{"version":"2.1.288","anchor":"background-agent-launch-can-be-disabled-separately","canonical_anchor":"background-agent-launch-can-be-disabled-separately","heading":"claude mcp serve lists agent types and blocks background agents in restricted mode","tier":"use","area":"Background Agents","scope":"both","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.288\/e\/background-agent-launch-can-be-disabled-separately","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.288","markdown":"### `claude mcp serve` lists agent types and blocks background agents in restricted mode\n\n`claude mcp serve` now offers custom subagent types, and new switches can block background-agent launch and remote isolation, used in its http mode\n\n**Unclear.** It is not clear what sets `backgroundAgentLaunchDisabled` or whether a user can set it.\n\n**What**\n\n`claude mcp serve` runs Claude Code as an MCP server, so other programs can use its tools. A subagent is a helper Claude starts for a separate task.\n\n- `mcp serve` now loads your agent definitions before it lists tools or answers calls. The Agent tool description includes an `Available agent types:` list, and subagent calls use those definitions. Before, the lists were empty.\n\n- The internal restrictions gain `backgroundAgentLaunchDisabled` and `remoteAgentIsolationDisabled`, set by `disableBackgroundAgentLaunch()` and `disableRemoteAgentIsolation()`. Before, only background tasks, unsandboxed commands and a deadline could be disabled this way.\n\n- Background tasks now count as disabled when `backgroundAgentLaunchDisabled` is set. `CLAUDE_CODE_DISABLE_BACKGROUND_TASKS` works as before.\n\n- In the restricted (http) mode of `mcp serve`, background-agent launch and remote-agent isolation are both turned off.\n\n**Why**\n\nPrograms connected through `claude mcp serve` can now see and use your custom subagents. Background agents can be blocked without switching off every background task.\n\n- Area: Background Agents\n- Names: `backgroundAgentLaunchDisabled`\n- Tier: Use it now\n- Useful: 5\/5\n- Signal: 3\/5\n- Scope: both\n- Heads-up: no"}