md is long-form product/spec direction. Treat specs as source of truth for protocol work.

Quick Start

Requirements:

• Node.js compatible with npm 10.
• Rust toolchain for Tauri desktop work.
• Platform dependencies for Tauri on Linux if building desktop bundles.

Install:

npm install

Run web dev server:

npm run dev:web

Run desktop dev shell:

npm run dev:native

Check code:

npm run typecheck
npm test

Build web assets:

npm run build:web

Build Linux desktop bundle:

npm run build:linux

Help Wanted

Good first areas:

• Provider testing: Fastmail, Stalwart, Cyrus, Apache James, other JMAP servers.
• UI accessibility, keyboard flow, screen reader labels.
• Mail UX polish: search, threading, message states, attachments.
• Local store and offline sync hardening.
• Contacts and calendar package implementation from specs.
• PGP/MIME parsing, verification, signing, encryption.
• Android build/dev workflow.
• Documentation, screenshots, install guides.
• Tests for protocol edge cases and error handling.

Project Values

• User accounts stay user-controlled.
• Secrets never go into logs, localStorage, fixtures, or commits.
• Protocol errors should be visible and recoverable.
• Small, reviewable changes beat giant rewrites.
• Specs win over guesses.
• FOSS collaboration should be welcoming and direct.

Contributing

Read CONTRIBUTING.md. Bug reports, provider reports, docs, tests, and small focused PRs are all useful.

License

jmapfe is licensed under the MIT License. See LICENSE.