Great question! Assuming you’re on Prefect 3.x, you’ve got a few options depending on how and where you want to share access. Quickest way (same LAN) - Start the local server bound to all interfaces and pick a port:

prefect server start --host 0.0.0.0 --port 4200

- Make sure your OS firewall allows inbound traffic on that port. - Share your machine’s IP and port with your teammates (e.g., http://YOUR-IP:4200). - Note: This serves both the API and the UI on the same host:port. More secure (SSH tunnel, no network exposure) - Keep the server bound to localhost:

prefect server start --host 127.0.0.1 --port 4200

- Each teammate creates a tunnel from their machine:

ssh -N -L 4200:localhost:4200 user@YOUR-HOST

- They visit http://localhost:4200 on their machine. Internet exposure (production-ish) - Don’t expose Prefect directly to the internet; put it behind a reverse proxy with TLS and authentication (e.g., Nginx, Caddy, or Traefik). - You may need to set

PREFECT_API_URL

(for API consumers like workers) and ensure the UI can reach the API via the same origin or a configured URL if you’re using a path prefix/reverse proxy. - Docs and examples: - Self-hosting the Prefect API and UI - Security considerations and settings - Example with reverse proxy: Reverse proxy example Consider Prefect Cloud (easiest sharing + auth) - If you want a hosted, shared UI with built-in auth and secure access, Prefect Cloud is the simplest path. You’d run your flows anywhere and connect to Cloud for the UI/API. Important notes - The local server has no built-in auth. Anyone who can reach it can use the UI and API, so prefer SSH tunneling, VPN, or a reverse proxy with TLS + auth for anything beyond a trusted LAN. - If you’re running in Docker, remember to publish the port (e.g.,

-p 4200:4200

) and still bind the server to

0.0.0.0

inside the container. Would you like to share on your local network only, or make it accessible over the internet? I can tailor steps (and example configs) based on that.

@Marvin When I try the "quickest way" method from above, I can see the GUI from another machine, but none of the deployments exist like they do locally. What is going on?

That error usually means your client is pointing at an unroutable address.

0.0.0.0

(and especially

0.0.0

) is a “bind” address the server uses to listen on all interfaces — it’s not a valid address for clients to call. Point your client at a concrete address instead. Quick fixes by scenario: - Local server + local client (same machine): - Use

<http://127.0.0.1:4200/api>

or

<http://localhost:4200/api>

- Update your config:

prefect config set PREFECT_API_URL=<http://127.0.0.1:4200/api>

- Local server in Docker, client on the host: - Start/bind the server and publish the port:

prefect server start --host 0.0.0.0 --port 4200

If running the server in a Docker container, ensure the container maps the port:

docker run -p 4200:4200 your-server-image

- Client URL:

<http://127.0.0.1:4200/api>

- Server in Docker and client in another container: - Put both containers on the same user-defined Docker network and use the server container’s name:

http://<server-container-name>:4200/api

- Server on a remote VM: - Start the server binding to all interfaces:

prefect server start --host 0.0.0.0 --port 4200

- Open firewall/security group for port 4200. - Client URL:

http://<vm-public-ip-or-dns>:4200/api

How to inspect and correct your Prefect config (Prefect 3.x): - View current settings and sources:

prefect config view --show-sources

If you see

PREFECT_API_URL=<http://0.0.0.0:4200/api>

(or `http://0.0.0:4200/api`), change it:

prefect config set PREFECT_API_URL=<http://127.0.0.1:4200/api>

- You can also set it via environment variables: - macOS/Linux:

export PREFECT_API_URL=<http://127.0.0.1:4200/api>

- PowerShell:

$env:PREFECT_API_URL = "<http://127.0.0.1:4200/api>"

Useful references: - Manage settings: Manage settings - Self-hosted server (Docker): Run Prefect Server with Docker - Helm/Kubernetes: Helm install for Prefect Server A couple of checks: - Make sure the server is actually running and reachable in a browser at the right host: http://127.0.0.1:4200 locally, or your VM’s IP/DNS if remote. - The API must always be a concrete, routable address for the client (never

0.0.0.0

). If you can share a bit more about your setup, I can tailor the exact URL and commands: - Where is the Prefect Server running (your laptop, a container, a remote VM)? - From where is your code/worker/agent trying to connect? - How are you starting the server right now?