Building Plugins

SDK setup

Tundra plugins are WebAssembly components targeting wasm32-wasip2. The SDK provides WIT bindings for all host capabilities.

cargo new --lib my-tundra-plugin
cd my-tundra-plugin

Cargo.toml:

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

[dependencies]
tundra-plugin-sdk = "1.0"
wit-bindgen = "0.36"

Plugin manifest

Create tundra-plugin.toml:

[plugin]
id          = "com.example.my-plugin"
name        = "My Plugin"
version     = "1.0.0"
description = "Does something useful"
author      = "Your Name <you@example.com>"
license     = "MIT"

[capabilities]
http_outbound = ["api.example.com"]   # allowlisted domains
kv_read       = true
kv_write      = true
events_publish = true

[hooks]
on_deployment_complete = "handle_deployment"   # exported function name

Writing a plugin

use tundra_plugin_sdk::prelude::*;

// Called by Tundra when a deployment completes
#[tundra_hook]
fn handle_deployment(ctx: DeploymentContext) -> Result<()> {
    let site = ctx.site();

    // Write to plugin kv store
    tundra_sdk::kv::set("last_deploy", &site.id)?;

    // Make an outbound HTTP request (must be in capabilities allowlist)
    let resp = tundra_sdk::http::post(
        "https://api.example.com/webhook",
        &json!({ "site": site.id, "status": "deployed" }),
    )?;

    tundra_sdk::audit::log("deployment.notified", &site.id)?;
    Ok(())
}

Building

# Install the wasm target
rustup target add wasm32-wasip2

# Build
cargo build --release --target wasm32-wasip2

# The plugin is at target/wasm32-wasip2/release/my_tundra_plugin.wasm

Testing locally

# Install the Tundra plugin dev runner
cargo install tundra-plugin-dev

# Run against a local Tundra instance
tundra-plugin-dev run \
  --plugin target/wasm32-wasip2/release/my_tundra_plugin.wasm \
  --tundra-url http://localhost:7400 \
  --token tnd_dev_<token>

WIT contracts

The full WIT interface definitions are in tundra-plugin-sdk/wit/:

Interface	What it exposes
`tundra:plugin/http`	Outbound HTTP with allowlist enforcement
`tundra:plugin/kv`	Isolated key-value store
`tundra:plugin/events`	Publish events to tundrad
`tundra:plugin/audit`	Write audit log entries
`tundra:plugin/sites`	Read site metadata
`tundra:plugin/deployments`	Trigger deployments