TL;DR — Pulumi ESC (now GA) gives you hierarchical, dynamic-credential environments. Combined with Pulumi Deployments and the AI agent CLI helpers, your AI voice stack provisions in a single pulumi up with no static secrets anywhere.

What you'll set up

A TypeScript Pulumi program that stands up a k3s edge cluster on Hetzner, deploys a LiveKit + voice-agent + Postgres trio, and pulls all secrets at runtime from Pulumi ESC backed by AWS Secrets Manager.

Architecture

flowchart LR
  PULUMI[pulumi up] --> ESC[Pulumi ESC]
  ESC --> ASM[(AWS Secrets Manager)]
  PULUMI --> HZ[Hetzner k3s nodes]
  HZ --> LK[LiveKit Deployment]
  HZ --> AG[Voice Agent Deployment]
  HZ --> PG[Postgres StatefulSet]
  ESC -->|runtime env| AG

Step 1 — Initialize the project and ESC environment

```bash pulumi new typescript -y pulumi env init voice-prod pulumi env set voice-prod aws.login.fn::open '{"provider":"aws-secrets","login":"arn:aws:iam::123:role/pulumi-esc"}' pulumi env set voice-prod openai.apiKey '{"fn::secret":{"fn::open::aws-secrets":"openai/realtime"}}' ```

Now openai.apiKey is defined in ESC but only fetched at pulumi up time — the value never lives on disk.

Step 2 — Wire the program to ESC

```yaml

Pulumi.voice-prod.yaml

environment:

• voice-prod ```

Now every config read like config.requireSecret("openai:apiKey") resolves through ESC.

Step 3 — Provision Hetzner k3s nodes

```typescript import * as hcloud from "@pulumi/hcloud"; import * as command from "@pulumi/command"; import * as pulumi from "@pulumi/pulumi";

const sshKey = new hcloud.SshKey("ops", { publicKey: process.env.SSH_PUB! }); const server = new hcloud.Server("voice-edge-1", { serverType: "ccx33", // 8 vCPU AMD, dedicated image: "ubuntu-24.04", location: "ash", // Ashburn, VA — closest to OpenAI us-east sshKeys: [sshKey.id], });

const k3sInstall = new command.remote.Command("k3s-install", { connection: { host: server.ipv4Address, user: "root", privateKey: process.env.SSH_KEY! }, create: curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.31.0+k3s1 sh -s - --disable traefik, }); ```

ccx33 (dedicated AMD, 8 vCPU / 32 GB) is the sweet spot for ~50 concurrent voice sessions on OpenAI Realtime in our benchmarks.

Step 4 — Deploy the chart with the Kubernetes provider

```typescript import * as k8s from "@pulumi/kubernetes"; import { interpolate } from "@pulumi/pulumi";

const kubeconfig = command.remote.runOutput({ connection: { host: server.ipv4Address, user: "root", privateKey: process.env.SSH_KEY! }, create: "cat /etc/rancher/k3s/k3s.yaml", }, { dependsOn: k3sInstall }).apply(r => r.stdout.replace("127.0.0.1", server.ipv4Address));

const k = new k8s.Provider("k3s", { kubeconfig });

const ns = new k8s.core.v1.Namespace("voice", { metadata: { name: "voice" }}, { provider: k });

const cfg = new pulumi.Config(); const apiKey = cfg.requireSecret("openai:apiKey");

new k8s.core.v1.Secret("voice-secrets", { metadata: { namespace: ns.metadata.name, name: "voice-secrets" }, stringData: { OPENAI_API_KEY: apiKey }, }, { provider: k }); ```

apiKey is a pulumi.Output<string> that's only resolved by the engine — your TypeScript code never sees the plaintext.

Step 5 — Helm release for the agent

```typescript import * as helmv4 from "@pulumi/kubernetes/helm/v4";

new helmv4.Chart("voice-agent", { chart: "oci://ghcr.io/acme/charts/voice-agent", version: "1.0.0", namespace: ns.metadata.name, values: { image: { repository: "ghcr.io/acme/voice-agent", tag: process.env.GIT_SHA }, livekit: { url: "ws://voice-livekit:7880" }, openai: { secretRef: "voice-secrets" }, }, }, { provider: k }); ```

Helm v4 provider in Pulumi (released 2025) does server-side apply and reports kstatus-aware readiness.

Step 6 — Pulumi Deployments for review stacks

```yaml

.pulumi/Pulumi.yaml -> deployment block

template: config: aws:region: { value: us-east-1 } deploymentSettings: sourceContext: { git: { repoURL: "https://github.com/acme/voice", branch: main } } operationContext: { preRunCommands: ["uv sync --frozen"] } ```

Now every PR gets a pulumi preview posted as a comment, and merging main triggers pulumi up — Pulumi-managed runners, no GH Actions runner needed.

Step 7 — Pulumi AI for one-off resources

```bash pulumi ai prompt "add a Cloudflare DNS record voice.example.com pointing to the Hetzner server" ```

In 2026 the AI agent will read your existing program, generate a coherent diff, and offer it as a PR. Useful for boilerplate; review every line for IAM and networking.

Pitfalls

• Output<string> leaks via .toString() — if you log an Output you'll get Calling .toString() on an Output<T> warning. Use .apply properly.
• ESC environment imports across stacks can cause circular references; keep your environments shallow.
• Hetzner snapshot rebuild wipes k3s state; back up etcd or use S3-snapshotter.
• uv in Pulumi Deployments — set PIP_DISABLE_PIP_VERSION_CHECK=1 and UV_NO_CACHE=1 to avoid stale wheel issues.
• Helm v4 vs v3 provider — values are not 1:1; fetchOpts becomes repositoryOpts. Migration takes ~10 min per chart.

How CallSphere does this in production

CallSphere's primary infra is k3s on a dedicated host (not Hetzner — our Postgres lives at 72.62.162.83 behind Cloudflare Tunnel) but the Pulumi pattern above runs CallSphere fork environments for partners on Hetzner ccx33 nodes. ESC pulls model keys from a central vault per partner. 37 agents, 90+ tools, 115+ DB tables, $149/$499/$1499, 14-day trial, 22% affiliate.

FAQ

Q: Pulumi vs Terraform for AI infra? Pulumi if your team writes TypeScript/Python already; the typed SDKs catch IAM bugs at compile time. Terraform if you want HCL's declarative purity.

Q: ESC vs External Secrets Operator? ESC for infra-time secrets (during pulumi up); ESO for runtime secrets (Kubernetes pods). Use both.

Q: Pulumi Deployments cost? Free for individuals; team plans start ~$50/user/month and replace a self-hosted runner.

Q: Can I import existing infra? Yes — pulumi import aws:s3/bucket:Bucket my-bucket existing-name generates the program.

Sources

• Pulumi Release Notes — Pulumi Copilot, ESC, Docker Provider
• Pulumi 2.0, Now with Superpowers
• The Past 6 Months of Pulumi Releases
• Pulumi Tutorial: IaC with TypeScript, Python & Go 2026 — env zero
• Pulumi TypeScript and Node.js docs