Need help diagnosing Replit API startup failure: POLICY_INVALID

Bugs
1

Hi everyone,

I’m looking for technical guidance diagnosing an API startup failure in my Replit development workspace.

What is happening

  • The Vite frontend starts and the application page loads.

  • The Node.js/TypeScript API builds successfully.

  • However, the API exits with code 1 during startup, before opening its listening port.

  • API endpoints such as /api/healthz and /api/auth/me return HTTP 502.

The startup error

ControlledRunError: Startup boundary rejected: POLICY_INVALID
    at verifyAcceptancePolicyPayload
    at prepareStartup
    at startApplication

Relevant technical context

The application uses a custom guarded startup mode called acceptance. This is application-specific logic, not a standard Replit feature.

The startup validation expects:

  • A policy payload supplied as a string.

  • A separately configured SHA-256 integrity value containing exactly 64 lowercase hexadecimal characters.

  • A valid, unexpired authorization policy.

The error appears to occur during the initial payload/type/format validation, before hash comparison or policy-expiry validation.

A previous diagnostic check also indicated that the value received by the API for the SHA-256 integrity anchor did not appear to be in the expected hash format. We have not yet established why the API is receiving that value or where the configuration issue originates.

My questions

  1. What would you recommend checking to determine why the API is receiving an incorrectly formatted startup configuration value?

  2. Could Replit development-workspace configuration or runtime environment-variable delivery cause this type of issue?

  3. What is the safest way to trace the values from their configured source into the API startup process without exposing secrets?

  4. Which sanitized code excerpts or logs would help someone diagnose this?

I’m looking to restore normal API startup while preserving the existing validation and authorization safeguards. I do not want to disable the startup checks or bypass the security controls.

I appreciate any guidance or suggestions. Thank you!

2

So it is a bit hard to diagnose since this is code for your app. I use an agent to ask it what conditions create a POLICY_INVALID error once it does that instruct the agent it to make the validation more explicit on why its failing. If there are multiple policies in play, instruct it to include which policy is failing. One of those 3 conditions is tripping but we do not know which one. Once you have that the problem will be clearer.

I would also check if it works int the dev environment vs the production environment. If it works in one and not the other, most likely the secret configuration between the two environments and I would check the secrets pane within replit.