{"name":"CLAUDE_AGENT_SDK_DISABLE_BUILTIN_AGENTS","slug":"claude-agent-sdk-disable-builtin-agents","family":"env","title":"Environment variables","noun":"environment variable","description":"Set to `1` to disable all built-in [subagent](\/docs\/en\/sub-agents) types such as Explore and Plan. Only applies in non-interactive mode (the `-p` flag). Useful for SDK users who want a blank slate. This also removes `general-purpose`, the subagent Claude Code runs when an Agent tool call omits `subagent_type`. Such a call then fails with [`subagent_type is required`](\/docs\/en\/errors#subagent-type-is-required)","description_source":"docs","described_by":{"doc":"claude-code\/env-vars","title":"Environment variables"},"presence":{"first_seen":"2.1.138","removed_in":null,"in_current_build":true,"newest_mined":"2.1.308","builds":149,"mined_builds":149,"first_cited":{"version":"2.1.232","released_at":"2026-08-13 21:30:53","spans":1}},"aliases":[],"entries":[{"version":"2.1.232","anchor":"built-in-agent-selection-is-now-a-single-three-way-decision","heading":"Built-in agent selection is now a single three-way decision","line":"One resolver now picks no agents, coordinator or default, and the disable env var works as before.","released_at":"2026-08-13 21:30:53","reason":"named in this entry, found in this entry's text"}],"entries_total":1,"docs":[{"source":"claude-code","path":"env-vars","title":"Environment variables","documented":true},{"source":"claude-code","path":"agent-sdk\/subagents","title":"Subagents in the SDK","documented":false},{"source":"claude-code","path":"sub-agents","title":"Create custom subagents","documented":false}],"docs_total":3,"gates":[],"related":[{"name":"CLAUDE_AGENT_SDK_DISABLE_MCP_MANIFESTS","slug":"claude-agent-sdk-disable-mcp-manifests","description":"The Agent SDK can now read tool lists from in-process MCP servers itself and pass them to the CLI when it starts"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-agent-sdk-disable-builtin-agents","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}