This article follows the official documentation. We haven’t tested this tool for a hands-on review.
When a coding agent needs to inspect video assets in a Mux project, the Mux CLI lets it send requests to Mux from a shell to work with video assets, live streams, playback IDs, and other Mux services. The --agent flag tells the CLI to print command results as JSON, a format an agent can read and use.
For example, an agent can list existing assets and report which ones match a task without changing them. The CLI uses your Mux account, so the credentials in the agent’s environment determine which account it can access. The official Mux CLI documentation covers the tool’s commands and setup.
Install and authenticate
On macOS or Linux with Homebrew, install the CLI with:
brew install muxinc/tap/mux
Mux also documents installation through npm and downloadable binaries in the CLI repository.
Run the browser-based sign-in command before asking an agent to use the CLI:
mux login
The command opens the Mux Dashboard so you can authenticate. The CLI also accepts Mux API access tokens through the MUX_TOKEN_ID and MUX_TOKEN_SECRET environment variables. Those variables take precedence over saved login credentials, so check whether they are set if the CLI appears to use the wrong account. Store tokens outside the agent prompt, such as in the environment provided to the agent.
List assets without changing them
Start by finding existing assets that match a project need. Ask the CLI for its asset commands, then list assets in agent-readable output:
mux assets --help
mux assets list --agent
The first command lists the asset subcommands supported by the installed CLI. The second asks Mux for the assets and prints the results as JSON. The agent can read the returned asset records and summarize the relevant ones. This example only reads account data; it does not create, update, or delete an asset.
A realistic prompt for this task is:
Use the Mux CLI to list the assets in the authenticated account. Identify assets that match the video names in this repository, summarize the matching records, and do not create or modify anything.
Describe the result you want in the prompt, but keep account secrets out of it. Before the agent runs the command, make sure the shell has credentials for the Mux account you intend to use. The output format does not limit which commands the agent can run. Commands that upload or change assets still affect your account.
Mux says --agent also identifies the CLI as an agent in the HTTP User-Agent header. That lets Mux distinguish agent-driven CLI use from human use. The flag changes output and identifies the caller; it does not add a permission boundary or make write commands read-only. See Mux’s explanation of agent-oriented CLI behavior.
Test webhook handling locally
A webhook is an HTTP request that Mux sends to notify a service about an event, such as a video becoming ready. If you are working on a service that receives Mux webhooks, the CLI can forward real-time events to a local server or send a simulated event locally for testing. The CLI documents mux webhooks listen --forward-to for forwarding events and mux webhooks trigger for sending a simulated event.
Before using either command, inspect its available arguments:
mux webhooks listen --help
mux webhooks trigger --help
Use the flags shown by the installed CLI to direct the listener to your local webhook route or to choose which event to trigger. The listener connects to Mux to receive real events. The trigger sends a simulated event locally without creating a real asset or making an API call. Mux says the CLI saves webhook events in a local SQLite database. You can use mux webhooks events replay to replay a saved event without uploading the video again.
The listener needs a live connection to Mux’s event stream. The documentation does not say what happens to real-time delivery if the connection drops, so the listener does not confirm that every event reached your local server. For the signing behavior and event replay details, see Mux’s webhook CLI overview.
Know what the agent flag changes
Mux processes video asynchronously, so an upload can finish before the asset is ready to play. For commands that create an asset, Mux documents a --wait flag that checks repeatedly until the asset is ready. An agent can use this flag to wait in one command instead of relying on a webhook handler. The command remains open while Mux processes the asset.
The CLI supports many operations beyond listing assets, including live stream, playback, and Mux Data commands. Before giving an agent a broader task, use mux --help or a command’s --help output to check the available syntax. The examples here describe documented behavior; the CLI was not installed or tested for this article.