ts-dotenv-override

name	ts-dotenv-override
description	Ensures .env files in TypeScript projects override sops-nix shell secrets. Use when setting up env loading, debugging missing/wrong API keys, or configuring dotenv in TS projects.

TypeScript .env Override for sops-nix

Activation

When this skill is triggered, ALWAYS display this banner first:

╭─────────────────────────────────────────────────────────────╮
│  🔑 SKILL ACTIVATED: ts-dotenv-override                      │
├─────────────────────────────────────────────────────────────┤
│  Mode: [Setup | Debug | Fix]                                │
│  Action: Ensuring .env overrides sops-nix shell secrets     │
╰─────────────────────────────────────────────────────────────╯

Replace [Mode] with the detected trigger type.

Background

This system uses sops-nix to decrypt secrets and export them as shell environment variables on every Fish shell startup (via conf.d/secrets.fish). These include API keys like OPENROUTER_API_KEY, EXA_API_KEY, TAVILY_API_KEY, etc.

The problem: most .env loaders in TypeScript/Node.js do not override existing environment variables by default. So the sops-nix value always wins over the project-local .env value, which causes confusion when projects need different keys or per-project configuration.

Auto-loaded sops-nix secrets (always in shell env)

Secret Path	Env Var
openrouter/api-key	OPENROUTER_API_KEY
exa/api-key	EXA_API_KEY
tavily/api-key	TAVILY_API_KEY
serper/api-key	SERPER_API_KEY

These are set by ~/.config/fish/conf.d/secrets.fish before any project code runs.

When to Use

This skill activates when:

• Setting up .env / dotenv in a TypeScript project
• "my .env isn't working" or "wrong API key being used"
• "env variable not picking up from .env"
• "sops secret overriding .env"
• Configuring environment loading in Next.js, Vite, Hono, Express, or plain Node/Bun projects
• Creating a new TypeScript project that uses API keys

Rules

1. ALWAYS configure dotenv with override: true in TypeScript projects.

2. ALWAYS check for sops-nix conflicts when debugging env var issues.

3. NEVER assume .env values will win over shell environment by default.

Fix by Framework / Runtime

Plain dotenv (Node.js)

// ❌ WRONG — does NOT override existing env vars
import 'dotenv/config'

// ✅ CORRECT — overrides sops-nix shell secrets
import dotenv from 'dotenv'
dotenv.config({ override: true })

If using multiple .env files:

import dotenv from 'dotenv'

// Load base, then overrides (last one wins)
dotenv.config({ path: '.env', override: true })
dotenv.config({ path: '.env.local', override: true })

Bun

Bun auto-loads .env but does not override existing env vars. Fix:

// At the very top of your entry point
import dotenv from 'dotenv'
dotenv.config({ override: true })

Or use the shell workaround:

# Unset conflicting vars before running
env -u OPENROUTER_API_KEY bun run dev

Next.js

Next.js loads .env files automatically with this precedence:

1. .env.$(NODE_ENV).local (highest)
2. .env.local
3. .env.$(NODE_ENV)
4. .env (lowest)

But it still does NOT override existing shell env vars.

Fix — add to the top of next.config.ts (or next.config.mjs):

import dotenv from 'dotenv'
dotenv.config({ path: '.env.local', override: true })

Or use @next/env explicitly:

import { loadEnvConfig } from '@next/env'
loadEnvConfig(process.cwd(), true) // second arg = force override dev mode

Vite

Vite loads .env files but respects existing env vars. Fix in vite.config.ts:

import { defineConfig, loadEnv } from 'vite'

export default defineConfig(({ mode }) => {
  // loadEnv with prefix '' loads all vars, not just VITE_*
  const env = loadEnv(mode, process.cwd(), '')
  return {
    define: {
      // Explicitly override process.env for server-side
      'process.env.OPENROUTER_API_KEY': JSON.stringify(env.OPENROUTER_API_KEY),
    },
  }
})

Hono / Express / Fastify (server-side)

Add at the very first line of your entry point (before any imports that read env):

import dotenv from 'dotenv'
dotenv.config({ override: true })

// Now import everything else
import { Hono } from 'hono'
// ...

T3 Env (@t3-oss/env-*)

T3 Env validates env vars but reads from process.env — which already has sops values. Ensure dotenv override runs before the T3 schema is evaluated:

// env.ts
import dotenv from 'dotenv'
dotenv.config({ override: true })

import { createEnv } from '@t3-oss/env-core'
// ...

Wrangler (Cloudflare Workers)

Wrangler uses .dev.vars for local secrets — these properly override. No fix needed for local dev. For wrangler.toml vars, they are bundled at build time and don't conflict.

Debugging Checklist

When a user reports wrong/stale env vars in a TypeScript project:

1. Check if the var is auto-loaded by sops-nix:

   echo $OPENROUTER_API_KEY  # If set, sops-nix loaded it
   

2. Check the project's .env file:

   grep OPENROUTER_API_KEY .env .env.local 2>/dev/null
   

3. Check how dotenv is configured:

   grep -r "dotenv" src/ --include="*.ts" --include="*.mts" --include="*.js"
   

4. Verify override is enabled: Look for override: true in dotenv config. If missing, that's the fix.

5. Nuclear option — unset before running:

   env -u OPENROUTER_API_KEY -u EXA_API_KEY bun run dev
   

Helper: fish function

A convenience function is available in the shell config:

# Run any command with .env values overriding shell env
function with-dotenv
    if test -f .env
        env (grep -v '^#' .env | grep '=' | xargs) $argv
    else
        echo "No .env file found in current directory" >&2
        return 1
    end
end

# Usage:
# with-dotenv bun run dev
# with-dotenv node server.js

To add this function, edit nixpkgs/home/fish.nix and add it to programs.fish.functions.

Red Flags

❌ Using import 'dotenv/config' without override (will NOT override sops-nix vars) ❌ Assuming .env values win over shell environment ❌ Debugging "wrong API key" without checking echo $VAR_NAME in shell first ❌ Hardcoding API keys in source code to "fix" the override issue ❌ Using process.env.VAR = "value" to override (fragile, not portable)

Success Criteria

✅ Project .env values are used when running the app, not sops-nix shell values ✅ dotenv.config({ override: true }) is present in the entry point ✅ Override runs before any code that reads process.env ✅ No API keys are hardcoded or committed to git