YAML vs TOML: Converting Between Configuration Formats

YAML vs TOML: A Quick Comparison

Both YAML and TOML are human-readable config formats, but they target different use cases:

Converting YAML to TOML

# config.yaml
server:
  host: "0.0.0.0"
  port: 8080
features:
  - auth
  - rate_limiting

# config.toml
[server]
host = "0.0.0.0"
port = 8080

features = ["auth", "rate_limiting"]

API Usage

curl -X POST https://api.toolkitapi.io/v1/convert/yaml-to-toml \
  -H "X-API-Key: $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"yaml": "key: value\nnested:\n  a: 1"}'

When Conversion Fails

TOML does not support all YAML features. Conversions fail when:

• Keys contain dots (. is a TOML path separator)
• Mixed-type arrays (TOML requires homogeneous arrays)
• Complex YAML anchors/aliases

The API returns a descriptive error for each case so you can resolve the incompatibility before retrying.

Automating Config Migrations

When migrating a project from YAML to TOML (e.g., moving from Kubernetes Helm values to a Rust application's config), run the conversion API over your config directory:

from pathlib import Path
import httpx

for yaml_file in Path("config").glob("*.yaml"):
    resp = httpx.post(
        "https://api.toolkitapi.io/v1/convert/yaml-to-toml",
        headers={"X-API-Key": API_KEY},
        json={"yaml": yaml_file.read_text()},
    )
    toml_path = yaml_file.with_suffix(".toml")
    toml_path.write_text(resp.json()["toml"])
    print(f"Converted {yaml_file} → {toml_path}")