From 90757b9186a515aa11dba95c9c76f53cd0c98584 Mon Sep 17 00:00:00 2001
From: Chris <chris@example.com>
Date: Mon, 13 Jul 2026 15:43:46 -0500
Subject: [PATCH] docs: document automatic build arguments (GIT_SHA,
 BUILD_TIMESTAMP)

---
 docs/basics/02-projects/index.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/docs/basics/02-projects/index.md b/docs/basics/02-projects/index.md
index dbb8b6d..f9a4e8e 100644
--- a/docs/basics/02-projects/index.md
+++ b/docs/basics/02-projects/index.md
@@ -42,6 +42,26 @@ Navigate to **Project > Environment Variables** to manage configuration:
 
 You can download all environment variables as a `.env` file for local development.
 
+#### Automatic Build Arguments
+
+Canine automatically injects the following build arguments into every build:
+
+| Variable | Description |
+|----------|-------------|
+| `GIT_SHA` | The Git commit SHA being built |
+| `BUILD_TIMESTAMP` | UTC timestamp of when the build started (ISO 8601) |
+
+These are available as Docker build arguments. To use them at runtime, add the following to your Dockerfile:
+
+```dockerfile
+ARG GIT_SHA
+ARG BUILD_TIMESTAMP
+ENV GIT_SHA=$GIT_SHA
+ENV BUILD_TIMESTAMP=$BUILD_TIMESTAMP
+```
+
+For buildpack-based builds, these are automatically set as environment variables.
+
 ### Preview Apps
 
 When enabled, Canine automatically creates a temporary deployment for each pull request. See [Preview Apps](./04-preview-apps.md) for detailed configuration.