How Claude Code uses prompt caching

 
 ### Enabling or disabling a plugin
 
-[Plugins](/docs/en/plugins) bundle several component types, and the cost of a change depends on which components the plugin provides. Skills, commands, agents, hooks, LSP servers, monitors, and themes never invalidate the cache: anything they add to the request is appended after the existing conversation, so the next request pays for the new content but still reads everything before it from the cache.
+When you enable or disable a [plugin](/docs/en/plugins), what the change costs depends on which component types the plugin provides. The cases below cover each component type, when Claude Code applies the change, and what happens when you disable a plugin again in the same session.
 
-The exception is a plugin that provides [MCP servers](/docs/en/plugins-reference#mcp-servers). Enabling or disabling one follows the same rules as [connecting or disconnecting an MCP server](#connecting-or-disconnecting-an-mcp-server): the cache survives when the server's tools are deferred, and the next request re-reads the entire conversation when they load into the prefix.
+#### Plugin components that keep the cache
 
-Plugin changes apply when you run [`/reload-plugins`](/docs/en/discover-plugins#apply-plugin-changes-without-restarting) or start a new session. For a plugin with a `command` source, Claude Code [can reload the plugin itself](/docs/en/plugin-marketplaces#when-claude-code-re-runs-the-command). Claude Code can also activate a plugin you [install from the `/plugin` interface](/docs/en/discover-plugins#install-plugins) during the install; the install summary tells you whether it did or whether to run `/reload-plugins`. If that reload would trigger the full re-read below, the command warns first and applies when you rerun it with `--force`.
+Claude Code never invalidates the cache for a plugin's skills, commands, agents, hooks, monitors, or themes. It appends their content after the existing conversation, so the next request pays for that content and still reads everything before it from the cache.
 
-The cost, whether appended announcements or a full re-read, shows up on the first turn after the change applies, not when you run `/plugin enable` or `/plugin disable`. When a reload would trigger the full re-read, `/reload-plugins` shows a warning and doesn't apply the reload. Pass `--force` to apply anyway.
+#### Plugins that provide MCP servers
 
-Disabling a plugin you enabled earlier in the session restores the previous request shape. If that prefix is still within its [cache lifetime](#cache-lifetime), the next request reads the older cache entry instead of rebuilding.
+When you enable or disable a plugin that provides [MCP servers](/docs/en/plugins-reference#mcp-servers), Claude Code follows the same rules as when you [connect or disconnect an MCP server](#connecting-or-disconnecting-an-mcp-server):
+
+* If Claude Code defers the server's tools, it keeps the cache.
+* If Claude Code loads them into the prefix, the next request re-reads the entire conversation.
+
+#### Code intelligence plugins
+
+When you enable a [code intelligence plugin](/docs/en/discover-plugins#code-intelligence), Claude gets the [LSP tool](/docs/en/tools-reference#lsp-tool-behavior).
+
+If you enable one mid-session, Claude Code changes the tool set at most once in that session. Once Claude Code has had a language server available, it keeps the LSP tool in the request for the rest of the session. Claude Code doesn't change the tool set or invalidate the cache when a language server stops, fails, or reconnects later. Before v2.1.235, Claude Code removed the tool from the request whenever every language server had crashed or failed to start and added it back when one recovered.
+
+#### When plugin changes apply
+
+Claude Code applies a plugin change when you run [`/reload-plugins`](/docs/en/discover-plugins#apply-plugin-changes-without-restarting) or start a new session. You pay the cost, whether appended announcements or a full re-read, on the first turn after the change applies, not when you run `/plugin enable` or `/plugin disable`. Claude Code can also apply a change on its own in two cases:
+
+* For a plugin with a `command` source, Claude Code [can reload the plugin itself](/docs/en/plugin-marketplaces#when-claude-code-re-runs-the-command).
+* When you [install a plugin from the `/plugin` interface](/docs/en/discover-plugins#install-plugins), Claude Code can activate it during the install. Claude Code tells you in the install summary whether it did or whether to run `/reload-plugins`.
+
+When you run `/reload-plugins` and the reload would trigger a full re-read, Claude Code shows a warning and doesn't apply the reload. Rerun it with `--force` to apply the reload anyway.
+
+#### Plugins you enable and then disable in one session
+
+When you disable a plugin you enabled earlier in the session, Claude Code restores the previous request shape, apart from the [LSP tool](#code-intelligence-plugins), which Claude Code keeps for the rest of the session. If that prefix is still within its [cache lifetime](#cache-lifetime), the next request reads the older cache entry instead of rebuilding.
 
 ### Denying an entire tool