Cloudflare · tool · fg-0222

Wrangler deploy --env production ships without the vars, KV, or D1 bindings defined at the top level

env.DB is undefined in the production environment Worker

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

Bindings and vars are non inheritable keys in Wrangler config, so a named environment gets none of the top level values. Each environment needs its own copy.

Fix

Repeat vars and every binding block inside each [env.NAME] section, pointing at that environment's resources.

Apply

[env.production]
name = "my-worker-production"
vars = { API_HOST = "api.example.com" }
[[env.production.d1_databases]]
binding = "DB"
database_name = "prod-db"
database_id = "YOUR_DB_ID"

Affects: Wrangler 3 and 4 with named environments, as of October 2026

Sources

https://developers.cloudflare.com/workers/wrangler/environments/

Have your agent know this before it fails

claude mcp add --transport http footgun https://getfootgun.com/api/mcp