Expose the mailbox to an LLM client (Claude Desktop / Code) over an
in-process MCP server, so the bridge itself hosts it and the GUI controls
it live. Strictly read-only: there is no tool that sends, moves, deletes or
mutates mail — by design and asserted in tests.
Transport: Streamable HTTP (MCP 2025-06-18) on a single POST /mcp endpoint
bound to 127.0.0.1, answering each JSON-RPC request with application/json
(no SSE — the server never pushes). Auth is a bearer token (the bridge
password); the Origin header is validated to block DNS-rebinding.
Permission tiers (config.McpPermission, default Disabled = server off):
- Metadata — folders, metadata search (subject/sender/date), headers only.
- Full — the above plus full-text body search and message body text.
Tools: list_folders, search_messages, list_unread, get_message. Search
combines subject/sender always and the encrypted FTS body index under Full;
get_message returns headers always and body only under Full.
Wiring: spawned in-process by both the CLI (main.rs) and the GUI bridge
task (bridge.rs); a Disabled tier makes serve() a no-op, and it is kept out
of the select! so it never triggers teardown. GUI gains an MCP section
(tier selector, port, full-read warning, "copy client config" button) and a
get_mcp_client_config command that emits the ready-to-paste client snippet.
Validated live on a ~19k-message mailbox: initialize / tools/list /
tools/call all conform; 401 without the bearer token, 403 on a foreign
Origin, 202 on notifications; list_folders, body search and get_message
(HTML stripped to text) all return correctly. 240 unit tests.
The bundled-sqlcipher feature relied on a system OpenSSL for SQLCipher's
crypto — fine on macOS/Linux, but absent on Windows, where the release
build failed at libsqlite3-sys. Switch to
bundled-sqlcipher-vendored-openssl: OpenSSL is built from source, so the
build is self-contained and identical across all three OSes (and the AUR
package needs no system OpenSSL). Caught by the multi-OS release dispatch.
The keyring dep was hard-pinned to the macOS `apple-native` feature, so
the headless CLI/core didn't compile anywhere else — blocking an AUR
package or any Linux/Windows use. Split it into per-target features:
apple-native (macOS), windows-native (Windows), and
sync-secret-service + crypto-rust (Linux, via gnome-keyring/KWallet,
pure-Rust crypto so no OpenSSL build dep).
TutaBridge links Tuta's Rust SDK, which is part of the GPLv3-licensed
tutanota project, so the bridge must carry the same license. Add the
full GPLv3 text, set `license = "GPL-3.0-or-later"` on all three
crates, and note it in the README.
Split the bridge into a tutabridge-core crate, a Tauri v2 desktop app
(src-tauri) and a React/TS UI (ui), keeping the CLI entrypoint at the
workspace root.
Add encrypted local storage (SQLCipher metadata index + encrypted .eml
files) so mail persists across launches and only the delta is fetched.
Wire the bridge to the Tuta Rust SDK via the tuta-repo submodule
(batch loading, MailDetailsBlob reading, interactive 2FA login).
Implement SMTP sending: build the draft and send it through Tuta's
DraftService/SendDraftService, mirroring the web client (body in
compressedBodyText, non-empty sender/recipient names, populated
SendDraftParameters). Add unit tests for the draft/send payload building.
Anthony