{"name":"CLAUDE_CODE_SIMPLE","slug":"claude-code-simple","family":"env","title":"Environment variables","noun":"environment variable","description":"When a coordinator agent cannot use a tool, Claude is told to run it from a worker.","description_source":"entry","described_by":{"version":"2.1.227","anchor":"coordinator-agents-told-to-hand-blocked-tools-to-a-worker"},"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":"2.1.50","released_at":"2026-02-20 23:09:38","spans":2}},"aliases":[],"entries":[{"version":"2.1.295","anchor":"new-claude-code-restrict-personal-config-env-var-recognized","heading":"New CLAUDE_CODE_RESTRICT_PERSONAL_CONFIG mode restricts your own Claude Code files","line":"Setting `CLAUDE_CODE_RESTRICT_PERSONAL_CONFIG` starts a session that restricts your own Claude Code files, alongside the other restricted modes","released_at":"2026-10-08 18:22:58","reason":"found in this entry's text"},{"version":"2.1.283","anchor":"context-shows-mcp-server-instructions-as-a-separate-categor","heading":"\/context lists MCP server instructions as their own category","line":"The `\/context` breakdown now shows how much of the context MCP server instructions take up, next to MCP tools","released_at":"2026-09-25 18:46:11","reason":"found in this entry's text"},{"version":"2.1.282","anchor":"attachment-builder-records-wire-shape-settings-before-declar","heading":"Internal change to how tool information is prepared for the model","line":"Claude Code now records message-format settings before preparing tool details, and reorders attachments in bare or `CLAUDE_CODE_SIMPLE` mode","released_at":"2026-09-24 15:56:22","reason":"found in this entry's text, named in this entry"},{"version":"2.1.280","anchor":"builtin-hooks-module-capability-manifests-expanded","heading":"Builtin hooks-module capability manifests expanded","line":"Builtin plugin hook modules were granted access to more host calls, including two new environment variables","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"version":"2.1.251","anchor":"a-stripped-down-system-prompt-mode-off-in-this-build","heading":"A stripped-down system prompt mode, off in this build","line":"A mode keeps the system prompt static and moves environment details into conversation reminders, off by default.","released_at":"2026-08-28 15:34:26","reason":"found in this entry's text"},{"version":"2.1.248","anchor":"retaining-tool-definitions-across-context-loss-and-credentia","heading":"Retaining tool definitions across context loss and credential changes, off by default","line":"Tool definitions could survive context loss and credential changes, but both halves are off.","released_at":"2026-08-27 20:35:36","reason":"found in this entry's text"},{"version":"2.1.234","anchor":"built-in-mcp-server-gains-schema-validation-cancellation-and","heading":"Built-in MCP server gains schema validation, cancellation, and an unreachable locked-down HTTP mode","line":"The MCP server you expose now validates tool arguments and aborts work when a client cancels.","released_at":"2026-08-17 18:19:13","reason":"found in this entry's text"},{"version":"2.1.233","anchor":"remaining-token-countdown-is-now-on-by-default","heading":"Remaining-token countdown is now on by default","line":"Claude now gets a running count of tokens left by default, re-anchored on each of your prompts.","released_at":"2026-08-14 18:50:44","reason":"found in this entry's text"},{"version":"2.1.232","anchor":"a-built-in-web-fetch-subagent-that-takes-over-page-fetching-","heading":"A built-in \"web-fetch\" subagent that takes over page fetching, off by default","line":"A built-in web-fetch agent can take over page fetching and summarise pages, off by default.","released_at":"2026-08-13 21:30:53","reason":"found in this entry's text"},{"version":"2.1.232","anchor":"web-fetching-can-be-routed-through-a-built-in-agent","heading":"Web fetching can be routed through a built-in agent","line":"Fetches can be handed to a dedicated agent, but the server flag defaults off.","released_at":"2026-08-13 21:30:53","reason":"named in this entry, found in this entry's text"}],"entries_total":13,"docs":[{"source":"claude-code","path":"agent-sdk\/modifying-system-prompts","title":"Modifying system prompts","documented":false},{"source":"claude-code","path":"cli-reference","title":"CLI reference","documented":false},{"source":"claude-code","path":"output-styles","title":"Output styles","documented":false}],"docs_total":3,"gates":[],"related":[{"name":"CLAUDE_CODE_3P_PROBE_WROTE_HAIKU_DEFAULT","slug":"claude-code-3p-probe-wrote-haiku-default","description":"If your cloud account cannot use a model, Claude Code can step down to the next one; `CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK` turns this off"},{"name":"CLAUDE_CODE_3P_PROBE_WROTE_OPUS_DEFAULT","slug":"claude-code-3p-probe-wrote-opus-default","description":"Internal marker on third-party providers. When Claude Code itself writes `ANTHROPIC_DEFAULT_OPUS_MODEL` into its environment (the model availability probe on Bedrock, Vertex or Mantle, or a move down the model fallback ladder), it sets this variable to the same model ID. An `ANTHROPIC_DEFAULT_OPUS_MODEL` equal to it is treated as Claude Code's own choice rather than a user pin: it does not count as pinned, the probe does not skip it, and the fallback ladder may move it."},{"name":"CLAUDE_CODE_3P_PROBE_WROTE_SONNET_DEFAULT","slug":"claude-code-3p-probe-wrote-sonnet-default","description":"On third-party providers, Haiku model names are no longer skipped by the check that sets up the Sonnet default model"},{"name":"CLAUDE_CODE_3P_SEEDED_OPUS_DEFAULT","slug":"claude-code-3p-seeded-opus-default","description":"If your cloud account cannot use a model, Claude Code can step down to the next one; `CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK` turns this off"},{"name":"CLAUDE_CODE_3P_SEEDED_SONNET_DEFAULT","slug":"claude-code-3p-seeded-sonnet-default","description":"If your cloud account cannot use a model, Claude Code can step down to the next one; `CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK` turns this off"},{"name":"CLAUDE_CODE_ACCESSIBILITY","slug":"claude-code-accessibility","description":"Set to `1` to keep the native terminal cursor visible and disable the inverted-text cursor indicator. Allows screen magnifiers like macOS Zoom to track cursor position"},{"name":"CLAUDE_CODE_ACCOUNT_TAGGED_ID","slug":"claude-code-account-tagged-id","description":"Overrides the `user.account_id` attribute Claude Code attaches to its OpenTelemetry data. It applies only when an account UUID is known and `OTEL_METRICS_INCLUDE_ACCOUNT_UUID` is not turned off (default on); when unset or empty, `user.account_id` is derived from the account UUID as a tagged ID of the form `user_01...`."},{"name":"CLAUDE_CODE_ACCOUNT_UUID","slug":"claude-code-account-uuid","description":"The device bridge is skipped entirely when the host's account UUID doesn't match the stored one."},{"name":"CLAUDE_CODE_ACT_DONT_REDERIVE","slug":"claude-code-act-dont-rederive","description":"Three existing feature gates moved position; their defaults are unchanged."},{"name":"CLAUDE_CODE_ACTION","slug":"claude-code-action","description":"Marks a run as coming from the Claude Code GitHub Action. A truthy value (`1`, `true`, `yes` or `on`) makes Claude Code set `CLAUDE_CODE_ENTRYPOINT` to `claude-code-github-action`, but only when `CLAUDE_CODE_ENTRYPOINT` is not already set and the command is not `claude mcp serve`. It is also reported as `isClaudeCodeAction` in the environment details attached to telemetry."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-code-simple","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}