Editor Support

Editor support

letsgo lsp [--restricted]
letsgo fmt [file|-]

Everything an editor knows about letsgo comes from the letsgo binary on the machine. There is no second copy of the directive table, the hook list or the feature catalogue living in an extension, because two copies of a closed set become two different closed sets on the first release that adds to one of them.

The language server

letsgo lsp speaks stdio JSON-RPC and serves letsgo.mod, the global config.mod and .letsgo/*.mod:

Request	What it gives
publishDiagnostics	parse and decode errors, on every change
formatting	byte-for-byte what letsgo fmt produces
completion	directive names, build targets, hooks, feature names, first-party plugins
hover	a directive's documentation
documentSymbol	an outline
codeAction	update a plugin pin

Checks that point at a line — a budget naming a target that is not built, say — carry a file:line:col position, so they appear as squiggles on save rather than as text in a terminal.

It is a plain LSP server with no client-specific extensions: Neovim's built-in client gets diagnostics and completion from the same binary VS Code does.

Restricted mode

--restricted parses, decodes, formats and completes, and does nothing else: no plan, no plugin lookup, no subprocess. It is what an editor starts for a workspace you have opened but not trusted — a repository you are only reading should not be able to execute its own pinned plugins through your editor.

fmt

letsgo fmt                # format letsgo.mod in place
letsgo fmt path/to.mod    # a named file
letsgo fmt -              # stdin to stdout

- is what makes an editor's format-on-save work without a temporary file, and it exits 1 on a parse error rather than emitting something it guessed at.

Machine-readable output

--json is available on plan, verify, tag, features and plugin list. Every one carries schema, and removing a field bumps it:

{"schema": 1, "...": "..."}

That is the contract a tool can build on. The rendered text output is for people and is not a stable interface.

The VS Code extension

letsgo-vscode is a thin client over the binary. It needs letsgo on PATH, or pointed at with letsgo.path.

A letsgo view in the Explorer sidebar, one entry per module — a directory with a letsgo.mod — built from plan --json: resolved values, gates with their status, the artifacts a release would produce, features that depart from their defaults, and plugin pins. The status bar shows the current module's version and gate-failure count.

Update pin — a lightbulb on a plugin <hook> <command> <version> sha256:... line installs that plugin's latest release into the store and rewrites the pin.

Tag next version — asks letsgo for a proposal (tag --json), shows major/minor/patch with the proposed level first and its reason, tags on your pick, then offers to push. Pushing the tag is what starts the release in CI; the extension never publishes one itself.

Manifests — a letsgo.json gets a Verify lens, and "Reopen Editor With... → letsgo manifest" shows its artifacts, gates, features and plugins with a Verify button.

Commands, all running the binary on your machine:

Command	Runs
Plan with analysis	letsgo plan --json --analyse
Build snapshot	letsgo build --snapshot
Rehearse release	letsgo release --snapshot
Diff releases	letsgo diff <from> [to]
Install pinned plugins	letsgo plugin install
Update letsgo	letsgo update, after showing what is available and asking

Tasks — a letsgo task type with a $letsgo problem matcher for letsgo.mod:L:C: message lines:

{ "type": "letsgo", "command": "plan", "args": ["--analyse"], "problemMatcher": "$letsgo" }

It runs plan, build, verify, diff, doctor, features, audit and plugin, plus release only with --snapshot.

Untrusted workspaces

The extension never runs plan, tasks or plugins, and starts the server with --restricted. Update pin and Tag next version are not offered.

Older letsgo

The extension checks letsgo version and switches off what a too-old binary lacks, naming them once rather than erroring repeatedly: the panel, Tag and Verify need 0.29.0, Install pinned plugins 0.29.0, language features 0.30.0, and Update pin 0.31.0. A dev build is assumed current.

The extension publishes no releases and stores no tokens.