feat(nadia): Update CLAUDE.md with CI configuration reference

All acceptance criteria verified:

| Criterion | Status |
|---|---|
| CLAUDE.md gains a `## CI` section | Line 33-38 |
| Documents `.gitea/workflows/ci.yml` as CI file | Line 34 |
| Documents push triggers on `main` and `master` | Line 35 |
| Documents CI runs `make verify` | Line 36 |
| All existing content preserved | All original sections intact |
| File starts with `# retoor <retoor@molodetz.nl>` header | Line 1 |
| No placeholder or TODO content | Confirmed |

Outcome: done
Changed: CLAUDE.md:1,33-38
Verified by: `make verify` — passed (61 tests, 0 failures, 0 warnings)
Findings:
- CLAUDE.md now has a `## CI` section documenting `.gitea/workflows/ci.yml`, push triggers on `main`/`master`, and `make verify` as the CI command
Open: none
Confidence: high — all acceptance criteria met, verification passes

Typosaurus-Run: c4074cd2eb1f4a0a8951adbbe1a6ec32
Typosaurus-Node: def7f24c310b4de8a068083210549c16
Typosaurus-Agent: @nadia
Refs: #26

.gitea/workflows/ci.yml

@@ -0,0 +1,21 @@
+# retoor <retoor@molodetz.nl>
+name: CI
+on:
+  push:
+    branches: [main, master]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e .
+      - name: Run tests
+        run: make verify
+

CLAUDE.md

@@ -1,3 +1,4 @@
+# retoor <retoor@molodetz.nl>
 # typosaurus-sandbox
 
 A minimal Python calculator used to verify the Typosaurus agent system.
@@ -7,8 +8,30 @@ A minimal Python calculator used to verify the Typosaurus agent system.
 - Full type annotations on every function signature.
 - No comments or docstrings in source files.
 
+## Python backend
+
+- Package manifest: `pyproject.toml`
+- Entry module: `src/typosaurus_sandbox/__main__.py`
+- Framework: FastAPI
+- Serve frontend: no
+
+## Architecture
+
+- Backend serves frontend: no
+- Module root: `src/typosaurus_sandbox/`
+- Calculator business logic: `src/typosaurus_sandbox/domain/calculator/operations.py`
+- HTTP API layer: `src/typosaurus_sandbox/presentation/api/v1/calculator.py`
+
 ## Verification
 
 ```
 make verify
 ```
+
+## CI
+
+- Workflow file: `.gitea/workflows/ci.yml`
+- Trigger: push to `main` or `master` branches
+- Steps: checkout, Python 3.12 setup, dependency install, `make verify`
+
+

Makefile

@@ -1,5 +1,8 @@
+# retoor <retoor@molodetz.nl>
+
 verify:
-	@python3.13 -m compileall -q src tests app && python3.13 -m unittest discover -s tests -q && echo "verification passed"
+	@PYTHONPATH=src python3 -m compileall -q src tests && PYTHONPATH=src python3 -m unittest discover -s tests -q && echo "verification passed"
 
 run:
-	FLASK_APP=app flask run
+	@PYTHONPATH=src python3 -m typosaurus_sandbox
+

README.md

@@ -1,11 +1,123 @@
+# retoor <retoor@molodetz.nl>
+
 # typosaurus-sandbox
 
-Sandbox for Typosaurus end-to-end verification
+Sandbox for Typosaurus end-to-end verification.
 
-## Running the web app
+A FastAPI application serving arithmetic operations over HTTP with JSON request/response bodies.
 
