VNC#

Using VNC#

VNC (Virtual Network Computing) is a remote desktop technology. It allows you to view the robot's computer screen and control it using a mouse and keyboard through a browser.

How it works#

User's browser
    │ WebSocket (port 6080-6100)
    ▼
orchestrator-vnc-proxy (websockify)
    │ TCP (VNC port, usually 5900)
    ▼
VNC server on the robot's computer

The user clicks a button → the Orchestrator creates a proxy connection via websockify → the browser connects to the robot's screen.

Setup#

1. Each robot must have a VNC server#

Install a VNC server on the robot's computer.

• Password and port configuration is done in the Assistant settings, on the "Execution/VNC Server" tab

Fields to fill in the Assistant:

• Robot VNC Port
• VNC Password
• Checkbox "Start VNC server when robot starts"
• Checkbox "Automatically start VNC server when Unattended robot starts"

Make sure the VNC server is running, its actual port is open in the firewall on the robot's computer, and the VNC password is set.

2. Fill in VNC data in the robot card#

In the Orchestrator, open the robot card (edit) and fill in the fields:

Where to get the password: The password is set when the VNC server is installed on the robot's computer. This is a separate VNC password, NOT the Windows user password and NOT the account password in the Orchestrator.

The VNC password must be at most 128 characters and 255 UTF-8 bytes, with no spaces or other whitespace characters.

Where to get the fingerprint: Copy it from the VNC settings of Sherpa RPA running under the same Windows account as ProcessAgent. Confirm it with the robot administrator through a trusted channel before saving the robot card. Update the stored fingerprint if the VNC server key changes.

3. User access permissions#

The user role must have VNC (access_vnc) permission with Read and Update rights:

1. Go to the Roles section
2. Select the required role
3. Find the access_vnc field and check the Read and Update boxes
4. Save

(If you do not have rights to edit roles, contact the administrator)

Using VNC#

Method 1: Connect to the robot from the table#

1. Go to the Robots section
2. In the row of the required robot, click the monitor icon (rightmost column)
3. A new tab will open with the robot's screen

If the robot card has an address, password, and trusted server key fingerprint, connection starts automatically. If the fingerprint is missing, the form opens, but connection cannot proceed without it. The browser verifies the server key before sending credentials.

Method 2: Connect manually via VNC Viewer#

1. Open in browser: https://YOUR_ORCHESTRATOR/main/vnc-viewer

2. Fill in the form:

   Field	What to enter
   VNC Server (host:port)	Robot IP address and VNC port (e.g., 192.168.1.100:5900)
   Password	VNC password
   Server key SHA-256 fingerprint	Trusted fingerprint from the robot's VNC settings: 32 pairs of hexadecimal digits separated by colons
   Login (optional)	Login, if required by the VNC server

If the fingerprint is missing, malformed, or does not match the server key, the connection is stopped. Do not bypass this check; confirm the correct fingerprint with the robot administrator.

Disconnecting#

• Click the red "Disconnect" button in the upper left corner
• Or simply close the browser tab

The proxy service will automatically stop and free the port.

VNC environment variables (.env)#

Port list#

Possible issues#