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fallow type-aware: check the TypeScript companion

Check that the optional fallow-type-aware companion is installed and compatible before you use --type-aware. The status command does not analyze the project.

fallow type-aware inspects the optional TypeScript semantic companion, fallow-type-aware. The --type-aware flag of dead-code, fix, health, and other commands uses this companion. For what type-aware mode does, see Type-aware TypeScript analysis.

The command has one subcommand, status.

`type-aware status`

Reports if the companion is available and compatible with this fallow build. It does not load or analyze the project, and it does not read the config file.

fallow type-aware status
fallow type-aware status --format json --quiet

The human output is one line:

[OK] Type-aware companion: available (3.40.0, protocol 7, TypeScript 7.0.2)

When the companion is not available, the output says so and gives an Action: line with the fix, for example the npm install command for the matching companion version.

The JSON output has kind: "type-aware-status":

{
  "kind": "type-aware-status",
  "schema_version": 8,
  "version": "3.40.0",
  "available": true,
  "discovery_source": "npm-wrapper",
  "companion_path": "fallow-type-aware.mjs",
  "package_version": "3.40.0",
  "protocol_version": 7,
  "backend_family": "typescript-go",
  "backend_version": "7.0.2",
  "remediation": null
}

Field	Meaning
`available`	`true` only when fallow found the companion, its package and protocol versions match this fallow build, and its backend version is in the supported range.
`discovery_source`	How fallow found the companion: `installed-sibling`, `environment-override` (you set `FALLOW_TYPE_AWARE_BIN`), or a launcher marker such as `npm-wrapper` or `github-action`. `null` when discovery failed.
`companion_path`	The companion path, relative to the project root when it is inside the root. Otherwise only the file name.
`package_version`	The `fallow-type-aware` package version that the companion reported.
`protocol_version`	The protocol version of the companion. When the companion did not answer, the version that this fallow build uses.
`backend_family`, `backend_version`	The TypeScript checker backend and its version, for example `typescript-go`. Set `FALLOW_TYPE_AWARE_BACKEND=tsrs` to select the experimental tsrs backend.
`remediation`	The fix when `available` is `false`, otherwise `null`.

Run the command in the same environment as the surface that you check, for example the CI job or the MCP server process. The backend and the companion path come from environment variables.

type-aware status exits 0 also when the companion is not available. Read available to decide. It accepts only human and json output. Other formats exit with code 2.

Options

fallow type-aware status has no flags of its own. It accepts the global flags, for example --root, --format, and --quiet.