emersion/hydroxide
A third-party, open-source ProtonMail CardDAV, IMAP and SMTP bridge observed · 2026-08-28
Health v2 · maintenance only
10/100
- Activity 95
- Release rhythm 59
- Longevity 100
Flags: archived
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.
- gap_med: 147.0
- age_days: 3299
- days_rel: 115
- days_push: 31
- n_releases_24m: 3
Adoption not part of the score
2176 stars · 183 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
Hydroxide is a third-party, open-source ProtonMail bridge written in Go that translates standard protocols (IMAP, SMTP, CardDAV) into ProtonMail API requests. It runs as a headless CLI server designed for power users who want to use standard email clients or git-send-email with ProtonMail.
Use cases
- access ProtonMail from a standard email client via IMAP
- send email through ProtonMail using SMTP from any mail client
- sync ProtonMail contacts with CardDAV clients like Evolution or DAVdroid
- use git-send-email with a ProtonMail account
- run a ProtonMail bridge on a headless server without a GUI
- self-host an open-source alternative to the official ProtonMail bridge
When to choose
- you want a fully open-source, GUI-free ProtonMail bridge for a server or headless environment
- you need standard-protocol access (IMAP/SMTP/CardDAV) to ProtonMail for clients like Evolution, DAVdroid, or git-send-email
- you prefer a lightweight CLI tool over the official proprietary bridge
When to avoid
- you need polished, fully-supported IMAP support - it is explicitly work-in-progress with unencrypted local connections only
- you want a graphical desktop app or official vendor support
- you need Microsoft Outlook compatibility - the project explicitly does not target it
- you expect actively maintained software - it is casually maintained and has migrated to Codeberg
Facets
service · maturity maintenance
email http-server security cryptography email privacy self-hosted developer-tools windows cli self-hosted go protonmail imap smtp carddav bridge headless git-send-email linux macos
6 sources
- readme: https://github.com/emersion/hydroxide · fetched 2026-08-28 · e71a52583058
- homepage: https://codeberg.org/emersion/hydroxide · fetched 2026-08-29 · ed730dc2da50
- site_page: https://docs.codeberg.org/getting-started/what-is-codeberg · fetched 2026-08-29 · fe3047f34c81
- site_page: https://docs.codeberg.org/getting-started/faq · fetched 2026-08-29 · 7ffd1ab1d66b
- site_page: https://docs.codeberg.org · fetched 2026-08-29 · 3c642f9d47c9
- site_page: https://codeberg.org/emersion/hydroxide/releases · fetched 2026-08-29 · e291b0ad99ad
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| emersion/hydroxide | main | 10 |
For agents
markdown · JSON · MCP: product_card(name="emersion/hydroxide")
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem