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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
One change · claude-code

Environment variables changed

env-vars

Nearest release: v2.1.280, published 10 hours before upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Upstream edited this page at 23 Sep 2026 01:47 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 23 Sep 2026 02:07 UTC.

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From line 297 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits83to this page, all time

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297297| `CLAUDE_CODE_IDE_SKIP_VALID_CHECK` | Set to `1` to skip validation of IDE lockfile entries during connection. Use when auto-connect fails to find your IDE despite it running |
298298| `CLAUDE_CODE_MAX_CONCURRENT_SUBAGENTS` | How many [subagents](/docs/en/sub-agents#concurrent-subagent-limit) can be running in one session before the Agent tool refuses to spawn another (default: 20). Accepts a positive whole number in plain digits; anything else is ignored, so the variable can adjust the cap but can't disable it. Requires Claude Code v2.1.217 or later |
299299| `CLAUDE_CODE_MAX_CONTEXT_TOKENS` | Override the context window size Claude Code assumes for the active model. As of v2.1.193, how it applies depends on how Claude Code resolves the model ID; see [Correct the window for a gateway or custom model ID](/docs/en/model-config#correct-the-window-for-a-gateway-or-custom-model-id). Use this when routing to a model through `ANTHROPIC_BASE_URL` whose context window does not match the built-in size for its name |
300| `CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH` | Maximum length in characters of each MCP tool description and each MCP server's instructions that Claude Code sends to the model (default: 2048). Claude Code [truncates longer text](/docs/en/mcp#for-mcp-server-authors). Accepts a positive whole number in plain digits. Anything else is ignored and the default applies. Requires Claude Code v2.1.280 or later |
300301| `CLAUDE_CODE_MAX_OUTPUT_TOKENS` | Set the maximum number of output tokens for most requests. Defaults and caps vary by model; see [max output tokens](https://platform.claude.com/docs/en/about-claude/models/overview#latest-models-comparison). Claude Code defaults to 32000 for model IDs it doesn't recognize, such as gateway-specific names, and lowers values above a model's cap to the cap. Increasing this value reduces the effective context window available before [auto-compaction](/docs/en/costs#reduce-token-usage) triggers |
301302| `CLAUDE_CODE_MAX_RETRIES` | Override the number of times to retry failed API requests (default: 10). Capped at 15 as of v2.1.186; as of v2.1.199, `CLAUDE_CODE_RETRY_WATCHDOG` raises the default and removes the cap. For unattended sessions that need to wait through longer outages, set `CLAUDE_CODE_RETRY_WATCHDOG` instead |
302303| `CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION` | Removed in v2.1.224 and now a no-op. Previously capped the total number of [subagents](/docs/en/sub-agents) Claude could spawn with the Agent tool in one session (default: 200); spawning past the cap failed with `Subagent spawn limit reached`. The [concurrent subagent limit](/docs/en/sub-agents#concurrent-subagent-limit) and the [depth limit](/docs/en/sub-agents#let-subagents-spawn-their-own-subagents) still apply |
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317318| `CLAUDE_CODE_OAUTH_REFRESH_TOKEN` | OAuth refresh token for Claude.ai authentication. When set, `claude auth login` exchanges this token directly instead of opening a browser. Requires `CLAUDE_CODE_OAUTH_SCOPES`. Useful for provisioning authentication in automated environments |
318319| `CLAUDE_CODE_OAUTH_SCOPES` | Space-separated OAuth scopes the refresh token was issued with, such as `"user:profile user:inference user:sessions:claude_code"`. Required when `CLAUDE_CODE_OAUTH_REFRESH_TOKEN` is set |
319320| `CLAUDE_CODE_OAUTH_TOKEN` | OAuth access token for claude.ai authentication. Alternative to `/login` for SDK and automated environments. Takes precedence over keychain-stored credentials. Generate one with [`claude setup-token`](/docs/en/authentication#generate-a-long-lived-token). Unless you run [`/login`](/docs/en/authentication#authentication-precedence), Claude Code uses the token you set for the whole session. To replace an expired token, generate a new one and restart |
320| `CLAUDE_CODE_OPUS_4_6_FAST_MODE_OVERRIDE` | Removed in v2.1.160 and now a no-op. Previously pinned [fast mode](/docs/en/fast-mode) to Claude Opus 4.6 instead of the current default. Opus 4.6 no longer supports fast mode |
321| `CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH` | Maximum length of content-bearing OpenTelemetry attributes (model responses, tool content, system prompts, raw API bodies), truncation marker included, in UTF-16 code units (default: 61440, i.e. 60 KB). Raise it only if your telemetry backend accepts attribute values larger than 64 KB, or lower it to cut telemetry volume. Requires Claude Code v2.1.214 or later. See [Monitoring](/docs/en/monitoring-usage)
321| `CLAUDE_CODE_OPUS_4_6_FAST_MODE_OVERRIDE` | Removed in v2.1.160 and now a no-op. Previously pinned [fast mode](/docs/en/fast-mode) to Claude Opus 4.6 instead of the current default. Opus 4.6 no longer supports fast mode
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