diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 0000000..66aa68b
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,11 @@
+## Summary
+
+Describe the change in 2-5 bullets.
+
+## Validation
+
+List the commands, checks, or CI evidence that validate this PR.
+
+## Notes
+
+Add any context that helps reviewers focus on the important details.
diff --git a/.github/workflows/ci-pr-checks.yml b/.github/workflows/ci-pr-checks.yml
new file mode 100644
index 0000000..a422a17
--- /dev/null
+++ b/.github/workflows/ci-pr-checks.yml
@@ -0,0 +1,72 @@
+name: "CI - PR Checks"
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize, reopened]
+
+permissions:
+  contents: read
+  pull-requests: read
+
+concurrency:
+  group: pr-checks-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  title:
+    name: PR title
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Check PR title
+        uses: zrr1999/zendev-actions/validate-title@9013ad848b32d287d0258fdbc9f51e350b8eca33
+        with:
+          text: ${{ github.event.pull_request.title }}
+
+  body:
+    name: PR body
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Check PR body headings
+        env:
+          GITHUB_EVENT_PATH: ${{ github.event_path }}
+        run: |
+          python - <<'PY'
+          import json
+          import os
+          import re
+          import sys
+          from pathlib import Path
+
+          def extract_h2_headings(text: str) -> list[str]:
+              in_fence = False
+              headings = []
+              for line in text.splitlines():
+                  stripped = line.strip()
+                  if stripped.startswith("```"):
+                      in_fence = not in_fence
+                      continue
+                  if in_fence:
+                      continue
+                  if re.match(r"^##\s+\S", stripped):
+                      headings.append(re.sub(r"^##\s+", "", stripped))
+              return headings
+
+          payload = json.loads(Path(os.environ["GITHUB_EVENT_PATH"]).read_text(encoding="utf-8"))
+          body = (payload.get("pull_request") or {}).get("body") or ""
+          template = Path(".github/pull_request_template.md").read_text(encoding="utf-8")
+
+          expected = extract_h2_headings(template)
+          actual = extract_h2_headings(body)
+
+          if actual != expected:
+              print("PR body headings do not match the repository template.", file=sys.stderr)
+              print(f"Expected headings: {expected}", file=sys.stderr)
+              print(f"Actual headings:   {actual}", file=sys.stderr)
+              raise SystemExit(1)
+
+          print("PR body headings match the repository template.")
+          PY
diff --git a/.github/workflows/ci-static-checks.yml b/.github/workflows/ci-static-checks.yml
new file mode 100644
index 0000000..299a51f
--- /dev/null
+++ b/.github/workflows/ci-static-checks.yml
@@ -0,0 +1,27 @@
+name: "CI - Static Checks"
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-static-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  prek:
+    name: prek
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          components: clippy, rustfmt
+
+      - uses: j178/prek-action@v2
diff --git a/.github/workflows/ci-tests.yml b/.github/workflows/ci-tests.yml
new file mode 100644
index 0000000..5a379eb
--- /dev/null
+++ b/.github/workflows/ci-tests.yml
@@ -0,0 +1,93 @@
+name: "CI - Tests"
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-tests-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  host:
+    name: host
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: host
+
+      - name: Build host crate
+        run: cargo build --manifest-path host/Cargo.toml
+
+      - name: Run host tests
+        run: cargo test --manifest-path host/Cargo.toml
+
+  spore:
+    name: spore
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/checkout@v6
+        with:
+          repository: spore-lang/spore
+          ref: ef627c785e355a70551af5e4f4d85230996ce8d9
+          path: _spore
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: _spore
+
+      - name: Build spore compiler
+        run: cargo build --release --manifest-path _spore/Cargo.toml --bin spore
+
+      - name: Format Spore files
+        run: |
+          paths=(examples platform)
+          if [ -d tests ]; then
+            paths+=(tests)
+          fi
+          find "${paths[@]}" -name '*.sp' -type f | sort | xargs _spore/target/release/spore format
+          git diff --exit-code -- "${paths[@]}"
+
+      - name: Check Spore files
+        run: |
+          paths=(examples platform)
+          if [ -d tests ]; then
+            paths+=(tests)
+          fi
+          find "${paths[@]}" -name '*.sp' -type f | sort | xargs -n 1 _spore/target/release/spore check
+
+      - name: Build Spore files
+        run: |
+          paths=(examples platform)
+          if [ -d tests ]; then
+            paths+=(tests)
+          fi
+          find "${paths[@]}" -name '*.sp' -type f | sort | xargs -n 1 _spore/target/release/spore build
+
+      - name: Run hello example
+        run: _spore/target/release/spore run examples/hello.sp
+
+      - name: Run Spore spec tests
+        run: |
+          if [ ! -d tests ]; then
+            echo "No Spore spec tests yet; skipping spore test."
+            exit 0
+          fi
+          find tests -name '*.sp' -type f | sort | xargs -r -n 1 _spore/target/release/spore test
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
deleted file mode 100644
index c2f226e..0000000
--- a/.github/workflows/ci.yml
+++ /dev/null
@@ -1,26 +0,0 @@
-name: CI
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-jobs:
-  host-check:
-    name: Host (Rust)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          components: rustfmt, clippy
-      - name: Format
-        run: cargo fmt --manifest-path host/Cargo.toml -- --check
-      - name: Clippy
-        run: cargo clippy --manifest-path host/Cargo.toml --all-targets -- -D warnings
-      - name: Test
-        run: cargo test --manifest-path host/Cargo.toml
diff --git a/README.md b/README.md
index af6380b..bfd16e7 100644
--- a/README.md
+++ b/README.md
@@ -23,58 +23,73 @@ Operating System
 | `Stdout` | `uses [Console]` | Standard output |
 | `Stdin` | `uses [Console]` | Standard input |
 | `File` | `uses [FileRead]` or `uses [FileWrite]` | File system operations |
-| `Dir` | `uses [FileRead]` | Directory listing |
+| `Dir` | `uses [FileRead]` or `uses [FileWrite]` | Directory listing and creation |
 | `Env` | `uses [Env]` | Environment variables |
 | `Cmd` | `uses [Spawn]` | Process execution |
 
