A lightweight TOML formatter that aligns values and provides optional indentation for improved readability.

I wanted pretty TOML. I wanted Go.

go-pretty-toml is a command-line utility that formats TOML files with consistent alignment and optional indentation. It preserves all data values while making your configuration files more readable and maintainable, but does not preserve comments.

Key features:

• Aligns values for clean, readable formatting
• Optional two-space indentation
• Sorts keys alphabetically
• Preserves data types
• Handles nested tables and array tables properly
• In-place file editing or stdout output

go install github.com/esacteksab/go-pretty-toml@latest

Format a file and print to stdout:

toml-fmt config.toml

Format a file with indentation:

toml-fmt -i config.toml

Format a file in-place (overwrite original):

toml-fmt -w config.toml

Format from stdin:

cat config.toml | toml-fmt

• -w, --write: Write result back to source file instead of stdout
• -i, --indent: Indent output using two spaces
• -h, --help: Show help

# This is a TOML document

title = "TOML Example"

[owner]
name = "Tom Preston-Werner"
dob = 1979-05-27T07:32:00-08:00

[database]
enabled = true
ports = [ 8000, 8001, 8002 ]
data = [ ["delta", "phi"], [3.14] ]
temp_targets = { cpu = 79.5, case = 72.0 }

[servers]

[servers.alpha]
ip = "10.0.0.1"
role = "frontend"

[servers.beta]
ip = "10.0.0.2"
role = "backend"

title = "TOML Example"

[database]
data    = [["delta", "phi"], [3.14]]
enabled = true
ports   = [8000, 8001, 8002]

[database.temp_targets]
case = 72
cpu  = 79.5

[owner]
dob  = 1979-05-27T07:32:00-08:00
name = "Tom Preston-Werner"

[servers]

[servers.alpha]
ip   = "10.0.0.1"
role = "frontend"

[servers.beta]
ip   = "10.0.0.2"
role = "backend"

title = "TOML Example"

[database]
  data    = [["delta", "phi"], [3.14]]
  enabled = true
  ports   = [8000, 8001, 8002]

  [database.temp_targets]
    case = 72
    cpu  = 79.5

[owner]
  dob  = 1979-05-27T07:32:00-08:00
  name = "Tom Preston-Werner"

[servers]

  [servers.alpha]
    ip   = "10.0.0.1"
    role = "frontend"

  [servers.beta]
    ip   = "10.0.0.2"
    role = "backend"

The formatter:

1. Parses TOML into a structured map
2. Categorizes keys into simple key-value pairs, tables, and array tables
3. Sorts keys alphabetically within each category
4. Formats each section with proper alignment and indentation
5. Writes the formatted output

go-pretty-toml can be integrated into your CI/CD pipeline to enforce consistent TOML formatting. For example, with GitHub Actions:

- name: Format TOML files
  run: |
    go install github.com/esacteksab/go-pretty-toml@latest
    find . -name "*.toml" -exec toml-fmt -w -i {} \;

MIT License