> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thebay.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Services

> One entry per thing that gets built and run.

A service is one buildable, runnable unit. A monorepo with a web app and an API
is two services in one app, on one hostname, split by path.

## Identity and location

<ResponseField name="name" type="string">
  What this service is called. Used in logs and in `bay check` output.
</ResponseField>

<ResponseField name="dir" type="string" default=".">
  Where this service's commands run, relative to the repository root.
</ResponseField>

<ResponseField name="path" type="string" default="/">
  The path prefix this service serves, on the app's single hostname.

  Path routing rather than a hostname each: same origin means no CORS, and
  nothing to bake into a frontend bundle at build time.
</ResponseField>

## What it is

<ResponseField name="language" type="&#x22;node&#x22; | &#x22;python&#x22; | &#x22;static&#x22; | &#x22;other&#x22;" />

<ResponseField name="runtime" type="string">
  The interpreter or SDK this service needs — `python3.12`, `node22`, `java21`.

  Declared rather than detected, because the platform has exactly one version of
  each and the app is the only thing that knows which it was written against.
  Without it the pipeline notices a mismatch, logs that the build will probably
  fail on it, and builds anyway.
</ResponseField>

<ResponseField name="framework" type="string">
  One token that lets Bay inject proxy-awareness — `ALLOWED_HOSTS` for Django,
  `basePath` for Next, `ROOT_PATH` for FastAPI.

  Not decoration and not detection-as-a-service: an app behind a TLS-terminating
  proxy cannot configure itself for a proxy it has no way to know exists, so
  somebody has to say which mapping applies, and only the app knows.
</ResponseField>

## The phases

<ResponseField name="install" type="string" />

<ResponseField name="build" type="string" />

<ResponseField name="release" type="string">
  One-shot steps that run **once per deploy, before any traffic** — migrations,
  above all.

  Separate from `start` because folding a migration into the start command
  re-runs it on every cold start and every scale-out instance, concurrently.
  Prisma takes an advisory lock and survives that; Alembic does not.
</ResponseField>

<ResponseField name="start" type="string">
  The long-running command. Serves HTTP on `$PORT`.
</ResponseField>

<ResponseField name="processes" type="object">
  What this service runs beyond one web process — workers and crons, keyed by
  name. See [Processes](/configuration/processes).
</ResponseField>

## Static services

<ResponseField name="outputDir" type="string">
  The built directory, relative to `dir`.
</ResponseField>

<ResponseField name="spaFallback" type="boolean">
  Serve `index.html` for a path that matches no file.

  Without it a React Router app 404s on a refresh at `/about` — and nothing in
  the config can infer this, because the same directory is a correct answer for a
  multi-page site and a broken one for an SPA.
</ResponseField>

## Bringing your own image

<ResponseField name="dockerfile" type="string">
  A Dockerfile relative to the repository root.
</ResponseField>

<ResponseField name="context" type="string" default="dir">
  The build context that Dockerfile expects.
</ResponseField>

## Values

<ResponseField name="env" type="object">
  Non-secret literals, committed, deploy-shaping — `NODE_ENV`, `LOG_LEVEL`.
</ResponseField>

<ResponseField name="buildEnv" type="object">
  Baked into the bundle at **build** time and useless at runtime — `VITE_*`,
  `NEXT_PUBLIC_*`. A separate field because they are set at a different moment:
  setting them after the build means the build ran without them and the value
  never reached the shipped JavaScript.
</ResponseField>

<ResponseField name="secrets" type="string[]">
  Secret **names**, never values. Enforced: a name declared here and missing at
  deploy time fails before the build, rather than at runtime.
</ResponseField>

<ResponseField name="uses" type="(&#x22;database&#x22; | &#x22;bucket&#x22; | &#x22;redis&#x22; | &#x22;elasticsearch&#x22;)[]">
  Which shared resources this service receives credentials for. This is the unit
  that per-app database isolation is scoped to.
</ResponseField>

## Health and size

<ResponseField name="health" type="object">
  `{ "path": "/", "expect": 200 }`. What "the app responds" means — so success
  stops meaning "the process did not exit".
</ResponseField>

<ResponseField name="scale" type="object">
  `memory`, `cpu`, `maxInstances`, `timeout`, `concurrency`, `cpuBoost`. Every
  field optional; declaring one overrides only that one.
</ResponseField>