Diaryx Plugin SDK

The official SDK for building Diaryx Extism WASM plugins.

This crate replaces the per-plugin boilerplate: protocol types, host function wrappers, getrandom shims, and state management helpers. Depend on this instead of copy-pasting host_bridge.rs and protocol structs.

Quick Start

[package]
name = "diaryx_myplugin_extism"
version = "0.1.0"
edition = "2024"

[lib]
crate-type = ["cdylib"]

[dependencies]
diaryx_plugin_sdk = { version = "0.1", features = ["full"] }
extism-pdk = "1.4"
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"

use diaryx_plugin_sdk::prelude::*;
use extism_pdk::*;

#[plugin_fn]
pub fn manifest(_input: String) -> FnResult<String> {
    let manifest = GuestManifest {
        protocol_version: CURRENT_PROTOCOL_VERSION,
        id: "diaryx.myplugin".into(),
        name: "My Plugin".into(),
        version: env!("CARGO_PKG_VERSION").into(),
        description: "Does cool things".into(),
        capabilities: vec!["custom_commands".into()],
        ui: vec![],
        commands: vec!["my-command".into()],
        cli: vec![],
        requested_permissions: None,
    };
    Ok(serde_json::to_string(&manifest)?)
}

#[plugin_fn]
pub fn handle_command(input: String) -> FnResult<String> {
    let req: CommandRequest = serde_json::from_str(&input)?;
    let resp = match req.command.as_str() {
        "my-command" => {
            let content = host::fs::read_file("index.md")?;
            CommandResponse::ok(serde_json::json!({ "length": content.len() }))
        }
        _ => CommandResponse::err(format!("Unknown command: {}", req.command)),
    };
    Ok(serde_json::to_string(&resp)?)
}

#[plugin_fn]
pub fn on_event(_input: String) -> FnResult<String> {
    Ok(String::new())
}

#[plugin_fn]
pub fn get_config(_input: String) -> FnResult<String> {
    Ok("{}".into())
}

#[plugin_fn]
pub fn set_config(_input: String) -> FnResult<String> {
    Ok(String::new())
}

Feature Flags