Host calls

Packets and plugin channels

Sending raw packets and plugin-channel messages, and decoding and encoding packet bodies.

Generated by tools/gen_api_docs.py; do not edit by hand. See host calls for how a call is made and how values are encoded. Each example shows the shape of a Wasm request with its required fields; the values in it are illustrative.

send_payload

fn send_payload(player: PlayerId, channel: &str, data: &[u8]) -> bool

Sends a message on a plugin channel.

Returns whether it went. false means the player has gone or the message was longer than the protocol's 32767 bytes -- and the second is not a slow message, it is a disconnect, which is why it is refused rather than split.

Wasm request

Reply: {"ok": ...} holding the Rust return value bool, encoded as in conventions.

{"call": "send_payload", "player": 7, "payload": [1, 2, 3], "channel": "example:channel"}

send_packet

fn send_packet(player: PlayerId, packet: &str, body: &[u8]) -> Result<bool, String>

Sends one player a packet, as the game would have: packet names it as its hook point does (play.clientbound.set_title_text, packet. optional) and body is its bytes -- from packet_encode, or written by hand. Play-state, clientbound packets only, and never one that changes the connection's state (start_configuration, login). False if the player is not connected. ProtocolLib's sendServerPacket.

Wasm request

Reply: {"ok": ...} holding the Rust return value Result<bool, String>, encoded as in conventions. An Err arrives as {"error": "..."}.

{"call": "send_packet", "player": 7, "packet": "play.clientbound.block_update"}

packet_decode

fn packet_decode(packet: &str, body: &[u8]) -> Result<crate::Data, String>

A packet's body as its named fields (a map), for a packet this server has a schema for: ProtocolLib's PacketContainer. See packet_schemas.

Wasm request

Reply: {"ok": ...} holding the Rust return value Result<crate::Data, String>, encoded as in conventions. An Err arrives as {"error": "..."}.

{"call": "packet_decode", "packet": "play.clientbound.block_update"}

packet_encode

fn packet_encode(packet: &str, fields: &crate::Data) -> Result<Vec<u8>, String>

The other way: named fields, every one given, as the packet's bytes.

Wasm request

Shape and limits, as the router words its errors: "fields should be an object".

Reply: {"ok": ...} holding the Rust return value Result<Vec<u8>, String>, encoded as in conventions. An Err arrives as {"error": "..."}.

{"call": "packet_encode", "packet": "play.clientbound.block_update", "fields": {"at": [0, 64, 0], "state": "minecraft:glass"}}

packet_schemas

fn packet_schemas() -> crate::Data

Every packet packet_decode and packet_encode know, each with its fields and their kinds: {"play.clientbound.set_health": [["health", "float"], ...]}.

Wasm request

No fields besides call.

Reply: {"ok": ...} holding the Rust return value crate::Data, encoded as in conventions.

{"call": "packet_schemas"}

From docs/api/reference/host-calls/packets.md in the RustMC repository at bbd81209ad.