> ## Documentation Index
> Fetch the complete documentation index at: https://docs.themcp.company/llms.txt
> Use this file to discover all available pages before exploring further.

# Automatic SDK patching

> How mcp-tap intercepts AI SDK calls automatically

When `init()` is called, mcp-tap monkey-patches each supported SDK. If a library isn't installed, its patch is silently skipped. Patches never raise exceptions or affect application behavior.

## Supported SDKs

| SDK                  | TypeScript                  | Python      | What's patched                                     |
| -------------------- | --------------------------- | ----------- | -------------------------------------------------- |
| **Anthropic**        | `@anthropic-ai/sdk`         | `anthropic` | `Messages.create` (sync + async in Python)         |
| **OpenAI**           | `openai`                    | `openai`    | `Chat.Completions.create` (sync + async in Python) |
| **MCP Client**       | `@modelcontextprotocol/sdk` | `mcp`       | `Client.callTool` / `ClientSession.call_tool`      |
| **Composio**         | `composio-core`             | `composio`  | `ComposioToolSet.executeAction` / `execute_action` |
| **HTTP (catch-all)** | `globalThis.fetch`          | `httpx`     | Requests to known AI API hosts                     |

## What gets captured

For **LLM requests** (Anthropic, OpenAI, HTTP), mcp-tap emits an `llm_request` parent event with:

* Model name, system prompt, request messages, response content
* Token usage (input/output/cache tokens)
* Thinking/reasoning blocks (if present)
* Stop reason
* Latency

For each **tool call** in the response, a child `tool_call` event is emitted with the tool name and input arguments, linked to the parent via `parent_event_id`.

For **MCP and Composio** calls, a `tool_call` event is emitted with tool name, inputs, output, error (if any), and latency.

## Individual patch functions

Each patch can be applied independently if you don't want `init()` to patch everything:

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { patchAnthropic, patchOpenAI, patchMCP, patchComposio, patchHTTP } from "mcp-tap";

  patchAnthropic();  // Patches @anthropic-ai/sdk Messages.create
  patchOpenAI();     // Patches openai Chat.Completions.create
  patchMCP();        // Patches @modelcontextprotocol/sdk Client.callTool
  patchComposio();   // Patches composio-core ComposioToolSet.executeAction
  patchHTTP();       // Patches globalThis.fetch for known AI hosts
  ```
</CodeGroup>

## Double-counting prevention

When both an SDK patch and the HTTP patch are active, the SDK patch marks a flag (`_inSdkPatch` in TypeScript, `mark_sdk_patch()` in Python) during execution. The HTTP patch checks this flag and skips interception when it's set, preventing the same call from being logged twice.