---
title: Configure
description: Env vars, custom domains, collaborators, source edits, and storage for one app.
---

All of this lives on the app detail page (`/apps/<id>`, tabs Overview / Deployments / Metrics / Events / Settings).

## Environment variables

Settings → Environment. Variables reach the build, the release command, and the fleet environment. Reads are view-gated, writes admin-gated. Download mirrors the `.dev.vars` file local dev expects. Names starting with `FLAG_` render as on/off toggles (`1`/`0`).

Reserved prefixes are dropped silently: `PORT`, `HOST`, `AWS_*`, `S3_*`, `CELLD_*`, `RUNNER_*`, `NOITE_*`, `BETTER_AUTH_*`, `CADDY_*`, `LD_*`, `NODE_OPTIONS`, `BUN_*` (except the cache var). Full detail: [Environment variables](/reference/environment-variables).

## Custom domains

Settings → Custom Domain. Adding a hostname reserves it; the edge picks it up on the next reconcile (seconds). Then point DNS at the server:

```bash
dig +short app.<domain>
```

The certificate issues on the first visit (ask-gated on-demand TLS). Validation rules: lowercase DNS shape, ≥ 2 labels, no wildcard/IP/port/path. Platform hostnames are refused; a taken hostname returns 409. There is no DNS ownership check yet — first claimant wins.

Removing a hostname releases it.

## Collaborators

Settings → Collaborators. Roles, weakest first:

| Role | Can |
| --- | --- |
| `view` | Read the app, logs, metrics, storage |
| `push` | Everything above, plus push code (create + fast-forward only) |
| `admin` | Everything above, plus settings, env vars, domains, any push, collaborator management |

Instance admins (the [operator track](/self-hosting/install)) manage every app without a grant.

## Source browser and web commits

The **Code** button opens `/apps/<id>/source`: files of the latest pushed commit, a parent diff view, and deep links via `?view=` / `?file=`. Editing files there stages a web commit — it pushes like a deploy and wakes a sleeping app.

:::warning
The browser caps blobs at 256 KB and diffs at 1 MB. Binary files are detected, not rendered.
:::

## Storage

The Overview tab lists the app's storage resources; each row opens a detail browser. Kinds: D1 databases, Durable Objects, R2 buckets — as declared by the deployed Wrangler config (read first) or the pushed source. D1 tables page (`?p=`, `?s=`); R2 keys browse by prefix.