Configuration

Discovery and the complete yamark.toml schema.

Yamark discovers yamark.toml from each formatted file’s directory upward. It uses only the nearest file; it does not merge ancestor configs.

Pass --config path/to/yamark.toml to use one explicit file for every selected path instead. Unknown keys and invalid values are errors.

The top-level tables are [format], [template], [embedded], and [paths].

[format]

[format]
wrap = "sentence:88"
compact = true
markdown_horizontal_rule = "***"

Key	Type and values	Effect when present
wrap	String: none, paragraph, sentence, sentence:<n>, or a positive integer.	Sets Markdown wrapping. An explicit --wrap value overrides it.
compact	Boolean.	Enables or disables eligible YAML block-to-flow compaction. --compact still enables compact mode when this is false.
markdown_horizontal_rule	String: "---" or "***".	Chooses the marker Yamark emits for normalized Markdown horizontal rules.

See Formatting settings for built-in defaults and the other surfaces that expose these behaviors.

[template]

Template delimiters mark regions Yamark must preserve because rendering can change the host language. The defaults are { }, {% %}, {# #}, and <% %>.

Key	Type	Effect
add_delimiters	Array of { open, close } tables.	Appends to the delimiters active at this layer, after replace_delimiters if both keys are present.
replace_delimiters	Array of { open, close } tables.	Replaces the delimiters active at this layer before any additions.

Add a delimiter pair:

[template]
add_delimiters = [
  { open = "<<", close = ">>" }
]

Replace the defaults:

[template]
replace_delimiters = [
  { open = "[[", close = "]]" }
]

Every entry must contain non-empty open and close strings.

[embedded]

Each child table maps a directive or fence name to a formatter that reads stdin and writes stdout. It accepts exactly one key: the required formatter key.

[embedded.python]
formatter = "ruff"

[embedded.r]
formatter = "air"

[embedded.sql]
formatter = { command = ["sqlfmt", "--filename", "{path}"], path_suffix = ".sql" }

formatter accepts either a built-in shorthand or a custom formatter table. Built-in shorthands are:

• ruff
• air
• mdformat
• prettier-json, prettier-jsonc, and prettier-json5
• prettier-graphql
• prettier-css, prettier-scss, prettier-less, and prettier-postcss
• prettier-html
• prettier-js, prettier-jsx, prettier-ts, and prettier-tsx

A custom formatter table requires both command and path_suffix and accepts no other keys:

Key	Requirement
command	A non-empty argv array of strings. It is not a shell command. At least one complete argv item must be {path}.
path_suffix	A non-empty suffix appended to the synthetic path passed to the formatter.

{path} cannot be embedded inside another argv item.

Built-in formatters are optional. A configured formatter is also optional when its command’s first argv item is exactly ruff, air, mdformat, or prettier. For either kind, a missing executable or nonzero exit preserves the target and emits a note only with --diagnostics. Any other configured formatter treats either condition as an error. A successful process that writes to stderr is always an error.

Embedded formatter names must be non-empty and trimmed. skip, skip file, off, on, and table are reserved directive names.

[paths]

Path keys are relative to the directory containing yamark.toml. They must not be empty or absolute and must not contain ...

[paths."docs".template]
add_delimiters = [
  { open = "<<", close = ">>" }
]

[paths."prompts".embedded_markdown.template]
add_delimiters = [
  { open = "[[", close = "]]" }
]

Table	Effect
paths.<path>.template	Adds or replaces generic template delimiters for matching files.
paths.<path>.embedded_markdown.template	Adds or replaces delimiters only for Markdown embedded in source strings or comments.

Both template tables accept add_delimiters and replace_delimiters with the same entry schema as top-level [template]. Yamark starts with the top-level delimiters, then applies matching path layers from the shallowest path to the deepest. Each replace_delimiters discards delimiters accumulated by earlier layers before that layer’s add_delimiters are appended.

Configured embedded-Markdown delimiters do not apply inside Python f-strings. Those strings preserve Python {...} expressions instead.