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Sweep 02 Oct 2026 · 18:55Z Build v2.1.288 509 read Stable v2.1.285 Latest v2.1.288 Next v2.1.288 Feeds RSS JSON llms.txt llms-full.txt Unofficial
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Claude Code v2.1.288 ·

claude mcp serve lists agent types and blocks background agents in restricted mode

claude mcp serve now offers custom subagent types, and new switches can block background-agent launch and remote isolation, used in its http mode

Group of 3 Use it now No documentation found New Features
JSON All of v2.1.288
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5Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Background AgentsArea: what it touches
New FeaturesKind: in v2.1.288,
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What

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.

  • 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.
  • 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.
  • Background tasks now count as disabled when backgroundAgentLaunchDisabled is set. CLAUDE_CODE_DISABLE_BACKGROUND_TASKS works as before.
  • In the restricted (http) mode of mcp serve, background-agent launch and remote-agent isolation are both turned off.

Why

Programs connected through claude mcp serve can now see and use your custom subagents. Background agents can be blocked without switching off every background task.

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Names in the bundlebackgroundAgentLaunchDisabled
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Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtIt is not clear what sets `backgroundAgentLaunchDisabled` or whether a user can set it.

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