diff --git a/CLAUDE.md b/CLAUDE.md
index d234de1..d5c14a9 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -6,7 +6,7 @@ Transcript-based shell integration test runner. Bun + TypeScript.
 
 - `bun test` — run unit tests
 - `bunx tsc --noEmit` — type check
-- `bun run src/cli/index.ts test [files...]` — run shout CLI
+- `bun run src/cli/index.ts [files...]` — run shout CLI (`--port-from <n>` auto-assigns `$PORT`)
 
 ## Architecture
 
@@ -28,6 +28,8 @@ Transcript-based shell integration test runner. Bun + TypeScript.
 - `[N]` on last line of expected output = assert exit code N
 - `[*]` = assert any non-zero exit code; default expects 0
 - `#` after a command = comment (stripped); `#` in expected output is literal
+- `@env KEY=VALUE` before first command = set environment variable
+- `@setup path.shout` before first command = prepend commands (and `@env`) from another file
 - Each file runs in a fresh temp dir with a single `/bin/sh` session
 
 ## Style
diff --git a/src/cli/index.ts b/src/cli/index.ts
index 2a5e8ce..0bbc63b 100755
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -1,11 +1,11 @@
 #!/usr/bin/env bun
 
 import { readdir, readFile, writeFile } from "node:fs/promises"
-import { resolve, relative } from "node:path"
+import { resolve, relative, dirname } from "node:path"
 import { program } from "commander"
 import ansis from "ansis"
 
-import { parse } from "../parse.ts"
+import { parse, type Command, type ShoutFile } from "../parse.ts"
 import { runFile, cleanupTmpDir } from "../run.ts"
 import { evaluateFile, formatFailure, formatSummary } from "../format.ts"
 import type { TestResult } from "../format.ts"
@@ -60,6 +60,7 @@ program
   .option("--path <path>", "Prepend <path> to PATH (repeatable)", (val: string, acc: string[]) => [...acc, val])
   .option("--timeout <dur>", "Per-command timeout", "10s")
   .option("-v, --verbose", "Print each command as it runs")
+  .option("--port-from <n>", "Auto-assign $PORT starting from <n>")
   .option("--parallel", "Run files in parallel")
   .action(async (fileArgs: string[], opts) => {
     const timeoutMs = parseDuration(opts.timeout)
@@ -74,14 +75,49 @@ program
     const start = performance.now()
     const results: TestResult[] = []
     const cwd = process.cwd()
+    const portFrom = opts.portFrom ? parseInt(opts.portFrom, 10) : undefined
+    if (portFrom !== undefined && Number.isNaN(portFrom)) {
+      console.error("--port-from must be an integer")
+      process.exit(1)
+    }
+    let nextPort = portFrom
 
-    const runOne = async (filePath: string) => {
+    const runOne = async (filePath: string, port: number | undefined) => {
       const content = await readFile(filePath, "utf-8")
       const parsed = parse(relative(cwd, filePath), content)
 
-      const fileResult = await runFile(parsed, {
+      // Resolve directives in a single pass. Setup @env is collected separately
+      // so that the user file's @env always takes precedence.
+      const envVars: Record<string, string> = {}
+      const setupEnvVars: Record<string, string> = {}
+      const userEnvVars: Record<string, string> = {}
+      const setupCommands: Command[] = []
+      for (const d of parsed.directives) {
+        if (d.type === "setup") {
+          const setupPath = resolve(dirname(filePath), d.path)
+          const setupContent = await readFile(setupPath, "utf-8")
+          const setupParsed = parse(relative(cwd, setupPath), setupContent)
+          for (const sd of setupParsed.directives) {
+            if (sd.type === "setup") {
+              throw new Error(`${relative(cwd, setupPath)}: @setup not allowed in setup files`)
+            }
+            if (sd.type === "env") setupEnvVars[sd.key] = sd.value
+          }
+          setupCommands.push(...setupParsed.commands)
+        } else if (d.type === "env") {
+          userEnvVars[d.key] = d.value
+        }
+      }
+      Object.assign(envVars, setupEnvVars, userEnvVars)
+      if (port !== undefined && !("PORT" in userEnvVars) && !("PORT" in setupEnvVars)) {
+        envVars["PORT"] = String(port)
+      }
+      const merged: ShoutFile = { ...parsed, commands: [...setupCommands, ...parsed.commands] }
+
+      const fileResult = await runFile(merged, {
         cleanEnv: opts.cleanEnv ?? false,
         pathDirs: opts.path,
+        envVars,
         timeout: timeoutMs,
         verbose: opts.verbose ?? false,
         onCommand: opts.verbose
@@ -89,14 +125,39 @@ program
           : undefined,
       })
 
