feat(ai-conversations): add conversations docs page

Author: obostjancic

docs/ai/monitoring/conversations/index.mdx

@@ -0,0 +1,92 @@
+---
+title: Conversations
+sidebar_order: 15
+new: true
+description: >-
+  Monitor past conversations with your AI assistants. Replay every message and
+  tool call to understand what happened and where things went wrong.
+keywords:
+  - AI conversations
+  - conversation monitoring
+  - chat monitoring
+  - gen_ai.conversation.id
+  - conversation tracking
+  - LLM conversations
+---
+
+Sentry's Conversations view lets you observe the interactions users have had with your chat-based AI assistants. It provides a user-like view into past conversations, showing the full exchange of messages and tool calls so you can understand exactly what happened during each session.
+
+## Prerequisites
+
+Conversations are built on top of [AI Agent Monitoring](/ai/monitoring/agents/). Before you can use them, you need:
+
+1. **Tracing enabled** with the Sentry SDK configured for your AI agent project. Follow the [Agent Monitoring getting started guide](/ai/monitoring/agents/getting-started/) if you haven't already.
+
+2. **A conversation ID on your spans.** Sentry groups spans into conversations using the `gen_ai.conversation.id` attribute. You can set this manually, or some SDK integrations infer it automatically.
+
+## Setting the Conversation ID
+
+A conversation is a collection of spans that share the same `gen_ai.conversation.id`. This is typically the ID of the chat session in your application (for example, the session ID you store in your database).
+
+### Auto-Instrumented
+
+The following integrations automatically infer the conversation ID from the underlying AI SDK:
+
+- **OpenAI Agents SDK** (Python)
+- **OpenAI SDK** (Node)
+
+If you're using one of these, no additional setup is needed.
+
+### Manual
+
+For all other integrations, set the conversation ID at the start of each conversation:
+
+```python
+import sentry_sdk
+
+# Call this at the start of each conversation
+sentry_sdk.ai.set_conversation_id("my-conversation-123")
+```
+
+```javascript
+import * as Sentry from "@sentry/node";
+
+// Call this at the start of each conversation
+Sentry.setConversationId("my-conversation-123");
+```
+
+Use whatever identifier your application already uses for the chat session. All spans created after calling this method will be tagged with the given conversation ID.
+
+### Conversations and Traces
+
+Conversations and traces are independent concepts. A single conversation can span multiple traces. For example, if a user refreshes the page mid-conversation, the browser starts a new trace, but the conversation continues with the same ID.
+
+The reverse is also true: a single trace can contain spans from different conversations. For example, if a user starts a new chat session without refreshing the page, the new conversation's spans appear in the same trace as the previous one.
+
+## Conversations List
+
+The [Conversations](https://sentry.io/orgredirect/organizations/:orgslug/insights/ai/conversations/) page shows the most recent conversations that match your filters.
+
+<!-- TODO: Add screenshot of conversations list -->
+<!-- ![Conversations List](./img/conversations-list.png) -->
+
+Each row in the list displays:
+
+- **First input** — the first user message in the conversation
+- **Last output** — the most recent assistant response
+- **Cost** — estimated dollar cost and token usage
+- **LLM calls** — number of LLM generation requests
+- **Tool calls** — number of tool executions
+
+Use the filters at the top of the page to narrow results by project, date range, or agent.
+
+## Conversation Detail
+
+Click any conversation to open the detail view in a drawer.
+
+<!-- TODO: Add screenshot of conversation detail drawer -->
+<!-- ![Conversation Detail](./img/conversation-detail.png) -->
+
+The detail view shows a chat-like interface with the full message history: user inputs, assistant responses, and tool calls. Click on any message to see the underlying spans, including individual LLM generations and tool executions, with timing and error information.
+
+This makes it straightforward to trace a conversation from start to finish and pinpoint where things went wrong.

docs/ai/monitoring/index.mdx

@@ -22,6 +22,13 @@ Sentry provides comprehensive monitoring for your AI implementations. Whether yo
     description="Monitor AI agent workflows including agent runs, tool calls, model interactions, and handoffs."
     className="w-full md:w-[calc(50%-12px)]"
   />
+  <LinkCard
+    href="/ai/monitoring/conversations/"
+    iconSrc="/ai/img/IconCompass.svg"
+    title="Conversations"
+    description="Replay past conversations with your AI assistants. See every message and tool call in a chat-like view."
+    className="w-full md:w-[calc(50%-12px)]"
+  />
   <LinkCard
     href="/ai/monitoring/mcp/"
     iconSrc="/ai/img/IconCode.svg"