docs: document the built in agents (#12066)

packages/opencode/src/provider/provider.ts

@@ -989,7 +989,7 @@ export namespace Provider {
 
         // Merge configured headers into request headers
         opts.headers = {
-          ...(typeof opts.headers === "object" ? opts.headers : {}),
+          ...(opts.headers ?? {}),
           ...options["headers"],
         }
 

packages/web/src/content/docs/agents.mdx

@@ -46,7 +46,7 @@ OpenCode comes with two built-in primary agents and two built-in subagents.
 
 ---
 
-### Build
+### Use build
 
 _Mode_: `primary`
 
@@ -54,7 +54,7 @@ Build is the **default** primary agent with all tools enabled. This is the stand
 
 ---
 
-### Plan
+### Use plan
 
 _Mode_: `primary`
 
@@ -68,7 +68,7 @@ This agent is useful when you want the LLM to analyze code, suggest changes, or
 
 ---
 
-### General
+### Use general
 
 _Mode_: `subagent`
 
@@ -76,7 +76,7 @@ A general-purpose agent for researching complex questions and executing multi-st
 
 ---
 
-### Explore
+### Use explore
 
 _Mode_: `subagent`
 
@@ -84,6 +84,30 @@ A fast, read-only agent for exploring codebases. Cannot modify files. Use this w
 
 ---
 
+### Use compaction
+
+_Mode_: `primary`
+
+Hidden system agent that compacts long context into a smaller summary. It runs automatically when needed and is not selectable in the UI.
+
+---
+
+### Use title
+
+_Mode_: `primary`
+
+Hidden system agent that generates short session titles. It runs automatically and is not selectable in the UI.
+
+---
+
+### Use summary
+
+_Mode_: `primary`
+
+Hidden system agent that creates session summaries. It runs automatically and is not selectable in the UI.
+
+---
+
 ## Usage
 
 1. For primary agents, use the **Tab** key to cycle through them during a session. You can also use your configured `switch_agent` keybind.