COI Client Payload Reference for All Network Channels

import org.bukkit.entity.Player;
import org.bukkit.plugin.messaging.PluginMessageListener;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;

public class AbilityUseListener implements PluginMessageListener {

    private final CirclePlugin plugin;

    public AbilityUseListener(CirclePlugin plugin) {
        this.plugin = plugin;
    }

    @Override
    public void onPluginMessageReceived(String channel, Player player, byte[] message) {
        if (!channel.equals("coi-client:use")) return;

        try (DataInputStream in = new DataInputStream(new ByteArrayInputStream(message))) {
            // Read the length-prefixed UTF-8 string
            String abilityId = readString(in);

            // Look up and execute the ability server-side
            plugin.getAbilityManager().executeAbility(player, abilityId);

        } catch (Exception e) {
            plugin.getLogger().warning("Failed to parse coi-client:use from " + player.getName());
        }
    }

    /** Mirrors Minecraft's length-prefixed UTF-8 string encoding. */
    private String readString(DataInputStream in) throws Exception {
        int length = readVarInt(in);
        byte[] bytes = new byte[length];
        in.readFully(bytes);
        return new String(bytes, java.nio.charset.StandardCharsets.UTF_8);
    }

    private int readVarInt(DataInputStream in) throws Exception {
        int result = 0, shift = 0;
        byte b;
        do {
            b = in.readByte();
            result |= (b & 0x7F) << shift;
            shift += 7;
        } while ((b & 0x80) != 0);
        return result;
    }
}

@Override
public void onPluginMessageReceived(String channel, Player player, byte[] message) {
    if (!channel.equals("coi-client:request")) return;

    // Build and send the abilities list back to this player
    plugin.getAbilityManager().sendAbilitiesToPlayer(player);
}

id|localizedName|englishName|category

sun-9-0|Пісня барда|bard-song|music;fool-1-0|Жарт|jest|trickery

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.nio.charset.StandardCharsets;

public void sendAbilitiesToPlayer(Player player) {
    // Build semicolon-separated ability records
    StringBuilder sb = new StringBuilder();
    for (Ability ability : getAbilitiesForPlayer(player)) {
        if (sb.length() > 0) sb.append(';');
        sb.append(ability.getId())
          .append('|').append(ability.getLocalizedName())
          .append('|').append(ability.getEnglishName())
          .append('|').append(ability.getCategory());
    }

    byte[] payload = writeString(sb.toString());
    player.sendPluginMessage(plugin, "coi-client:abilities", payload);
}

/** Encodes a String as a Minecraft-style length-prefixed UTF-8 byte array. */
private byte[] writeString(String value) throws RuntimeException {
    try {
        byte[] strBytes = value.getBytes(StandardCharsets.UTF_8);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream out = new DataOutputStream(baos);
        writeVarInt(out, strBytes.length);
        out.write(strBytes);
        return baos.toByteArray();
    } catch (Exception e) {
        throw new RuntimeException("Failed to encode string payload", e);
    }
}

private void writeVarInt(DataOutputStream out, int value) throws Exception {
    while ((value & ~0x7F) != 0) {
        out.writeByte((value & 0x7F) | 0x80);
        value >>>= 7;
    }
    out.writeByte(value);
}

public void sendCooldown(Player player, String abilityId, int ticks) {
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream out = new DataOutputStream(baos);

        byte[] idBytes = abilityId.getBytes(StandardCharsets.UTF_8);
        writeVarInt(out, idBytes.length);
        out.write(idBytes);
        out.writeInt(ticks); // big-endian 32-bit int

        player.sendPluginMessage(plugin, "coi-client:cooldown", baos.toByteArray());
    } catch (Exception e) {
        plugin.getLogger().warning("Failed to send cooldown payload: " + e.getMessage());
    }
}

// Example: put "sun-9-0" on a 5-second cooldown
sendCooldown(player, "sun-9-0", 100);

/**
 * Sends a visual effect payload to a player.
 *
 * @param player   the target player
 * @param effectId registered effect name, or "all"
 * @param params   key=value pairs (comma-separated), or "stop"
 */
public void sendEffect(Player player, String effectId, String params) {
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream out = new DataOutputStream(baos);

        writeUtf(out, effectId);
        writeUtf(out, params);

        player.sendPluginMessage(plugin, "coi-client:effect", baos.toByteArray());
    } catch (Exception e) {
        plugin.getLogger().warning("Failed to send effect payload: " + e.getMessage());
    }
}

// Examples
sendEffect(player, "cracks",    "intensity=0.8,pulse=true,duration=8000");
sendEffect(player, "eyes",      "count=3");
sendEffect(player, "vignette",  "color=red,intensity=0.5");
sendEffect(player, "cracks",    "stop");   // stop just cracks
sendEffect(player, "all",       "stop");   // clear all active effects

public void applyMythicalForm(Player target, String pathway, int tier, boolean start) {
    try {
        String uuid = target.getUniqueId().toString();
        String action = start ? "start" : "stop";
        String params = pathway + ":" + tier + ":" + action;

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream out = new DataOutputStream(baos);

        writeUtf(out, uuid);
        writeUtf(out, params);

        // Broadcast to all online players so they all see the transformation
        for (Player viewer : plugin.getServer().getOnlinePlayers()) {
            viewer.sendPluginMessage(plugin, "coi-client:mythical", baos.toByteArray());
        }
    } catch (Exception e) {
        plugin.getLogger().warning("Failed to send mythical form payload: " + e.getMessage());
    }
}

// Example: apply the Fool pathway tier-1 form
applyMythicalForm(player, "fool", 1, true);

// Example: remove it
applyMythicalForm(player, "fool", 1, false);

madness=0.35;permanentMadness=0.1;freezeStacks=2;mentalPressure=15;tiredness=0.6

public void syncConditions(Player player, double madness, double permMadness,
                            int freeze, int pressure, double tiredness) {
    String data = "madness=" + madness
            + ";permanentMadness=" + permMadness
            + ";freezeStacks=" + freeze
            + ";mentalPressure=" + pressure
            + ";tiredness=" + tiredness;

    byte[] payload = writeString(data);
    player.sendPluginMessage(plugin, "coi-client:conditions", payload);
}

// Example: update a player who just gained some madness
syncConditions(player, 0.35, 0.10, 2, 15, 0.60);