 ## Quick Start
 
 ```spore
-// hello.sp
-uses [Console]
-
-fn main() -> Unit uses [Console] {
-    println("Hello from basic-cli!")
+/// A simple "Hello World" using the basic-cli platform.
+fn main() -> () uses [Console] {
+    println("Hello from Spore basic-cli!")
 }
 ```
 
 ```bash
-spore run hello.sp --platform basic-cli
+spore check examples/hello.sp
+spore build examples/hello.sp
+spore run examples/hello.sp
 ```
 
+This repository currently keeps `examples/` limited to files that PR CI validates today.
+It also intentionally keeps the current loose `.sp` file layout for now; the manifest/package-layout migration is deferred to a follow-up change.
+
 ## Project Structure
 
 ```
 basic-cli/
-├── platform/          # Spore API modules (.sp files)
+├── platform/          # Spore API modules (.sp files), checked and built in CI
 │   ├── Stdout.sp      # Standard output operations
 │   ├── Stdin.sp       # Standard input operations
 │   ├── File.sp        # File read/write operations
 │   ├── Dir.sp         # Directory operations
 │   ├── Env.sp         # Environment variable access
 │   ├── Cmd.sp         # Process execution
-│   └── main.sp        # Platform entry point
 ├── host/              # Rust host implementation
 │   ├── Cargo.toml
 │   └── src/
 │       └── lib.rs     # Foreign function implementations
-├── examples/          # Example Spore programs using this platform
-└── tests/             # Integration tests
+└── examples/          # Canonical examples that format/check/build in CI
 ```
 
+## Tutorial Contract
+
+- `examples/` is for truthful, CI-validated examples only.
+- `platform/` is the API surface for the platform modules themselves.
+- Only add `tests/` when the repo has real Spore-side regression coverage worth running with `spore test`.
+
+If you want to add a new tutorial/example, treat this as the bar:
+
+1. keep it self-contained;
+2. make sure it passes `spore format --check`, `spore check`, and `spore build`;
+3. only then promote it into `examples/` and mention it in this README.
+
 ## Design Philosophy
 
-Following Spore's [SEP-0005 (Effect System)](https://github.com/spore-lang/spore-evolution):
+Following Spore's [SEP-0003 (Effect Capability System)](https://github.com/spore-lang/spore-evolution/blob/main/seps/SEP-0003-effect-capability-system.md):
 
 - **Capability-gated**: Every I/O function declares its required capabilities via `uses [Cap]`
-- **Cost-annotated**: Platform functions carry `cost ≤ N` budgets where meaningful
-- **Error-typed**: Functions declare error sets via `! [ErrorType]`
+- **Cost-annotated**: Platform functions can carry `cost [c, a, i, p]` budgets where meaningful
+- **Error-typed**: Functions declare error sets via `! ErrorType`
 - **Pure by default**: The platform boundary is the only place side effects occur
 
 ## Status
 
 🚧 **Early development** — API is unstable and subject to change.
 
