Overview

Serverless compute that scales to zero, triggered by HTTP, queues, storage events, or cron.

Function provides event-driven, stateless compute. Functions handle HTTP requests, process queue messages, react to storage events, or run on a schedule. They scale automatically with load and scale to zero when idle.

Platform Mapping

Platform	Backing Service	Provisioned by
AWS	AWS Lambda (ARM64/Graviton)	Alien
GCP	Google Cloud Run	Alien
Azure	Azure Container Apps	Alien

When to Use

Use Function for event-driven, stateless compute — HTTP APIs, webhook handlers, background processors, queue consumers, scheduled tasks.

Don't use Function for long-running stateful workloads, persistent WebSocket connections, or services that need internal DNS discovery.

Quick Start

// alien.ts
const api = new alien.Function("api")
  .code({ type: "source", src: "./api", toolchain: { type: "typescript" } })
  .ingress("public")
  .permissions("execution")
  .build()

Ingress

Controls how the function is accessible over the network.

Mode	Description
`"public"`	Gets an HTTPS endpoint. For APIs, webhooks, internal tools. See External URLs.
`"private"`	No HTTP endpoint. Only reachable via triggers or direct invocation. Default.
`"vpc"`	Accessible within the VPC only. Requires network configuration.

Function-to-Function Invocation

Functions can call other functions directly — low-latency internal calls that bypass public endpoints:

import { func } from "@alienplatform/sdk"

const processor = await func("image-processor")
const result = await processor.invokeJson("resize", { imageUrl: "...", width: 800 })
const url = await processor.getUrl()  // public URL, if available

let processor = ctx.bindings().load_function("image-processor").await?;
let response = processor.invoke(FunctionInvokeRequest {
    target_function: "image-processor".to_string(),
    method: "POST".to_string(),
    path: "/resize".to_string(),
    headers: BTreeMap::new(),
    body: serde_json::to_vec(&payload)?,
    timeout: Some(Duration::from_secs(30)),
}).await?;

Configuration

Method	Default	Description
`.code(code)`	required	Source code or pre-built image. See Toolchains.
`.ingress("public" \| "private" \| "vpc")`	`"private"`	Network accessibility. See Ingress above.
`.memoryMb(number)`	`256`	Memory allocation. 128–32,768 MB.
`.timeoutSeconds(number)`	`180`	Max execution time. 1–3,600 seconds.
`.concurrencyLimit(number)`	platform default	Max concurrent executions. Maps to reserved concurrency (Lambda), max instances (Cloud Run), or max replicas (Container Apps).
`.commandsEnabled(boolean)`	`false`	Enable the remote command protocol.
`.readinessProbe({ method, path })`	—	Health check after deploy. Only for `"public"` ingress.
`.environment(Record)`	`{}`	Environment variables.
`.link(resource)`	—	Connect to a resource for binding access. Can be called multiple times.
`.trigger(trigger)`	—	Add an event trigger. Can be called multiple times.
`.permissions(string)`	required	Permission profile name.

Triggers

// Queue trigger — one message per invocation
const worker = new alien.Function("worker").trigger(tasks).build()

// In function code:
import { onQueueMessage, onStorageEvent } from "@alienplatform/sdk"

onQueueMessage("tasks", async (msg) => { /* ... */ })
onStorageEvent("uploads", async (event) => { /* ... */ })