autumn-plugin-discord

A Discord bot framework for Autumn apps: declare slash commands as data, mount the signed interactions webhook, and answer with typed responses. No heavyweight bot framework — just ed25519-dalek for signature verification and reqwest for REST.

Quickstart

# Cargo.toml
[dependencies]
autumn-plugin-discord = { git = "https://github.com/madmax983/autumn-plugin-discord" }

# autumn.toml
[discord]
application_id = "123456789012345678"
public_key = "<64 hex chars from the developer portal>"

export DISCORD_BOT_TOKEN="<bot token from the developer portal>"

use autumn_plugin_discord::{
    Command, CommandContext, DiscordPlugin, InteractionResponse, MessagePayload,
};
use autumn_web::prelude::*;

async fn ping(_ctx: CommandContext) -> AutumnResult<InteractionResponse> {
    Ok(InteractionResponse::channel_message(
        MessagePayload::content("Pong!"),
    ))
}

#[autumn_web::main]
async fn main() {
    autumn_web::app()
        .plugin(
            DiscordPlugin::new()
                .command(Command::new("ping", "Replies with Pong!").handler(ping)),
        )
        .run()
        .await;
}

Then, in the Discord developer portal:

Set the Interactions Endpoint URL to https://<your-host>/discord/interactions.
Register the command once: cargo run --example register_commands.
Type /ping in a server with the bot.

What the plugin installs

Piece	Detail
Config section	`[discord]` — `application_id`, `public_key`. The bot token comes only from `DISCORD_BOT_TOKEN`.
Route	`POST /discord/interactions` — verifies the Ed25519 signature, answers PINGs, dispatches slash commands.
Extractor	`VerifiedInteraction` — mount your own endpoint when `/discord/interactions` does not fit.
Health	A `"discord"` health indicator backed by `GET /applications/@me`.
REST client	`DiscordClient` — register commands, send follow-ups for deferred interactions.
Gateway	`GatewayClient` — minimal websocket client: identify, heartbeat, event dispatch. Spawn it yourself; the plugin does not auto-connect.

Deferred responses

Answer within 3 seconds, or acknowledge and follow up later:

use autumn_plugin_discord::{InteractionResponse, MessagePayload};

async fn slow(ctx: CommandContext) -> AutumnResult<InteractionResponse> {
    let token = ctx.interaction.token.clone();
    let client = ctx.client.clone();
    tokio::spawn(async move {
        // ... long work ...
        let _ = client
            .create_followup(&token, &MessagePayload::content("Done!"))
            .await;
    });
    Ok(InteractionResponse::deferred())
}

Crate layout

Module	Purpose
`config`	Layered `[discord]` config: file, env, builder overrides
`commands`	Slash-command declarations (`Command`), the `CommandRegistry`, dispatch
`interactions`	The webhook route and the `VerifiedInteraction` extractor
`verify`	Ed25519 signature verification (`X-Signature-Ed25519` / `X-Signature-Timestamp`)
`client`	Discord REST client
`gateway`	Minimal gateway client (feature `gateway`, on by default)
`health`	`GET /applications/@me` readiness check
`plugin`	`DiscordPlugin` (`::new()`, `.command()`, `.configure()`) and `DiscordRuntime`
`error`	`Error` + `ErrorKind` + mapping to HTTP status codes

Docs and comments

Written in ASD-STE100 style: short sentences, active voice, simple present tense.

Known issues

The gateway client does not resume sessions. A dropped connection reconnects with a fresh Identify. Bots that need resume should extend gateway.rs or bring their own client.
register_commands overwrites global commands. Global commands take up to an hour to propagate; guild-scoped registration is not wrapped yet.

Build status

All three quality gates pass as of 2026-09-29:

cargo fmt --all -- --check        # clean
cargo clippy --locked --all-targets --all-features -- -D warnings  # clean
cargo test --locked --all-targets --all-features    # 50 passed, 0 failed

License

Apache-2.0. See LICENSE.

autumn-plugin-discord 0.3.0