+At the moment, the validated example is `examples/hello.sp`. More ambitious host-backed demos such as environment/file workflows should stay out of `examples/` until the current platform import/runtime architecture supports them honestly.
+
 ## License
 
 MIT — see [LICENSE](LICENSE).
diff --git a/examples/env-reader.sp b/examples/env-reader.sp
deleted file mode 100644
index 63b1884..0000000
--- a/examples/env-reader.sp
+++ /dev/null
@@ -1,11 +0,0 @@
-/// Environment variable reader.
-///
-/// Demonstrates Env and Console capabilities.
-uses [Env, Console]
-
-fn main() -> Unit uses [Env, Console] {
-    match env_get("HOME") {
-        Some(home) => println("Home directory: " + home),
-        None => println("HOME not set"),
-    }
-}
diff --git a/examples/file-copy.sp b/examples/file-copy.sp
deleted file mode 100644
index 366ce3d..0000000
--- a/examples/file-copy.sp
+++ /dev/null
@@ -1,10 +0,0 @@
-/// File copy example — reads a file and writes it to another path.
-///
-/// Demonstrates FileRead and FileWrite capabilities.
-uses [FileRead, FileWrite, Console]
-
-fn main() -> Unit uses [FileRead, FileWrite, Console] ! [IoError] {
-    let content = file_read("input.txt")
-    file_write("output.txt", content)
-    println("File copied successfully!")
-}
diff --git a/examples/hello.sp b/examples/hello.sp
index e8a4d41..9cdabdc 100644
--- a/examples/hello.sp
+++ b/examples/hello.sp
@@ -1,8 +1,4 @@
 /// A simple "Hello World" using the basic-cli platform.
 ///
-/// Run with: spore run examples/hello.sp --platform basic-cli
-uses [Console]
-
-fn main() -> Unit uses [Console] {
-    println("Hello from Spore basic-cli!")
-}
+/// Run with: spore run examples/hello.sp
+fn main() -> () uses [Console] { println("Hello from Spore basic-cli!") }
diff --git a/platform/Cmd.sp b/platform/Cmd.sp
index cd1e351..1e9770f 100644
--- a/platform/Cmd.sp
+++ b/platform/Cmd.sp
@@ -4,11 +4,7 @@
 
 /// Run a command and capture its stdout as a string.
 /// Returns the full stdout output on success.
-foreign fn process_run(cmd: String, args: List[String]) -> String
-    uses [Spawn]
-    ! [ExecError]
+foreign fn process_run(cmd: String, args: List[String]) -> String ! ExecError uses [Spawn]
 
 /// Run a command and return its exit code.
-foreign fn process_run_status(cmd: String, args: List[String]) -> Int
-    uses [Spawn]
-    ! [ExecError]
+foreign fn process_run_status(cmd: String, args: List[String]) -> Int ! ExecError uses [Spawn]
diff --git a/platform/Dir.sp b/platform/Dir.sp
index cce3b33..e279873 100644
--- a/platform/Dir.sp
+++ b/platform/Dir.sp
@@ -1,11 +1,7 @@
 /// basic-cli platform — Directory operations
 
 /// List entries in a directory, returning their names.
-foreign fn dir_list(path: String) -> List[String]
-    uses [FileRead]
-    ! [IoError]
+foreign fn dir_list(path: String) -> List[String] ! IoError uses [FileRead]
 
 /// Create a directory (and any missing parents).
-foreign fn dir_mkdir(path: String) -> Unit
-    uses [FileWrite]
-    ! [IoError]
+foreign fn dir_mkdir(path: String) -> Unit ! IoError uses [FileWrite]
diff --git a/platform/Env.sp b/platform/Env.sp
index d964382..22a6bb2 100644
--- a/platform/Env.sp
+++ b/platform/Env.sp
@@ -1,9 +1,7 @@
 /// basic-cli platform — Environment variable access
 
 /// Get the value of an environment variable, or None if not set.
-foreign fn env_get(key: String) -> Option[String]
-    uses [Env]
+foreign fn env_get(key: String) -> Option[String] uses [Env]
 
 /// Set an environment variable.
-foreign fn env_set(key: String, value: String) -> Unit
-    uses [Env]
+foreign fn env_set(key: String, value: String) -> Unit uses [Env]
diff --git a/platform/File.sp b/platform/File.sp
index ac027d9..0d40000 100644
--- a/platform/File.sp
+++ b/platform/File.sp
@@ -3,20 +3,13 @@
 /// Provides capability-gated file read and write operations.
 
