Opencode OpenSpec plugin

A TUI sidebar for opencode that brings the OpenSpec workflow into the terminal. Your specs and in-flight changes sit next to the chat, and the buttons hand the work to the agent – so you drive spec → change → implement → archive without leaving opencode.

What you get

Specs, browsable. Every capability under openspec/specs/ is listed with its requirement count. Open one to read its Purpose and requirements; open a requirement to unfold its When/Then scenarios.

Search that goes all the way down. Type in the search box above the list and it filters on everything a spec contains – name, title, Purpose, and the text of every requirement and scenario. Multi-word queries have to match all words, but they can match in different places. Rows report how many requirements matched, so you can see where the hit came from. The query follows you into a spec and filters its requirements there too.

Changes with live progress. Active and completed changes each get a section, with a task-progress bar per change and a rolled-up bar on the collapsed header. Open a change to see its tasks grouped and ticked off as the agent works – the sidebar re-reads the files every few seconds, so it keeps up on its own.

Buttons that write the prompt for you. Explore, Propose, Apply, Update, Archive and Delete are all there. Apply and Update drop the command into the prompt so you can add context before sending; Archive and Explore submit right away. Everything that starts an agent turn greys out while one is already running.

Setup and updates handled. A first-run Init button installs the OpenSpec CLI, configures the project and derives specs from your existing code. Settings shows the installed plugin and CLI versions, checks npm for newer ones, and can apply the update for you.

Requirements

• opencode >= 1.18.0
• The OpenSpec CLI, installed globally – the /opsx-* commands shell out to the openspec binary. Either install it yourself (npm install -g @fission-ai/openspec) or let the Init button do it.

Install

TUI plugins are configured in opencode's tui.json, not opencode.json. Add the plugin to ~/.config/opencode/tui.json:

{
  "plugin": ["@vladislavlad/opencode-openspec-plugin"]
}

opencode resolves the package from npm on the next launch. The sidebar appears in the session panel – open it in a project that has, or is about to have, an openspec/ directory.

First run

In a project with no OpenSpec set up, the sidebar shows an Init button. It hands the agent one turn that:

1. installs the OpenSpec CLI if it's missing (it'll ask which package manager to use);
2. runs openspec init --tools opencode, which writes the /opsx-* commands and skills into .opencode/;
3. asks about your stack, spec language and project context, and writes them to openspec/config.yaml;
4. offers to reverse-engineer baseline specs from your existing code – and asks how deeply to study it first, since Deep costs noticeably more time and tokens than Overview;
5. validates the result and points you at Explore and Propose for your first change proposal.

Progress is checkpointed stage by stage. If the turn is interrupted, the sidebar says where it stopped and offers Resume – which picks up from the first unfinished stage – or Dismiss.

The commands from step 2 only load properly when opencode restarts, so you'll see a Reload OpenCode prompt once setup finishes.

Commands

The plugin registers two of its own (type / in opencode):

Command	What it does
/opsx-config	Configure project context – stack, spec language, rules – in openspec/config.yaml.
/opsx-baseline	Derive or refresh openspec/specs from the existing implementation. Needs a configured project – run /opsx-config first.

The rest come from the OpenSpec CLI after openspec init:

Command	What it does
/opsx-propose <feature>	Create a change proposal for a new feature or change.
/opsx-apply <change>	Implement an approved change.
/opsx-update <change>	Revise an existing change proposal.
/opsx-archive <change>	Fold a completed change back into the specs.
/opsx-explore	Explore the specs and codebase before proposing.
/opsx-sync	Reconcile specs with the current state.

Staying up to date

The sidebar checks npm once per project for a newer plugin or CLI version. When there is one, a banner appears above the actions and the Settings button turns accent-coloured. From Settings you can update either component or both; the agent edits your tui.json, installs the new CLI, and tells you to reload. After the restart, Complete Update runs any migration steps and summarises what changed.

You get that summary however you updated. The sidebar also remembers which plugin version last ran, so an update that bypassed the button entirely – npm i -g, a hand-edited tui.json, or an unpinned specifier that opencode refreshed on its own – still offers Complete Update on the next launch.

Development

Built with Bun. Sources in src/ are bundled into a single dist/index.js using @opentui/solid's Solid transform (universal codegen). @opentui/* and solid-js stay external, so the plugin shares opencode's single Solid runtime at load time.

bun install

bun run build

bun run test

The published package ships only dist/; prepublishOnly rebuilds it before every publish so the artifact always matches source. See AGENTS.md for the code layout and conventions.

Release

Pushing a v* tag builds and publishes to npm – see .github/workflows/release.yml.

npm version patch && git push --follow-tags

License

MIT © Vladislav Kartashov