TL Schema Merger

Merges the Telegram API TL schema files from tdlib and tdesktop into a single unified superset.

Why

Both tdlib and tdesktop maintain their own copy of the Telegram API schema. They are nearly identical but can differ in edge cases — one may add new constructors before the other, or carry internal-only definitions. This tool produces a merged schema that includes everything from both sources.

How it works

1. Downloads (or reads) both .tl files
2. Parses every combinator definition, keyed by name#crc
3. Skips the tdlib preamble (built-in type aliases, internal types, invokeWith*Prefix variants, test functions)
4. Merges using CRC32 as the ground truth:
   • Same name + same CRC — identical definition, keep one
   • Same name + different CRC — conflict, auto-select the version with more parameters
   • Name only in one source — include it
   • Same CRC + different name — alias (e.g. Prefix variant), skip
5. Outputs the merged schema using tdesktop's structure as the skeleton, preserving the // LAYER marker

Usage

No external dependencies — pure Python standard library.

# Download from GitHub and merge (default)
python main.py

# Specify output file
python main.py -o output.tl

# Use local files
python main.py --tdlib path/to/telegram_api.tl --tdesktop path/to/api.tl

# Only show differences, don't write output
python main.py --diff-only

Automated releases

A GitHub Actions workflow runs daily at 08:00 CST (00:00 UTC). It downloads the latest schemas, runs the merge, and — if the result differs from the previous version — commits the updated merged.tl and creates a GitHub release tagged layer-{N}.

License

Unlicense — public domain.