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Version: 22.4.0



Tower Agent enables Tower to launch pipelines on HPC clusters that do not allow direct access through an SSH client.

Tower Agent is a standalone process that runs on a node that can submit jobs to the cluster (e.g. login node). It establishes an authenticated secure reverse connection with Tower, allowing Tower to submit and monitor new jobs. The jobs are submitted on behalf of the user running the agent.


Tower Agent is distributed as a single executable file to simply download and execute.

  1. Download the latest release from Github:

    curl -fSL > tw-agent
  2. Make it executable:

    chmod +x ./tw-agent
  3. (Optional) Move it into a folder that is in your path.


Before running the Agent:

  1. Create a personal access token in Tower.

  2. Create Tower Agent credentials in a Tower workspace. See here for more instructions.

To share a single Tower Agent instance with all members of a workspace, create a Tower Agent credential with Shared agent enabled.

When you create the credentials you'll get an Agent Connection ID. You can use the default ID or enter a custom ID — the connection ID in the workspace credentials must match the ID entered when you run the agent.


The agent should always be running in order to accept incoming requests from Tower. We recommend that you use a terminal multiplexer like tmux or GNU Screen, so that it keeps running even if you close your SSH session.




  • If you are using the agent with Tower Enterprise (on-prem) you can set the API url using the TOWER_API_ENDPOINT environment variable or the --url option.
  • By default, the Agent uses the folder ${HOME}/work as the Nextflow work directory. You can change it using the --work-dir option.
  • The work directory must exist before running the agent.
  • You can also change the work directory in Tower when you create a compute environment or launch a pipeline.



Nextflow Tower Agent

* AGENT_CONNECTION_ID Agent connection ID to identify this agent.

* -t, --access-token=<token> Tower personal access token. If not provided TOWER_ACCESS_TOKEN variable will be used.
-u, --url=<url> Tower server API endpoint URL. If not provided TOWER_API_ENDPOINT variable will be used [default:].
-w, --work-dir=<workDir> Default path where the pipeline scratch data is stored. It can be changed when launching a pipeline from Tower [default: ~/work].
-h, --help Show this help message and exit.
-V, --version Print version information and exit.