MeasyCode for VS Code

AI coding agent that lives in your editor.

The same agent as measy in the terminal — this is a front end for it, not a second implementation.

How it works

MeasyCode already speaks a line-oriented JSON protocol on stdio (measy -jsonl), one object per line each way, precisely so a GUI can drive the same agent loop the terminal uses. This extension spawns that process, forwards its output into the chat view, and writes commands back to its stdin.

That is deliberately all it does. Which tools exist, when approval is needed, how a turn ends — every one of those decisions stays in the Go process. If this extension ever starts deciding them too, the two have begun to drift, and that is the bug to fix rather than the feature to keep.

The contract is jsonl.go in the CLI repo.

Requirements

MeasyCode must be installed and on your PATH:

curl -fsSL https://github.com/measyai/measycode/releases/latest/download/install.sh | bash

irm https://github.com/measyai/measycode/releases/latest/download/install.ps1 | iex

If it lives somewhere the PATH does not reach, set measycode.binaryPath.

Signing in

Two ways, the same two the terminal offers:

Continue with MeasyAI runs the browser device flow. What comes back is a session — the same credential the website holds — and it is stored by the CLI, so signing in here signs you in there too. This is the path for a subscription, and nothing ever reaches your clipboard.

An API key you made yourself at measyai.com/app/api-keys. MeasyCode never mints keys on your behalf, deliberately: a key you did not knowingly create is one you will not recognise later and will not dare revoke.

A pasted key is kept in your editor's secret storage, never in settings — settings are plain text on disk and ride along with Settings Sync. It reaches the agent as MEASYAI_API_KEY in its environment, which is the CLI's own documented override and takes precedence over its stored credential file. That also means applying a key requires restarting the agent, which the extension does for you.

Because two credentials can be in play at once, Sign Out clears both: it sends logout to the CLI and deletes the stored key. Clearing only one would sign you straight back in on the next start.

If sign-in appears to succeed but the model list comes back empty, the key was most likely rejected — the agent reports itself ready either way. The view says so rather than letting you discover it on your first prompt.

Using it

Open the MeasyCode view in the activity bar, or press Ctrl+Shift+M (Cmd+Shift+M on macOS). The agent starts in your first workspace folder — it needs a real directory, so an empty window will ask you to open a folder first.

Select code in an editor and choose Ask MeasyCode About Selection from the context menu to drop it into the composer with its file and line range.

Two chips sit above the Send button. The first is the current model — click it for the picker, filled from your account's own catalogue rather than a list baked into the extension. The second is what is left of your rolling token allowance; it refreshes after each turn, turns amber past three quarters and red past nine tenths, and reads simply "unlimited" on a plan without a cap. It appears only when the installed MeasyCode is new enough to report usage.

Writes ask for approval before they happen. The dialog opens with Deny focused, not Allow: the agent is asking to change your files, and a stray Enter should not be what grants it. Always allow switches the session to Developer mode — the same thing /approval developer does in the terminal.

Settings

The model and approval mode are not settings here. They come from the agent's own configuration, so this extension cannot quietly disagree with your terminal about either one.

Known limitations

• The transcript is plain text. Markdown and code blocks arrive as written rather than rendered — readable, but not pretty. Rendering model output as HTML is a decision that deserves its own care around sanitisation, so it is not in this version.
• One workspace folder. The agent is started against the first folder of a multi-root workspace.
• One session per window. The protocol is a single conversation on a single pair of pipes.

Development

npm install
npm run compile      # bundle to dist/
npm run watch        # rebuild on change
npm run typecheck
npm test             # see below

Press F5 in VS Code to launch an Extension Development Host.

npm test runs the real src/agent.ts outside the extension host, with the vscode module aliased to a small stub. It covers the two things that actually break:

1. Line assembly, fed with deliberately hostile chunks. A pipe hands over whatever the OS had ready, so one data event is not one message — treating it as one works fine until a long tool body arrives.
2. The process path — spawn, handshake, polite stop — against the real measy binary, which must be installed for that half to be meaningful.

Both halves are needed. Break the buffering deliberately and the first half fails loudly while the second stays green, because a handshake is small enough to arrive in a single chunk.

License

MIT