diff --git a/CLAUDE.md b/CLAUDE.md
index 81216eb..22912ea 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -45,6 +45,8 @@ Transcript-based shell integration test runner. Bun + TypeScript.
   - Setup command failures abort the test with an error
 - Each file runs in a fresh temp dir with a single `/bin/sh` session
 - `$HOME` and `$SHOUT_DIR` are set to the temp dir automatically
+- `$SHOUT_SOURCE_DIR` is set to the directory containing the `.shout` file
+- `$SHOUT_PROJECT_DIR` is set to `cwd` where `shout` was invoked
 - stdout and stderr are merged (`exec 2>&1`)
 
 ## Style
diff --git a/src/cli/index.ts b/src/cli/index.ts
index 2c3a72a..63e4c63 100755
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -134,6 +134,8 @@ program
         cleanEnv: opts.cleanEnv ?? false,
         pathDirs: opts.path,
         envVars,
+        sourceDir: resolve(dirname(filePath)),
+        projectDir: cwd,
         timeout: timeoutMs,
         verbose: opts.verbose ?? false,
         onCommand: opts.verbose
diff --git a/src/run.ts b/src/run.ts
index 8df05a7..a66968d 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -21,6 +21,8 @@ type RunOptions = {
   cleanEnv: boolean
   pathDirs?: string[]
   envVars?: Record<string, string>
+  sourceDir?: string
+  projectDir?: string
   timeout: number
   verbose: boolean
   onCommand?: (cmd: Command) => void
@@ -128,6 +130,12 @@ export async function runFile(
 
   env["HOME"] = tmpDir
   env["SHOUT_DIR"] = tmpDir
+  if (options.sourceDir) {
+    env["SHOUT_SOURCE_DIR"] = options.sourceDir
+  }
+  if (options.projectDir) {
+    env["SHOUT_PROJECT_DIR"] = options.projectDir
+  }
 
   if (options.envVars) {
     Object.assign(env, options.envVars)
diff --git a/web/index.html b/web/index.html
index 854a6a9..e42394b 100644
--- a/web/index.html
+++ b/web/index.html
@@ -237,8 +237,10 @@ Options:
   <h2>Environment</h2>
   <p>Shout sets these variables before running your commands:</p>
   <pre><code><span class="bright">HOME</span>      <span class="dim">→</span> <span class="output">temp directory for this test file</span>
-<span class="bright">SHOUT_DIR</span>   <span class="dim">→</span> <span class="output">same temp directory</span>
-<span class="bright">PATH</span>      <span class="dim">→</span> <span class="output">prepended with --path dirs, if any</span></code></pre>
+<span class="bright">SHOUT_DIR</span>      <span class="dim">→</span> <span class="output">same temp directory</span>
+<span class="bright">SHOUT_SOURCE_DIR</span>  <span class="dim">→</span> <span class="output">directory containing the .shout file</span>
+<span class="bright">SHOUT_PROJECT_DIR</span> <span class="dim">→</span> <span class="output">directory where shout was invoked</span>
+<span class="bright">PATH</span>           <span class="dim">→</span> <span class="output">prepended with --path dirs, if any</span></code></pre>
   <p>Each file runs in its own temp directory. <code>--clean-env</code> starts with an empty environment instead of inheriting yours.</p>
 </section>