diff --git a/autocomplete/fish_autocomplete b/autocomplete/fish_autocomplete
index 13ccd2e8..9988c16a 100644
--- a/autocomplete/fish_autocomplete
+++ b/autocomplete/fish_autocomplete
@@ -80,6 +80,7 @@ complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcomma
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from config' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from config; and not __fish_seen_subcommand_from help h' -a 'help' -d 'Shows a list of commands or help for one command'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and not __fish_seen_subcommand_from init create dockerfile config deploy status update restart rollback logs tail delete destroy versions list secrets update-secrets private-link start dev console simulate help h' -a 'deploy' -d 'Deploy a new version of the agent'
+complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from deploy' -f -l id -r -d '`ID` of the agent. If unset, and the livekit.toml file is present, will use the id found there.'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from deploy' -f -l secrets -r -d 'KEY=VALUE comma separated secrets. These will be injected as environment variables into the agent. These take precedence over secrets-file.'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from deploy' -l secrets-file -r -d '`FILE` containing secret KEY=VALUE pairs, one per line. These will be injected as environment variables into the agent.'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from deploy' -f -l secret-mount -r -d 'Local path to a secret file to be mounted on agent environment'
diff --git a/cmd/lk/agent.go b/cmd/lk/agent.go
index a61f6cb5..fc9cc38a 100644
--- a/cmd/lk/agent.go
+++ b/cmd/lk/agent.go
@@ -221,6 +221,7 @@ var (
 					Before: createAgentClient,
 					Action: deployAgent,
 					Flags: []cli.Flag{
+						idFlag(false),
 						secretsFlag,
 						secretsFileFlag,
 						secretsMountFlag,
diff --git a/cmd/lk/agent_test.go b/cmd/lk/agent_test.go
index 1d2551f6..4c54085e 100644
--- a/cmd/lk/agent_test.go
+++ b/cmd/lk/agent_test.go
@@ -456,3 +456,21 @@ func TestRequireSecrets_QuietSuppressesStatus(t *testing.T) {
 		})
 	}
 }
+
+// TestAgentDeployRegistersIDFlag is a regression test for #830: `lk agent deploy`
+// resolves the agent via getAgentID, which reads cmd.String("id"). The deploy
+// subcommand must therefore register the --id flag; it previously omitted it, so
+// `lk agent deploy --id ...` failed at flag-parse time with "flag provided but not defined".
+func TestAgentDeployRegistersIDFlag(t *testing.T) {
+	agentCmd := findCommandByName(AgentCommands, "agent")
+	require.NotNil(t, agentCmd, "top-level 'agent' command must exist")
+
+	deployCmd := findCommandByName(agentCmd.Commands, "deploy")
+	require.NotNil(t, deployCmd, "'agent deploy' command must exist")
+
+	var names []string
+	for _, f := range deployCmd.Flags {
+		names = append(names, f.Names()...)
+	}
+	require.Contains(t, names, "id", "'agent deploy' must register the --id flag")
+}