+      // Check setup commands for failures
+      for (let i = 0; i < setupCommands.length; i++) {
+        const r = fileResult.results[i]
+        const expected = setupCommands[i]!.exitCode
+        const ok = expected === null
+          ? r?.exitCode === 0
+          : expected === "*"
+            ? r?.exitCode !== 0
+            : r?.exitCode === expected
+        if (!ok) {
+          if (opts.keep) {
+            process.stderr.write(`${fileResult.tmpDir}\n`)
+          } else {
+            await cleanupTmpDir(fileResult.tmpDir)
+          }
+          return evaluateFile(
+            parsed.path,
+            [],
+            `setup command failed (exit ${r?.exitCode ?? "?"}): $ ${setupCommands[i]!.command}`,
+          )
+        }
+      }
+
+      const fileOwnResults = fileResult.results.slice(setupCommands.length)
+
       const testResult = evaluateFile(
         parsed.path,
-        fileResult.results,
+        fileOwnResults,
         fileResult.error,
       )
 
-      if (opts.update && fileResult.results.length > 0) {
-        const updated = rewriteFile(parsed, fileResult.results, content)
+      if (opts.update && fileOwnResults.length > 0) {
+        const updated = rewriteFile(parsed, fileOwnResults, content)
         if (updated !== content) {
           await writeFile(filePath, updated)
         }
@@ -126,7 +187,7 @@ program
     }
 
     if (opts.parallel) {
-      const all = await Promise.all(files.map(runOne))
+      const all = await Promise.all(files.map(f => runOne(f, nextPort !== undefined ? nextPort++ : undefined)))
       for (const r of all) {
         printDots(r)
         results.push(r)
@@ -134,7 +195,7 @@ program
       process.stdout.write("\n")
     } else {
       for (const filePath of files) {
-        const r = await runOne(filePath)
+        const r = await runOne(filePath, nextPort !== undefined ? nextPort++ : undefined)
         printDots(r)
         results.push(r)
       }
diff --git a/src/index.ts b/src/index.ts
index 107ee68..29281a8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,4 @@
-export type { Command, ShoutFile } from "./parse.ts"
+export type { Command, Directive, ShoutFile } from "./parse.ts"
 export type { CommandResult, FileResult } from "./run.ts"
 export type { DiffLine } from "./match.ts"
 export type { TestResult } from "./format.ts"
diff --git a/src/parse.test.ts b/src/parse.test.ts
index 87712ec..70a28f7 100644
--- a/src/parse.test.ts
+++ b/src/parse.test.ts
@@ -66,4 +66,53 @@ describe("parse", () => {
     const b = parse("test.shout", "$ echo hi\nhi")
     expect(a.commands[0]!.expected).toEqual(b.commands[0]!.expected)
   })
+
+  test("@env directive", () => {
+    const result = parse("test.shout", "@env PORT=3000\n$ echo $PORT\n3000\n")
+    expect(result.directives).toEqual([
+      { type: "env", key: "PORT", value: "3000", line: 1 },
+    ])
+    expect(result.commands).toHaveLength(1)
+  })
+
+  test("@env with value containing =", () => {
+    const result = parse("test.shout", "@env FOO=bar=baz\n$ echo $FOO\n")
+    expect(result.directives[0]).toEqual(
+      { type: "env", key: "FOO", value: "bar=baz", line: 1 },
+    )
+  })
+
+  test("@setup directive", () => {
+    const result = parse("test.shout", "@setup shared/setup.shout\n$ echo hi\nhi\n")
+    expect(result.directives).toEqual([
+      { type: "setup", path: "shared/setup.shout", line: 1 },
+    ])
+    expect(result.commands).toHaveLength(1)
+  })
+
+  test("multiple directives", () => {
+    const content = "@setup setup.shout\n@env PORT=3000\n@env NODE_ENV=test\n\n$ echo hi\nhi\n"
+    const result = parse("test.shout", content)
+    expect(result.directives).toHaveLength(3)
+    expect(result.directives[0]!.type).toBe("setup")
+    expect(result.directives[1]).toEqual({ type: "env", key: "PORT", value: "3000", line: 2 })
+    expect(result.directives[2]).toEqual({ type: "env", key: "NODE_ENV", value: "test", line: 3 })
+  })
+
+  test("@ lines after first command are expected output", () => {
+    const result = parse("test.shout", "$ cat config\n@env PORT=3000\n")
+    expect(result.directives).toEqual([])
+    expect(result.commands[0]!.expected).toEqual(["@env PORT=3000"])
+  })
+
+  test("no directives returns empty array", () => {
+    const result = parse("test.shout", "$ echo hi\nhi\n")
+    expect(result.directives).toEqual([])
+  })
+
+  test("unknown directive throws", () => {
+    expect(() => parse("test.shout", "@evn PORT=3000\n$ echo hi\n")).toThrow(
+      "test.shout:1: unknown directive: @evn PORT=3000",
+    )
+  })
 })
diff --git a/src/parse.ts b/src/parse.ts
index d204ca4..94cb20c 100644
--- a/src/parse.ts
+++ b/src/parse.ts
@@ -6,9 +6,14 @@ export type Command = {
   exitCode: number | "*" | null
 }
 
