Oreneta

Oreneta is a fast desktop mail and calendar app with chat and kanban views, and native Microsoft Exchange (EWS) support. Oreneta is Catalan for the swallow — the bird that always finds its way home.

It is a fork of Meron by Nonbili Inc., which declined native Exchange support upstream. Oreneta carries everything Meron does, plus:

• Native Exchange (EWS): mail against on-premise Exchange servers with no IMAP bridge in between — folders, incremental sync, send, flags, move.
• A full calendar: agenda, day, week and month views; events created, edited and deleted on the server; recurring series expanded server-side; in the day and week views, events dragged to move or resize them, dropped on the mini calendar, or created by dragging a range, from a slot's menu or from the keyboard (Exchange events not yet).
• Calendars from anywhere: an account's calendars arrive with the account (Exchange, Google Calendar), alongside local calendars and read-only subscriptions to published .ics addresses.

Delivery roadmap

The completion plan (2026-10-09) orders the remaining work into three declared candidates and sixteen iterations, each with its required tests, and defines the verification levels and quality gates. The competitive delivery plan and backlog audit record the 2026-10-05 execution review. The eM Client parity plan tracks the frozen reference, sprint backlog, architecture gates and acceptance evidence. It is a delivery target, not a claim that Oreneta has already reached parity.

Building

cargo build --manifest-path meron-core/Cargo.toml --bin oreneta-core  # the Rust engine
wails build -tags webkit2_41                                         # the desktop app

Google sign-in: use your own credentials

Exchange, IMAP and Outlook accounts need nothing here — this section is only about signing in with Google.

The Google OAuth credentials compiled into this source tree are Meron's, inherited when Oreneta forked from it. Do not ship builds that use them: Nonbili paid for the verification behind that OAuth client, and borrowing it would show Meron on the consent screen, spend their quota, and put their verified status at risk for users who are not theirs.

Point a build at your own Google Cloud project instead. Both the Go app and the Rust engine read these, and they take precedence over the compiled values:

export MERON_GOOGLE_CLIENT_ID="…apps.googleusercontent.com"
export MERON_GOOGLE_CLIENT_SECRET="GOCSPX-…"

In the Google Cloud console you will need: an OAuth client of type Desktop app (the sign-in flow redirects to loopback, which a Web client rejects), the Google Calendar API enabled, and the calendar scope added to the consent screen. An app left in Testing issues refresh tokens that expire after 7 days; publishing it to Production ends that, and no verification is required to publish — verification only removes the "unverified app" warning and the 100-user cap.

Distributing Oreneta publicly with Google sign-in working out of the box is a different matter: Gmail is a restricted scope, so it needs Google's verification, and possibly a security assessment (see docs/oauth-registrations.md for what is confirmed and what is not). Until someone takes that on, public builds should ship without Google sign-in — Gmail still works over IMAP with an app password, and Google calendars can be subscribed to read-only through their secret .ics address.

Build anything you distribute with -tags distributable. That build compiles in none of the inherited values — the Microsoft client ID was inherited too — and turns off each sign-in that has no Oreneta-owned client injected at build time, instead of falling back to Meron's. The inventory, the injection flags and the tests are in docs/oauth-registrations.md.

License

Oreneta is licensed under the GNU Affero General Public License v3.0, as is the Meron code it is built on. Copyright (C) 2026 Nonbili Inc. for the original work; Copyright (C) 2026 Adil El Haji for the fork's changes. Internal module and crate names keep Meron's naming on purpose, so upstream fixes keep merging cleanly; what users see, such as the engine process oreneta-core, is named after Oreneta.