Claude docs changes for August 30th, 2026 [diff]

Executive Summary

• New PreModelSwitch and PostModelSwitch hooks let you block or confirm model switches before they happen, see their cache/cost impact, and inject model-specific guidance after a switch — documented across the hooks reference, hooks guide, and Agent SDK types.
• Cloud environments now support API credentials: keys or tokens an org admin stores on an environment that Anthropic's agent proxy attaches to matching requests without ever exposing them to Claude or the session's environment variables.
• A new desktopSessionCleanupPeriodDays setting lets you cap how long Claude Desktop and Cowork session transcripts are kept; previously they were retained indefinitely.
• Managed settings gained a documented recipe for turning off Anthropic telemetry org-wide via DISABLE_TELEMETRY, including why it's needed even under customer-managed encryption keys.
• Auto mode now turns off immediately in a running session when an admin-deployed policy disables it, instead of waiting until the session ends.

Claude Code changes

Changed documents

admin-setup [Source]

• Server-managed settings are now fetched at session startup, not just at authentication time, in addition to the hourly refresh. [line 43] [Source]
• Clarified what the WSL /status "Setting sources" line actually tells you: it always shows "Enterprise managed settings (remote)" once any server-managed keys arrive, so it doesn't confirm a Windows registry/file deployment in that case — only in sessions that aren't fetching server-managed settings. [lines 62-65] [Source]

agent-sdk/hooks [Source]

• Added PreModelSwitch and PostModelSwitch to the SDK hooks table, along with their timeout defaults (30 seconds) and blocking behavior. [line 163] [Source]

agent-sdk/modifying-system-prompts [Source]

• Clarified that keep-coding-instructions in an output style's frontmatter only has an effect on Claude Code's full system prompt — it does nothing when a session uses the shorter system prompt via CLAUDE_CODE_SIMPLE_SYSTEM_PROMPT. [line 106] [Source]

agent-sdk/typescript [Source]

• Added PreModelSwitchHookInput and PostModelSwitchHookInput types, plus the new "PreModelSwitch"/"PostModelSwitch" hook event names and their SyncHookJSONOutput variants (permissionDecision for pre-switch, additionalContext for post-switch). [lines 1645-1966] [Source]

claude-code-on-the-web [Source]

• Split the "Credential protection" bullet into two: one for git/signing credentials, and a new one describing the cloud environment API credentials feature, which keeps API keys outside the sandbox and attaches them to matching requests via a proxy. [lines 265-266] [Source]

claude-directory [Source]

• Documented that Claude Desktop and Cowork session transcripts are kept indefinitely by default, with a new desktopSessionCleanupPeriodDays setting to give them an age limit (requires v2.1.248+). Previously these transcripts had no special-cased retention rule described here. [lines 205-209] [Source]
• The retention-sweep pause condition now also triggers when desktopSessionCleanupPeriodDays is explicitly set and settings have validation errors. [line 234] [Source]
• Added desktopSessionCleanupPeriodDays to the list of ways to reduce credential-exposure risk from unencrypted transcripts. [line 235] [Source]

cloud-environments [Source]

• New Add API credentials section: org admins can store an API key/token (Bearer or other auth type) on a cloud environment, scoped to specific hosts; Anthropic's agent proxy attaches it to matching requests after they leave the session's VM, so Claude and its commands never see the value. Covers requirements (admin role, Anthropic-hosted environment, no customer-managed encryption keys), how to add one, and the requests that never get a credential (GitHub, the Anthropic API, and public package registries). [lines 36-91] [Source]
• API-credential hosts are now reachable regardless of the environment's network access level, alongside GitHub and MCP connector traffic. [lines 169-174] [Source]
• The "what carries over" table now says static API keys/tokens are supported, via API credentials, reversing the previous "no dedicated secrets store" guidance. [line 235] [Source]
• Shared (org-wide) environments can now also be edited from the environment selector at claude.ai/code by an Admin or Owner, not only from the admin Cloud environments page. [line 108] [Source]

commands [Source]

• Expanded the /terminal-setup description: it now also covers enabling Option+Enter and disabling the audible bell in Apple Terminal, and enabling clipboard access for /copy in iTerm2. [line 130] [Source]

data-usage [Source]

• Noted that Claude Desktop/Cowork transcripts are exempt from the 30-day local caching limit by default. [line 44] [Source]

discover-plugins [Source]

• Clarified that in cloud sessions, Claude Code doesn't start plugin language servers, so the LSP tool isn't available there even with a code-intelligence plugin installed. [line 44] [Source]

env-vars [Source]

• DISABLE_TELEMETRY entry now links to the new "Turn telemetry off for your organization" section in managed settings. [line 397] [Source]

glossary [Source]

• Trimmed the "Output style" entry to drop the detail about which built-in styles keep coding instructions by default, now covered on the dedicated output-styles/system-prompts pages. [line 163] [Source]

hooks [Source]

