Update for the week ending on Friday, Oct 16, 2026

mtlynch.io

• Started September 2026 retro
• Started writing “The mustCreate Pattern for Go Tests”
• Rolled back launch discount in Refactoring English ad
• Deleted dead social links
• Update my author photo
• Updated my .gitignore with AI-agent ignores
• Switched code blocks to VS Code style
  • I’d had them a dark style, but I recently was convinced it’s better for light mode text to be with light mode code blocks
• Removed a workaround for the <base> tag in preview deploys

Refactoring English

• Ordered print books for all Kickstarter premium backers

Book

• Bumped to 1.0.11 and ordered a new test print
• Added support for font ligatures
• Got rid of bulleted lists where the top-level item was only a single element
• Fixed more awkward page breaks
• Fixed the visual diff to ignore tiny shifts from float arithmetic
• Reformatted footnotes so they appear immediately after punctuation rather than before
• Removed spell check squiggles from three screenshots

Website

• Turned off launch week pricing
• Improved purchasing power parity scripts

Feedback Site

• Added logic to store new style user IDs for new user signups
  • I’m still transitioning from Buttondown-based IDs, and this way, there’s less delicate timing to when I do the final migration
• Ported improvements from go-app-starter

Backend

• Ported improvements from go-app-starter

Little Moments

Little Moments is an open-source web app I’m working on to replace the current family photo sharing app (TinyBeans) I used (which I strongly dislike).

• Ported improvements from go-app-starter
• Fixed a bug where encoded media content types depended on host MIME mappings
• Refactored code to share between production and development Nix apps
• Refactored test code to get rid of helper functions

ScreenJournal

ScreenJournal is basically Goodreads, but for TV and movies. Or letterboxd, but focused on small communities.

• Moved the repo from GitLab to CodeFloe
• Added a NixCI build workflow
• Dropped Nix VCS stamping
  • It’s neat, but it screws up Nix build caching, which is expensive for CI
• Switched SMTP host to sendamatic
• Replaced repetitive test helpers with a generic implementation

Weekly Snippets

• Reduced Forgejo requests to avoid triggering 429 errors on Codefloe
• Excluded merge commits from forge activity
• Re-sorted forge activity from oldest to newest
• De-duplicated Forgejo merged pull commits

go-app-starter

• Backported improvements from child repos
  • Correct external Go test package guidance
  • Fail when flake target builds fail
  • Limit Playwright workers to available cores
  • Lint and typecheck E2E TypeScript
  • Modernize Air development reloads
  • Narrow Go test build inputs
  • Upgrade Playwright to 1.59.1
  • Upgrade evolutionary migrations
  • Prefer accessible Playwright locators
  • Remove VCS stamping
• Matched the project to the AGENTS.md conventions
  • Place Go package declarations after imports in contributor guidance
  • Allow filesystem writes in end-to-end tests, not unit tests
  • Permit the existing Nix development workflow exceptions
  • Stop HTTP tests when response statuses do not match expectations
  • Use one E2E runner and worker policy in Nix and local builds
  • Exercise registered static routes in cache and range tests
  • Include failure causes in HTTP errors and contextual logs
  • Consolidate comment punctuation and documentation formatting
  • Expose one canonical Nix package name per app build
  • Expose visit-count updates as an accessible status
  • Run Fly deployment through a standalone script
  • Use Nix-provided Go analyzers from PATH
  • Use an injected clock for page timestamps and static cache versions
• Added better Go test guidance
• Excluded the pnpm lockfile from Prettier

NixOS Config

• Upgraded to opencode v2
  • Enjoying it a lot
  • I find it easily extensible, though I’m not sure how much of a difference it was from v1 because I didn’t bother extending v1 because I didn’t want to have to port everything to v2.
• Switched my AI sandbox from Podman containers to microVMs
  • I had been working on this before the opencode v2 switch, but I had to rush it through because v2 doesn’t work with Podman the way I’d done before
  • The main issue is that v2 expects to own its database exclusively, whereas v1 either didn’t or was more tolerant of shared access. I have many containers sharing a single database through a folder mount, but I can’t do this in v2.
  • New solution is that I have a single OpenCode VM as a monolithic sandbox. I lose intra-project isolation, but I get stronger guest-host isolation because it’s a separate OS kernel.
• Gave the AI sandbox credentials to a separate mtlynch-bot account on Codefloe
  • The account has read-only access to all of my private repos, so it can make PRs but can’t merge them
• Added an OpenCode skill to request code review from Claude Code + Fable 5.1
• Added an OpenCode “AFK mode” where it completes a task without stopping to ask me questions
  • I hate leaving a job running overnight and finding that it didn’t make progress because it stopped to ask me a question

Grosiree

Grosiree is a shared grocery list web app I’m making with my wife to show her how vibecoding works.

• Ported improvements from go-app-starter

Home Network Manager

• Started experimenting with an idea to replace my OPNsense router at home.
  • A domain-specific language that lets me define my network layout and firewall rules at a high-level
  • A domain-specific language that lets me write assertions about my network (e.g., printer VLAN cannot make outbound requests to the Internet)
  • A system that converts the rules into FreeBSD router config and then deploys a virtual network of VMs to test the rules and verify the assertions are correct
• The motivation is that I find it so easy to accidentally regress behavior when I’m configuring OPNsense, and I often don’t notice until weeks later (e.g., my wife discovers she’s unable to print when she needs to print)

PicoShare

PicoShare is a minimalist web-based file sharing tool I’m working on. I’m often frustrated that I can’t just send someone a link directly to a file because every file-sharing service tries to re-encode images/video or wrap their own viewer around other files, so I’m making a simple self-hostable tool that lets you upload files and share them with other people.

• Ported improvements from go-app-starter
• Fixed video playback in Chrome
• Accepted a PR to upgrade Alpine runtime image to 3.24

Maildir Viewer

• Ported improvements from go-app-starter

beancount-chase-bank

• Added support for incoming real-time payment credits
• Added support for international incoming wire fees
• Added support for incoming wire transfers
• Simplified parser regexes

Misc

• Co-hosted the Indie Founders Western Mass meetup
• Did monthly bookkeeping