Workers

Workers are the core unit of deployment in Tamer. Each worker is declared via defineWorker and produces one Wrangler script per environment.

Basic structure

import { defineWorker } from "@dragonmastery/tamer";

export const apiWorker = defineWorker({
  path: "workers/cf-app-api",        // project directory (relative to repo root)
  scriptName: "my-app-api",          // deployed script name
  main: "src/worker.ts",             // entrypoint

  resources: {
    d1: [{ logicalName: "settings", type: "single" }],
    r2: [{ logicalName: "assets" }],
    kv: [{ logicalName: "cache" }],
  },

  vars: {
    ENVIRONMENT: "local",
    LOG_LEVEL: "debug",
  },

  env: {
    dev: { vars: { ENVIRONMENT: "dev", LOG_LEVEL: "debug" } },
    prod: { vars: { ENVIRONMENT: "prod", LOG_LEVEL: "info" } },
  },
});

Key fields

path

Project directory for the worker, relative to the repo root. Tamer generates wrangler.json here (and wrangler.vitest.json on --env local), and runs wrangler types / wrangler deploy from this directory. Local generate: tamer wrangler --env local — see Local Development.

scriptName

The deployed Cloudflare script name. If omitted, Tamer derives a name from the stack identity and worker key ({stack}-{workerKey}-{env}, or {stack}-{workerKey} for local).

resources

Tamer-managed Cloudflare resources. Each kind expands to a wrangler binding plus a state row. See Resource Kinds.

vars

Runtime environment variables for the Worker. These land in wrangler.json and are also passed as env vars to the build step (if declared). See Values Lifecycle.

build

Pre-deploy build command (e.g. { command: "vite build" }). Tamer spawns it in the worker's path directory with resolved vars as environment variables. See SPA Build.

env / local

Per-env overrides. See Environments.

tamerRoutes

HTTP routes expanded per env. Zone-name routes are managed via the Workers Routes API (not written to wrangler.json). Custom-domain routes are written to wrangler.json.

doMigrations + resources.durableObjects

Managed Durable Object class bindings and append-only class migrations. Emitted as wrangler durable_objects + migrations on deploy / tenant provision. Instance census and in-DO SQL schema are app-owned. See Durable Objects.

secrets

Declares required secret names. Values come from the Tamer vault and are pushed on deploy. See Secrets.

durable_objects (passthrough)

Raw Wrangler durable_objects still passes through when you are not using managed resources.durableObjects / doMigrations. Mixing both on the same worker is rejected. tamer deploy's topological sort still reads durable_objects.bindings[].script_name so DO hosts deploy before dependents. See Field Boundary.

What lands in wrangler.json

Not all fields on the worker config appear in the generated wrangler.json. Tamer-only fields like path, resources, build, secrets, tamerRoutes are stripped. On --env local, Tamer also writes a wrangler.vitest.json sibling (remote stripped). See Field Boundary and Local Development.