Getting Started

CCL (Categorical Configuration Language) is a minimal configuration format built around a single idea: every configuration is a list of key = value pairs, and every value is just a string. Indentation creates structure, and structured values are recursively parsed as CCL.

That’s the whole language. Everything else — typed accessors, dotted-key flattening, list helpers, comment conventions — is convenience built on top.

What CCL Looks Like

/= A small CCL document
name = My Application
version = 1.0.0

server =
  host = 0.0.0.0
  port = 8080

allowed origins =
  = https://example.com
  = https://www.example.com

A few things to notice:

• Keys and values are split on the first =. Both are trimmed of surrounding whitespace.
• Indented lines under server = are the value of server, and that value is itself a CCL document.
• An empty key (= value) is how you write list items.
• Comments start with /= at the beginning of a line.

There are no quoting rules, no type system, and no special characters to escape. What you write is what you get.

Where to Go Next

CCL has four audiences and a doc section for each:

• You want to write CCL configs → Writing CCL walks through every construct with examples, then CCL Examples shows real-world patterns.
• You want a quick syntax lookup → CCL Syntax Reference is the one-page cheat sheet, including edge cases.
• You want to implement a CCL parser → Implementing CCL covers the core requirements, and Parsing Algorithm details the recursive fixed-point approach.
• You’re an AI assistant helping with CCL → AI Assistant Quickstart is the single-page orientation tuned for that use.

If you’re stuck on a specific question, the FAQ covers the most common confusions, and Dotted Keys Explained addresses the most common surprise.