100xprompt formats every file it edits, the moment the change lands. It runs your project’s formatter over the file automatically, so the code it writes matches your existing style without you asking - consistent indentation, quotes, and import ordering on every change. Hand-formatting agent output wastes your time and muddies diffs. 100xprompt does it for you, then reads the result before it moves on.

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How formatting works

Formatting runs as part of every edit. After 100xprompt writes a change to disk, it formats the file in place, then re-reads it to check for problems. Type errors, lint issues, and unresolved imports come back into the conversation so 100xprompt can fix them in the same turn.
Formatting only runs for file types that have a matching, available formatter. If nothing matches the file’s extension, the change is left exactly as written.

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Use a built-in formatter

100xprompt ships with support for a wide range of formatters out of the box. Each one activates automatically when 100xprompt detects that it applies to your project - either because the tool is installed and on your PATH, or because your project carries the relevant dependency or config file (for example a biome.json, a .clang-format, or prettier in your package.json).
FormatterLanguages / files
prettierJS/TS, JSX/TSX, HTML, CSS/SCSS/Sass/Less, Vue, Svelte, JSON/JSONC, YAML, TOML, XML, Markdown/MDX, GraphQL
biomeJS/TS, JSX/TSX, HTML, CSS, JSON, YAML, Markdown, GraphQL and more
gofmtGo
rustfmt / cargofmtRust
ruff / uv formatPython
clang-formatC, C++, and Arduino (.ino) sources and headers
zigZig
ktlintKotlin
rubocop / standardrbRuby
htmlbeautifierERB templates
dartDart
mixElixir
ocamlformatOCaml
terraformTerraform (.tf, .tfvars)
gleamGleam
shfmtShell scripts
nixfmtNix
latexindentLaTeX
airR
Tips:
  • You don’t need to configure any of these. Add the formatter your project already uses, and 100xprompt picks it up on the next edit.
  • Keep the formatter on your PATH, or its config file in the project, so 100xprompt can detect it.

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Configure the formatter option

Use the formatter key in your 100xprompt.json to customize which formatters run, to register a formatter of your own, or to turn formatting off entirely.

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Disable a single formatter

Suppose a built-in formatter conflicts with a step in your own toolchain. Set disabled: true on it to stop 100xprompt from ever running it:
100xprompt.json
{
  "$schema": "https://100xprompt.com/config.json",
  "formatter": {
    "prettier": {
      "disabled": true
    }
  }
}

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Disable all formatting

Set formatter to false to skip formatting after edits across the board:
100xprompt.json
{
  "$schema": "https://100xprompt.com/config.json",
  "formatter": false
}

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Add or override a formatter

Define your own entry to register a new formatter or replace the command of a built-in one. Each entry accepts these fields:
FieldTypeDescription
commandstring[]The command to run. Use the $FILE placeholder for the path of the file being formatted.
extensionsstring[]File extensions this formatter applies to (for example [".py"]).
environmentobjectExtra environment variables to set when the command runs.
disabledbooleanSet to true to turn this formatter off.
100xprompt.json
{
  "$schema": "https://100xprompt.com/config.json",
  "formatter": {
    "custom-python": {
      "command": ["black", "$FILE"],
      "extensions": [".py"],
      "environment": {
        "BLACK_CACHE_DIR": ".cache/black"
      }
    }
  }
}
When you define your own entry, 100xprompt runs it whenever it edits a matching file - it does not check for a config file or dependency first, so make sure the command is available in your environment.
A custom command runs exactly as written against the edited file. Only register commands you trust, and prefer in-place formatters that edit the file at $FILE directly.
  • Code Editing: how 100xprompt reads, edits, and verifies changes across your codebase.
  • Settings: the full set of 100xprompt.json options and how configuration is resolved.

Code Editing

How 100xprompt reads, edits, and verifies changes across your codebase.

Settings

The full set of 100xprompt.json options and how configuration is resolved.