 /// Read the entire contents of a file as a string.
-foreign fn file_read(path: String) -> String
-    uses [FileRead]
-    ! [IoError]
+foreign fn file_read(path: String) -> String ! IoError uses [FileRead]
 
 /// Write content to a file, creating or overwriting it.
-foreign fn file_write(path: String, content: String) -> Unit
-    uses [FileWrite]
-    ! [IoError]
+foreign fn file_write(path: String, content: String) -> Unit ! IoError uses [FileWrite]
 
 /// Check whether a file or directory exists at the given path.
-foreign fn file_exists(path: String) -> Bool
-    uses [FileRead]
+foreign fn file_exists(path: String) -> Bool uses [FileRead]
 
 /// Get file metadata (size, modified time, etc.) as a string representation.
-foreign fn file_stat(path: String) -> String
-    uses [FileRead]
-    ! [IoError]
+foreign fn file_stat(path: String) -> String ! IoError uses [FileRead]
diff --git a/platform/Stdin.sp b/platform/Stdin.sp
index fd4aa7d..7e86f64 100644
--- a/platform/Stdin.sp
+++ b/platform/Stdin.sp
@@ -1,5 +1,4 @@
 /// basic-cli platform — Standard input operations
 
 /// Read a line from stdin (blocks until newline).
-foreign fn read_line() -> String
-    uses [Console]
+foreign fn read_line() -> String uses [Console]
diff --git a/platform/Stdout.sp b/platform/Stdout.sp
index 96ffe7d..3c1b05b 100644
--- a/platform/Stdout.sp
+++ b/platform/Stdout.sp
@@ -3,17 +3,13 @@
 /// Provides capability-gated access to stdout/stderr.
 
 /// Print a string to stdout without trailing newline.
-foreign fn print(s: String) -> Unit
-    uses [Console]
+foreign fn print(s: String) -> Unit uses [Console]
 
 /// Print a string to stdout with trailing newline.
-foreign fn println(s: String) -> Unit
-    uses [Console]
+foreign fn println(s: String) -> Unit uses [Console]
 
 /// Print a formatted string to stderr.
-foreign fn eprint(s: String) -> Unit
-    uses [Console]
+foreign fn eprint(s: String) -> Unit uses [Console]
 
 /// Print a formatted string to stderr with trailing newline.
-foreign fn eprintln(s: String) -> Unit
-    uses [Console]
+foreign fn eprintln(s: String) -> Unit uses [Console]
diff --git a/platform/main.sp b/platform/main.sp
deleted file mode 100644
index b74c5a7..0000000
--- a/platform/main.sp
+++ /dev/null
@@ -1,12 +0,0 @@
-/// basic-cli platform entry point
-///
-/// Re-exports all platform modules for convenient access.
-/// Usage: `uses basic-cli` in your Spore application.
-
-// Platform modules
-pub use Stdout.{print, println, eprint, eprintln}
-pub use Stdin.{read_line}
-pub use File.{file_read, file_write, file_exists, file_stat}
-pub use Dir.{dir_list, dir_mkdir}
-pub use Env.{env_get, env_set}
-pub use Cmd.{process_run, process_run_status}
diff --git a/prek.toml b/prek.toml
new file mode 100644
index 0000000..19c6d5f
--- /dev/null
+++ b/prek.toml
@@ -0,0 +1,58 @@
+[[repos]]
+repo = "https://github.com/pre-commit/pre-commit-hooks"
+rev = "v6.0.0"
+hooks = [
+  { id = "check-added-large-files" },
+  { id = "check-case-conflict" },
+  { id = "check-executables-have-shebangs" },
+  { id = "check-yaml" },
+  { id = "check-json" },
+  { id = "check-merge-conflict" },
+  { id = "destroyed-symlinks" },
+  { id = "end-of-file-fixer" },
+  { id = "mixed-line-ending" },
+  { id = "trailing-whitespace" },
+]
+
+[[repos]]
+repo = "https://github.com/tombi-toml/tombi-pre-commit"
+rev = "v0.7.27"
+hooks = [
+  { id = "tombi-format", exclude = "^Cargo\\.lock$" },
+  { id = "tombi-lint" },
+]
+
+[[repos]]
+repo = "https://github.com/crate-ci/typos"
+rev = "v1.33.1"
+hooks = [
+  { id = "typos", args = ["--force-exclude"] },
+]
+
+[[repos]]
+repo = "https://github.com/zrr1999/zendev"
+rev = "e2a5243899467d0df1cb1ab0ddcb18f3ef33d97b"
+hooks = [
+  { id = "zendev-commit-msg" },
+]
+
+[[repos]]
+repo = "local"
+hooks = [
+  {
+    id = "cargo-fmt",
+    name = "cargo-fmt",
+    entry = "cargo fmt --manifest-path host/Cargo.toml --",
+    language = "system",
+    types = ["rust"],
+    pass_filenames = false,
+  },
+  {
+    id = "cargo-clippy",
+    name = "cargo-clippy",
+    entry = "cargo clippy --manifest-path host/Cargo.toml --all-targets -- -D warnings",
+    language = "system",
+    types = ["rust"],
+    pass_filenames = false,
+  },
+]