This directory contains a number of different data files used to help support connecting via Bedrock Edition clients (including Java => Bedrock remapping).

block_states.nbt
- mined from BDS (file hosted at pmmp/BedrockData, canonical_block_states.nbt)
- Provides a listing of all blocks and block states that exist in Bedrock. Used to build a mapping from Java block states to Bedrock ones by matching (string) identifiers and data components.
blocks.nbt
- downloaded from GeyserMC/mappings
- Defines the exact Bedrock block identifier and property mappings for every Java Edition block state ID. Used in code generation to translate Java block states to Bedrock counterparts.
item_components.nbt
- mined from BDS (file hosted at CloudburstMC/Data)
runtime_item_states.nbt
- mined from BDS (file hosted at CloudburstMC/Data)
item_data_overrides.json
- adapted from GeyserMC/mappings items.json.
- Strips everything except the bedrock_data field (making it the value of each corresponding top-level key), omitting any 0 values.
- Most of items.json is automatically generated, but that value appears to be manually maintained by the Geyser team. We separate that out for our own use, while keeping the rest generated.