LOTP

wrangler

cli config-file eval-sh

References

wrangler is Cloudflare’s CLI for Workers. It auto-discovers wrangler.toml, wrangler.json or wrangler.jsonc in the current working directory.

Custom builds

The [build].command field is run via sh -c (Linux/macOS) or cmd (Windows) before the worker is bundled. The cwd and watch_dir fields control where the command runs and which directory triggers a rebuild during wrangler dev.

wrangler.toml:

name = "poc"
main = "src/index.js"
compatibility_date = "2024-01-01"

[build]
command = "<arbitrary_shell_command_goes_here>"
cwd = "."

wrangler.jsonc equivalent:

{
  "name": "poc",
  "main": "src/index.js",
  "compatibility_date": "2024-01-01",
  "build": {
    "command": "<arbitrary_shell_command_goes_here>"
  }
}

Subcommands that fire the build hook

Command Auth required Notes
wrangler deploy no hook fires before the auth check
wrangler deploy --dry-run no exits 0, useful when no creds are available
wrangler versions upload no same pre-auth fire as deploy
wrangler versions upload --dry-run no exits 0
wrangler dev no fires immediately on startup, then watches watch_dir
wrangler types no exits 0, lightest invocation
wrangler publish (v3 only) no deprecated alias of deploy; removed in v4 (errors Unknown argument: publish before the hook fires)

Inside the hook, the WRANGLER_COMMAND environment variable (wrangler v4+) reflects which subcommand triggered the build (deploy, dev, types, …).

The following subcommands do not read the [build] section: wrangler whoami, wrangler secret, wrangler kv, wrangler tail, wrangler triggers deploy.

GitHub Actions

cloudflare/wrangler-action defaults to wrangler deploy, so any workflow using it without overriding command: is a sink.

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