docs: Claude Authentication (#37573)

Release Notes:

- N/A

docs/src/ai/agent-panel.md

@@ -23,7 +23,7 @@ From this point on, you can interact with the many supported features outlined b
 
 > Note that for external agents, like [Gemini CLI](./external-agents.md#gemini-cli) or [Claude Code](./external-agents.md#claude-code), some of the features outlined below are _not_ currently supported—for example, _restoring threads from history_, _checkpoints_, _token usage display_, _model selection_, and others. All of them should hopefully be supported in the future.
 
-### Creating New Threads
+### Creating New Threads {#new-thread}
 
 By default, the Agent Panel uses Zed's first-party agent.
 

docs/src/ai/external-agents.md

@@ -85,6 +85,12 @@ If you'd like to bind this to a keyboard shortcut, you can do so by editing your
 ]
 ```
 
+### Authentication
+
+As of version `0.202.7` (stable) and `0.203.2` (preview), authentication to Zed's Claude Code installation is decoupled entirely from Zed's agent. That is to say, an Anthropic API key added via the [Zed Agent's settings](./llm-providers.md#anthropic) will _not_ be utilized by Claude Code for authentication and billing.
+
+To ensure you're using your billing method of choice, [open a new Claude Code thread](./agent-panel.md#new-thread)`. Then, run `/login`, and authenticate either via API key, or via `Log in with Claude Code` to use a Claude Pro/Max subscription.
+
 #### Installation
 
 The first time you create a Claude Code thread, Zed will install [@zed-industries/claude-code-acp](https://github.com/zed-industries/claude-code-acp). This installation is only available to Zed and is kept up to date as you use the agent.