• Full reference sections added for the new PreModelSwitch and PostModelSwitch hook events (requires v2.1.251+): what triggers each, matcher rules against the target model's canonical name, input schema (from_model, to_model, requested_model, source, context_tokens, prompt_cache_warm, cache_ttl, estimated_cache_write_usd, pricing), and decision control — PreModelSwitch can allow/deny/ask (with ask only honored by an interactive /model), and a timed-out PreModelSwitch hook blocks the switch by default (unlike most other events). PostModelSwitch can only add additionalContext for Claude's next request. [lines 173-363] [Source]
• Added PreModelSwitch/PostModelSwitch to the lifecycle diagram, event summary table, matcher-value table, timeout-default text, exit-code-0 exceptions, exit-code-2 table, and the command/http/mcp_tool-only hook-type list. [lines 15-134] [Source]
• SessionStart hooks resuming or forking a transcript with at least one prior response now also receive seconds_since_last_response, context_tokens, prompt_cache_likely_expired, and estimated_cache_write_usd, letting a hook report the cost of resuming a stale conversation (requires v2.1.251+). [lines 141-166] [Source]

hooks-guide [Source]

• Added PreModelSwitch/PostModelSwitch to the event list, the exit-code-0 context-injection list, the matcher-field table, and the timeout-defaults text; also summarized PreModelSwitch's permissionDecision semantics. [lines 479-889] [Source]

managed-settings [Source]

• New "Turn telemetry off for your organization" section: deliver DISABLE_TELEMETRY: "1" through the managed env block to disable telemetry org-wide without relying on each developer's shell; explains it's applied without the approval dialog and also disables feature-flag fetching (Remote Control, default auto mode, etc.). [lines 298-311] [Source]

monitoring-usage [Source]

• Added transcripts_exempted_desktop to the retention_sweep event fields, counting transcripts kept under the new Claude Desktop/Cowork retention rule (requires v2.1.248+). [line 1051] [Source]

permission-modes [Source]

• A running session now exits auto mode immediately once an admin-deployed disableAutoMode policy reaches it, showing "auto mode disabled by settings"; before v2.1.251, a running session kept auto mode until it ended. [line 233] [Source]

plugins-reference [Source]

• Added PreModelSwitch/PostModelSwitch to the plugin hooks lifecycle-event table. [line 123] [Source]

prompt-caching [Source]

• Noted that a PreModelSwitch hook can require or skip the /model cache-warm confirmation prompt. [line 66] [Source]
• Removed the description of the LSP tool being "sticky" for the rest of a session once a language server becomes available (the tools-reference page now describes simpler behavior). [lines 103-107] [Source]

routines [Source]

• Routines no longer require "Claude Code on the web" to be separately enabled — available to all Pro/Max/Team/Enterprise users. [line 13] [Source]
• Routine environment variables guidance now points to the new API credentials feature instead of just warning not to add secrets. [line 61] [Source]

server-managed-settings [Source]

• Invalid cleanupPeriodDays and desktopSessionCleanupPeriodDays values are now kept in the cached remote-settings copy (but never applied) rather than stripped, and a payload consisting only of those invalid retention keys no longer causes a full payload rejection. [line 168] [Source]

sessions [Source]

• /clear can now take a name argument (e.g. /clear release-prep) to name the conversation you're leaving instead of carrying its name to the new one. [line 171] [Source]
• Added desktopSessionCleanupPeriodDays to the storage-configuration table. [line 207] [Source]

settings-reference [Source]

• Documented the new desktopSessionCleanupPeriodDays setting (user or managed scope, default 0 = no age limit; ignored when managed cleanupPeriodDays is set; requires v2.1.248+). [lines 5021-5036] [Source]
• Page now describes an interactive filter/sort UI (topic and scope dropdowns, sort-by control, settings count) above the settings table. [lines 3-11] [Source]

skills [Source]

• The /skills menu now saves a skill-visibility override with Esc, not Enter. [line 685] [Source]

third-party-integrations [Source]

• New note: customer-managed encryption keys (CMEK) don't cover Claude Code's operational telemetry when routing through an LLM gateway or custom ANTHROPIC_BASE_URL, so those orgs should use DISABLE_TELEMETRY via managed settings if they want it off. [line 50] [Source]

tools-reference [Source]

• Simplified the LSP tool's activation behavior description and added that it stays inactive in cloud sessions, since plugin language servers don't start there. [lines 268-269] [Source]

web-quickstart [Source]

• New troubleshooting entry: if /web-setup warns your GitHub CLI token lacks the workflow scope, some pushes (e.g. to GitHub Actions workflow files) may be rejected; fix with gh auth refresh -s workflow. [lines 203-205] [Source]

API changes

No changes to the Claude API documentation today.