demoUrl missing environment variables

[Railly]

When creating a project with environment variables, the demoUrl returned by v0.chats.create() doesn't have access to those env vars.

Repro:

  const project = await v0.projects.create({
    name: 'Test',
    environmentVariables: [
      { key: 'NEXT_PUBLIC_API_KEY', value: 'test_123' }
    ]
  })

  const chat = await v0.chats.create({
    projectId: project.id,
    message: 'console.log process.env values'
  })

  // Browser console on demoUrl shows:
  // NEXT_PUBLIC_API_KEY: undefined

Verified:

• Env vars ARE stored: v0.projects.findEnvVars()returns them
• Env vars work in v0.dev editor
• Env vars are undefined in demoUrl
• Tested with v0-clone tepmlate, same issue

Impact:
Breaks apps that need env vars to run. Example: Clerk auth shows blank screen because NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY is undefined.

[ctate]

Hi @Railly - env vars aren't currently supported by demoUrl to avoid potential exposure of sensitive data. We're exploring ways to add this functionality safely in the future. In the meantime, to use env vars, please create a deployment with them using v0.deployments.create() for the associated project.

[tea-artist]

+1 This is blocking real development

Without env vars in demoUrl, we can't debug any external integrations in preview.

Real problem:

Can't test against:

• Database connections - our own DB endpoints
• API services - backend integrations
• Auth providers - Clerk/Auth0 all break
• Third-party APIs - Stripe, payment gateways, etc.

Why deployment isn't enough:

Yes, v0.deployments.create() supports env vars, but deployments lack debugging tools:

• Minified/compressed code
• No source maps
• No dev console details
• Can't track down issues when things break

We need preview with env vars for the dev/debug cycle. Deployments are for production, not debugging.

Current situation:

1. Build something with external APIs
2. Preview is broken (no env vars) ❌
3. Deploy to debug (slow + hard to trace minified code) ❌
4. End up copying everything to local just to see what's wrong

This defeats the whole point of having a preview URL.

Preview should work like local dev - if env vars are configured, they should just work.

[kostiushko-vlad]

This defeats the whole point of having a preview URL.

I agree, it forces to write env vars to the .env.local file which is even bigger security problem.
Or create own preview deployment system, but that requires a lot more effort.

[ctate]

Hi all, thank you for the feedback! We are adding this feature to the API soon and will update this thread as soon as it is released.