Blog Urbit April Developer Newsletter

Jeremy Tunnell at

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The Urbit Developer Newsletter ~2023.4

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Lots has happened since February:  the Volcano Summit, a lot of runtime releases, and many apps.

  • The Urbit Foundation core development team meets publicly every morning at 8am PT to review and merge open pull requests. Join us in the Hacker House to participate.

  • We often discuss upcoming releases in the Zero K podcast — subscribe for alpha.

  • We’re moving the [bp] newsletter to a bimonthly cadence. Expect the next one in June accompanying our next Developer Week.

  • Our Build Parties feature live programming in the Hacker House where we build apps from scratch. Check the [bp] group at ~dister-dozzod-lapdeg/battery-payload for details or follow us on Twitter.

    • ~mastyr-bottec and ~lagrev-nocfep built %tell on March 31st, an application for stars to send a DM to all sponsored planets at once.  Check it out here.

    • ~tamlut-modnys and ~lagrev-nocfep built a code grading tool, %grader, on April 14th.

    • After %grader ~lagrev-nocfep and ~midden-fabler kept working on %global-store: a basic per-app key-value store.

    • There’ll be at least one more Build Party in April.  Watch for announcements in the [bp] group and on Twitter.

  • Hoon School began in March.  It’s a little late to jump in now, but we’ll have another cohort starting in June 2023: sign up here.

  • App Workshop has began two weeks ago. App Workshop is for developers who want to produce more complex apps after Hoon School and App School.  There’s still time to dive in.  

New Apps and Updates

Things are popping—Urbit has doubled its number of active developers since last year. ~norsyr-torryn noticed that Hoon is now in the top 50 languages by pull request volume on GitHub. And Volcano Summit saw a lot of new secrets unveiled for the first time publicly. In no particular order, the past couple of months saw:

  • Pongo, a new chat app from Uqbar

  • %blog, a proof of concept that has caught on fire by ~dachus-tiprel

    • |install ~hanrut-sillet-dachus-tiprel %blog

  • Board, for tiny home pages in a grid

    • |install ~dister-hanfel-dovned %board

  • Lure, a new system for inviting users to use the Tlon suite (Homestead)

  • Talk mobile interface from Tlon

  • %plug, ecommerce selling products using Urbit, by ~hastyp-patmud and team

    • |install ~hastyp-patmud %plug

  • Portal, a stylish landing page and group discovery by ~doplyr-harbur, ~toptyr-bilder, et al.

    • |install ~worpet-bildet %portal

  • Aera, for reputation management

  • Vaporware for NFTs and web3 experiences leveraging Urbit by ~harden-hardys, ~rabsef-bicrym, and team

    • ~ligbel/vaporware

  • Studio has some new updates for $$$ subscriptions, by ~tirrel

  • Hoon-native UI by ~hastuc-dibtux now has a demo

  • Replit integration for Urbit has been advanced by a team including Holium and the UF

  • GroundSeg from Native Planet now has a Dev Mode for Dojo access

  • ~fasner-bitful pushed some whimsical Hoon reference sheets


The Urbit runtime updated from 1.22 on February 14 to 2.1 on March 28. The main highlight for developers and users is the introduction of the 8 GB loom. The loom size can be set at the command line when starting Urbit by including the flag `--loom 32` for 4 GB or `--loom 33` for 8 GB (set by powers of 2 in bytes).

Urbit OS cooled its kernel from 415 K to 414 K. Other than SSS, many of these improvements were quality-of-life changes:

The next release of Vere in May will include:

  • Remote scry to allow subscribers to read data from the runtime without generating an Arvo event, leading to better scaling.

  • Eyre cache to add scry and noun caches.

  • Noun channels to support jammed (serialized) nouns over HTTP and eliminating some need for JSON conversions in Hoon.

  • JSON jets to support faster JSON encoding and decoding.

Some new Urbit OS concepts were previewed at the volcano and subsequently (in an instance of linguistic maximalism maximalism):

  • Scry maximalism, using runtime-resolved scry requests for essentially all data comms

  • Loom maximalism, with 8 GB landing in February and New Mars aiming for arbitrary memory

  • Large atom storage, with a separate memory arena

  • Quickboot (<1s time per ship)

  • For more, see the Twitter thread

  • Numerical computation roadmap

Notable Tweets

@urbitfoundation has been actively posting about technical topics lately:

@NativePlanetIO posted a a thread on hosting your own Urbit server with their open-source software.

Next Kelvin

The next kelvin release is scheduled for ~2023.5.9 and will require a runtime upgrade. It contains major improvements. Core developers will begin testing that release on live ships this week, and a release candidate will land for application developers on ~marnec-dozzod-marzod on ~2023.4.25. Read more on the Urbit Foundation group in the Infrastructure channel.





Jeremy brokers the sale of galaxies and stars. To purchase or sell a galaxy or star contact him at [email protected]

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