harn config-get

harn config-get [options] <file> <key>

Extract one value from a JSON or YAML config file by dotted-path. It’s the quick way to pull a single field — a version, a port, a nested flag — without reading the whole file or shelling out to jq. The file type is inferred from its extension (.json, .yaml, .yml).

Bracket notation handles hyphenated keys and array indices that plain dots can’t: compilerOptions.paths["@/*"][0]. Dotted and bracketed segments can be mixed freely.

Options

Flag	Description
--json	Structured JSON envelope: { file, format, key, value, type, found }.
--raw	Print the raw string value with no JSON encoding wrapper.

By default a scalar (string, number, boolean, null) prints as-is and an object or array prints as pretty JSON. A missing key exits non-zero with a key_not_found error — unless --json, which always succeeds and reports found: false.

Examples

# Top-level scalar
harn config-get package.json name

# Nested path
harn config-get config.yaml server.port

# Object value prints as pretty JSON
harn config-get tsconfig.json compilerOptions.paths

# Bracket notation for a hyphenated / glob key and an array index
harn config-get tsconfig.json 'compilerOptions.paths["@/*"][0]'

# Full envelope, including the resolved type + found flag
harn config-get package.json version --json

Notes

Both JSON and YAML are parsed into the same in-memory shape, so the same dotted-path syntax works against either format. A parse failure or an unsupported extension reports an error rather than a partial result.