diff --git a/docs/src/content/docs/reference/engines.md b/docs/src/content/docs/reference/engines.md
index e21f302415..4d07809b53 100644
--- a/docs/src/content/docs/reference/engines.md
+++ b/docs/src/content/docs/reference/engines.md
@@ -86,6 +86,7 @@ engine:
   id: copilot
   version: latest                       # defaults to latest
   model: gpt-5                          # defaults to claude-sonnet-4
+  command: /usr/local/bin/copilot       # custom executable path
   args: ["--add-dir", "/workspace"]     # custom CLI arguments
   agent: agent-id                       # custom agent file identifier
 ```
@@ -131,6 +132,19 @@ engine:
 
 Arguments are added in order and placed before the `--prompt` flag. Common uses include adding directories (`--add-dir`), enabling verbose logging (`--verbose`, `--debug`), and passing engine-specific flags. Consult the specific engine's CLI documentation for available flags.
 
+### Custom Engine Command
+
+Override the default engine executable using the `command` field. Useful for testing pre-release versions, custom builds, or non-standard installations. Installation steps are automatically skipped.
+
+```yaml wrap
+engine:
+  id: copilot
+  command: /usr/local/bin/copilot-dev  # absolute path
+  args: ["--verbose"]
+```
+
+The command supports absolute paths (`/usr/local/bin/copilot`), relative paths (`./bin/claude`), environment variables (`$HOME/.local/bin/codex`), or commands in PATH.
+
 ## Related Documentation
 
 - [Frontmatter](/gh-aw/reference/frontmatter/) - Complete configuration reference