+export type Directive =
+  | { type: "setup"; path: string; line: number }
+  | { type: "env"; key: string; value: string; line: number }
+
 export type ShoutFile = {
   path: string
   commands: Command[]
+  directives: Directive[]
 }
 
 function stripComment(line: string): string {
@@ -58,12 +63,35 @@ export function parse(path: string, content: string): ShoutFile {
   }
 
   const commands: Command[] = []
+  const directives: Directive[] = []
   let current: Command | null = null
+  let seenCommand = false
 
   for (let i = 0; i < rawLines.length; i++) {
     const line = rawLines[i]!
 
+    if (!seenCommand && line.startsWith("@")) {
+      if (line.startsWith("@setup ")) {
+        const setupPath = line.slice(7).trim()
+        if (!setupPath) {
+          throw new Error(`${path}:${i + 1}: @setup requires a file path`)
+        }
+        directives.push({ type: "setup", path: setupPath, line: i + 1 })
+      } else if (line.startsWith("@env ")) {
+        const rest = line.slice(5).trim()
+        const eq = rest.indexOf("=")
+        if (eq <= 0) {
+          throw new Error(`${path}:${i + 1}: malformed @env directive (expected KEY=VALUE): ${line}`)
+        }
+        directives.push({ type: "env", key: rest.slice(0, eq), value: rest.slice(eq + 1), line: i + 1 })
+      } else {
+        throw new Error(`${path}:${i + 1}: unknown directive: ${line}`)
+      }
+      continue
+    }
+
     if (line.startsWith("$ ")) {
+      seenCommand = true
       if (current) {
         const trimmed = trimTrailingEmpty(current.expected)
         const { lines: expectedLines, exitCode } = parseExitCode(trimmed)
@@ -92,5 +120,5 @@ export function parse(path: string, content: string): ShoutFile {
     commands.push(current)
   }
 
-  return { path, commands }
+  return { path, commands, directives }
 }
diff --git a/src/run.ts b/src/run.ts
index b26fd38..516f0e5 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -20,6 +20,7 @@ export type FileResult = {
 type RunOptions = {
   cleanEnv: boolean
   pathDirs?: string[]
+  envVars?: Record<string, string>
   timeout: number
   verbose: boolean
   onCommand?: (cmd: Command) => void
@@ -128,6 +129,10 @@ export async function runFile(
   env["HOME"] = tmpDir
   env["SHOUT_DIR"] = tmpDir
 
+  if (options.envVars) {
+    Object.assign(env, options.envVars)
+  }
+
   if (options.pathDirs?.length) {
     env["PATH"] = options.pathDirs.join(":") + ":" + (env["PATH"] ?? "")
   }
diff --git a/test/env.shout b/test/env.shout
new file mode 100644
index 0000000..245d02c
--- /dev/null
+++ b/test/env.shout
@@ -0,0 +1,5 @@
+@env GREETING=hello
+@env TARGET=world
+
+$ echo "$GREETING $TARGET"
+hello world
diff --git a/test/setup-shared.shout b/test/setup-shared.shout
new file mode 100644
index 0000000..7ad3eba
--- /dev/null
+++ b/test/setup-shared.shout
@@ -0,0 +1 @@
+$ export READY=yes
diff --git a/test/setup-user.shout b/test/setup-user.shout
new file mode 100644
index 0000000..023c5c2
--- /dev/null
+++ b/test/setup-user.shout
@@ -0,0 +1,4 @@
+@setup setup-shared.shout
+
+$ echo $READY
+yes