Configuration Keys

The keys Fuse reads from fuse.json or .fuserc, their discovery order, and how they combine with command-line flags.

A configuration file lets a project set fusion defaults once instead of repeating flags on every run. Fuse reads these defaults from fuse.json or .fuserc, merges them with the command-line flags, and applies built-in defaults for anything left unspecified. This page lists every supported key, where Fuse looks for the file, and how a key's value combines with a flag of the same meaning.

This page is for engineers setting project defaults and for maintainers who need the exact discovery and precedence rules. The Quickstart shows fuse init scaffolding a file in context.

Purpose And Scope

This page documents the configuration file: its discovery, its keys, and its precedence against flags. It does not document the flags themselves; each key corresponds to a flag whose full behavior is in the Options reference. All keys are optional.

Discovery

Fuse searches for a configuration file starting in the working directory and walking up through parent directories to the filesystem root. The first match wins. Within a single directory, fuse.json takes precedence over .fuserc. A file that fails to parse is ignored silently: Fuse continues as if no configuration file were present, falling back to flags and built-in defaults.

Precedence

For any setting, Fuse resolves the value in this order, highest first:

An explicit command-line flag.
The value from the discovered configuration file.
The built-in default.

An explicit flag always overrides the configuration file, and the configuration file overrides the built-in default. A key omitted from the file leaves the flag or default in effect.

Supported Keys

Key	Type	Maps to flag	Description
`directory`	string	`--directory`	Source directory to fuse.
`output`	string	`--output`	Output directory for fused files.
`name`	string	`--name`	Output file name without extension.
`format`	xml \| markdown \| json	`--format`	Output format.
`tokenizer`	string	`--tokenizer`	Tokenizer model or encoding name.
`noManifest`	bool	`--no-manifest`	Omit the manifest header when `true`.
`provenance`	bool	`--provenance`	Enable dependency inclusion provenance annotations.
`gitStats`	bool	`--git-stats`	Include git churn and last-modified statistics in the manifest.
`maxTokens`	int	`--max-tokens`	Hard token limit.
`splitTokens`	int	`--split-tokens`	Per-part split threshold in tokens.
`recursive`	bool	`--recursive`	Search subdirectories recursively.
`includeMetadata`	bool	`--include-metadata`	Include file metadata in output entries.

The full behavior, type conventions, and defaults for each corresponding flag are in the Options reference.

The Scaffold From fuse init

Running fuse init writes the following fuse.json to the current directory when one is absent:

{
  "directory": ".",
  "output": "./fuse-output",
  "format": "xml",
  "tokenizer": "o200k_base",
  "noManifest": false,
  "provenance": false
}

These values are a starting point, not a required set. Edit, remove, or add keys from the table above as needed; any key you remove falls back to its built-in default.

What This Does Not Cover

This page does not document the flags' full semantics (see Options reference), the fuse init command (see Commands), or the output formats (see Output Specification).

Continue to the Options reference for full flag semantics, or the Quickstart for fuse init in context.