Resolving "Client network socket disconnected before secure TLS connection was established" in Deno GCP

18/01/2026

As part of my full-stack volunteering work, I was tasked with developing a Supabase edge function for fetching and storing events. Our project used GCP Secret Manager to store API keys which meant I would need to access it in the function. Since Supabase uses Deno as its runtime, I encountered this problem during development where any connection to GCP's services was not possible, leaving this cryptic error.

It turns out this error is caused by a breaking change to the grpc/grpc-js package. While the reason is currently unknown, it's suspected that new versions of grpc-js creating explicit TCP sockets to attempt to form a TLS session which is then used to establish a HTTP connection. This is a different protocol over older versions which used the http2 module.

At this moment, no fix for Deno has been officially published which leaves us with two solutions.

• Downgrading grpc/grpc-js to a version <= 1.12.6
• For any packages under the @google-cloud namespace, client classes should have a boolean fallback option that allows for an alternative transport implementation to be used over grpc.

For my case, I was able to use the fallback option and everything worked fine.

const client = new SecretManagerServiceClient({ 
credentials: {
  client_email: Deno.env.get("GOOGLE_SERVICE_ACCOUNT_CLIENT_EMAIL")!,
  private_key: Deno.env.get("GOOGLE_SERVICE_ACCOUNT_PRIVATE_KEY")!
}, 
fallback: true
});