A reading room for opencode
Folio is a desktop app for opencode. Each session becomes a chapter you can read: your request in ink, every command a footnote, every edit a plate you accept or reject.
Free · MIT · macOS, Windows and Linux · version 0.3.0
A real session on opencode 2.0.32. opencode named the chapter from the request, and the edit it made faces the page as Plate I.
How it reads
Folio doesn't change what opencode does. It changes how you read it, so you can follow a long session the way you follow a chapter.
Open a folder and it becomes the book. Contents lists every chapter, the ribbon marks your place and search looks through all of it.
opencode names each one from what you asked. You write in ink at the foot of the page and press Return twice to send.
Every file read and command run settles into a numbered note3–7 under the prose, so the reasoning stays readable.
Each edit is a diff set on the facing page, captioned like a figure: Plate I, the file, lines added and removed.
You stay in charge
When opencode changes a file, the diff faces the page that explains it. Four words sit under it:
Turn on Ask before the press writes in the menu and opencode stops before each edit and each shell command. The question sits at the foot of the page with the proposed change facing it.
The answers are Allow once and No. There's deliberately no “Always”: in opencode that saves a rule for the whole project, and one click would quietly switch the setting off.
The installer carries opencode 2.0.32 and starts it for you on a random local port, with a password made for that launch. It keeps its own sessions and keys, so your opencode setup stays untouched.
The free OpenCode Zen models work without a key. Paste a key for another provider if you have one, or attach Folio to an opencode server you already run.
Original, Quiet, Paper, Bold, Calm and Focus each pair a typeface with a palette in both appearances. Text size, line spacing, margins and justified text are yours to set, and every theme keeps its ink readable on the page.
Highlight a passage to write in the margin. The reply sits beside your note and can replace the passage.
The catch
Folio is young. Here is what that means today.
This is version 0.3. The core works and has 364 tests behind it, but expect rough edges, and please report them.
macOS and Windows will warn the first time you open it. The steps to get past that are below, next to each download.
OpenCode Zen decides which free models exist and how much you can use them. They can be busy or rate limited. A provider key avoids that.
opencode reads files and runs commands in the folder you open, as it does in the terminal. Turn on Ask before the press writes if you want to approve each step.
There's no file tree, terminal or code editor. Keep your editor open next to it; Folio is for following and steering the agent.
The Intel dmg is cross-built on an Apple silicon machine and hasn't been run on an Intel Mac yet. If it misbehaves, tell us.
Download
Every file is on the GitHub release page, built by GitHub Actions from the public source.
.dmg · macOS 12+ · Apple silicon or Intel
xattr -dr com.apple.quarantine /Applications/Folio.app in Terminal, then open it again.-setup.exe or .msi · Windows 10+ · x64
.deb or .AppImage · x86_64
sudo apt install ./ followed by the .deb file name.Rather build it yourself? You need Node 22 and Rust. The README has the three commands.
FAQ
Yes. Folio is open source under the MIT license. There is no account and nothing to buy. The free OpenCode Zen models need no key; other providers bill you directly if you paste their key.
No. The installer carries opencode 2.0.32 and starts it for you on a random local port with a password made for that launch. You can also attach Folio to an opencode server you started yourself.
No. opencode does the work. Folio is a different way to read and steer it: it talks to opencode's own HTTP API and does not fork or patch it.
The bundled opencode keeps its sessions, keys and cache in Folio's own app data folder. It never opens your opencode database, and your opencode config folder stays yours.
Folio itself sends nothing to Basalt. opencode sends your prompts and the files it reads to the model provider you choose, the same as it does in the terminal.
The build isn't signed with an Apple Developer ID yet. Open System Settings, then Privacy & Security, and click Open Anyway next to the message about Folio. If macOS says the app is damaged, run xattr -dr com.apple.quarantine /Applications/Folio.app in Terminal and open it again.