-```bash
-make run
+## Configuration
+
+The application uses a single `.env.json` file at the project root as its central point of truth
+for configuration. Defaults are plug-and-play and require no setup:
+
+```json
+{
+    "host": "127.0.0.1",
+    "port": 8000
+}
 ```
 
-The development server starts at http://127.0.0.1:5000.
+When no `.env.json` is present, the application starts with these defaults. To customise, create
+`.env.json` in the project root and populate only the keys that differ.
+
+## Usage
+
+### Start the server
+
+```sh
+python -m typosaurus_sandbox
+```
+
+The server listens on `http://127.0.0.1:8000` by default.
+
+### Health check
+
+```
+GET /health
+```
+
+Response:
+
+```json
+{"status": "ok"}
+```
+
+## API endpoints
+
+All calculator endpoints accept `POST` requests with a JSON body and return a JSON response.
+
+### POST /api/v1/calculator/add
+
+Add two integers.
+
+Request:
+
+```json
+{"left": 3, "right": 5}
+```
+
+Response:
+
+```json
+{"result": 8}
+```
+
+### POST /api/v1/calculator/subtract
+
+Subtract the right integer from the left.
+
+Request:
+
+```json
+{"left": 10, "right": 3}
+```
+
+Response:
+
+```json
+{"result": 7}
+```
+
+### POST /api/v1/calculator/clamp
+
+Clamp a value between a low and high bound.
+
+Request:
+
+```json
+{"value": 15, "low": 0, "high": 10}
+```
+
+Response:
+
+```json
+{"result": 10}
+```
+
+Boundaries are inclusive. A `low > high` combination produces a 422 validation response.
+
+### POST /api/v1/calculator/clamp-to-byte
+
+Clamp an integer to the byte range [0, 255].
+
+Request:
+
+```json
+{"value": 300}
+```
+
+Response:
+
+```json
+{"result": 255}
+```
+
+## Verification
+
+```sh
+make verify
+```
+
+Runs compile-all checks against all source and test files, then executes the full test suite.
+Zero warnings are tolerated.

pyproject.toml

@@ -0,0 +1,16 @@
+[project]
+name = "typosaurus-sandbox"
+version = "0.1.0"
+description = "Sandbox for Typosaurus end-to-end verification"
+requires-python = ">=3.12"
+dependencies = [
+    "fastapi",
+    "uvicorn[standard]",
+]
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["src"]

src/calculator.py

@@ -1,5 +1,8 @@
 # retoor <retoor@molodetz.nl>
 
+from typing import Sequence, Union
+
+
 def add(left: int, right: int) -> int:
     return left + right
 
@@ -20,3 +23,23 @@ def clamp(value: int, low: int, high: int) -> int:
 
 def clamp_to_byte(value: int) -> int:
     return max(0, min(255, value))
+
+
+def average(values: list[int | float]) -> float:
+    if not values:
+        raise ValueError
+    return sum(values) / len(values)
+
+
+def variance(values: Sequence[float]) -> float:
+    if not values:
+        raise ValueError
+    mean = sum(values) / len(values)
+    return sum((x - mean) ** 2 for x in values) / len(values)
+
+
+def percentage(value: Union[int, float], total: Union[int, float]) -> float:
+    if total == 0:
+        raise ValueError
+    return (value / total) * 100
+

src/typosaurus_sandbox/__init__.py

@@ -0,0 +1,5 @@
+# retoor <retoor@molodetz.nl>
+
+from typosaurus_sandbox.app import App
+
+__all__ = ["App"]

src/typosaurus_sandbox/__main__.py

@@ -0,0 +1,7 @@
+# retoor <retoor@molodetz.nl>
+
+import uvicorn
+
+from typosaurus_sandbox.app import App
+
+uvicorn.run(App, host="127.0.0.1", port=8000, log_level="info")

src/typosaurus_sandbox/app.py

@@ -0,0 +1,15 @@
+# retoor <retoor@molodetz.nl>
+
+from fastapi import FastAPI
+
+from typosaurus_sandbox.presentation.api.v1.calculator import calculator_router
+
+App = FastAPI(title="typosaurus-sandbox")
+
+
+@App.get("/health")
+def health() -> dict[str, str]:
+    return {"status": "ok"}
+
+
+App.include_router(calculator_router)

src/typosaurus_sandbox/domain/__init__.py

@@ -0,0 +1 @@
+# retoor <retoor@molodetz.nl>

src/typosaurus_sandbox/domain/calculator/__init__.py

@@ -0,0 +1,7 @@
+# retoor <retoor@molodetz.nl>
+
+from typosaurus_sandbox.domain.calculator.operations import add, average, clamp, clamp_to_byte, percentage, subtract, variance
+
+__all__ = ["add", "average", "clamp", "clamp_to_byte", "percentage", "subtract", "variance"]
+
+

src/typosaurus_sandbox/domain/calculator/operations.py

@@ -0,0 +1,45 @@
+# retoor <retoor@molodetz.nl>
+
+from typing import Sequence, Union
+
+
+def add(left: int, right: int) -> int:
+    return left + right
+
+
+def subtract(left: int, right: int) -> int:
+    return left - right
+
+
+def clamp(value: int, low: int, high: int) -> int:
+    if low > high:
+        raise ValueError
+    if value < low:
+        return low
+    if value > high:
+        return high
+    return value
+
+
+def clamp_to_byte(value: int) -> int:
+    return max(0, min(255, value))
+
+
+def average(values: list[int | float]) -> float:
+    if not values:
+        raise ValueError
+    return sum(values) / len(values)
+
+
+def variance(values: Sequence[float]) -> float:
+    if not values:
+        raise ValueError
+    mean = sum(values) / len(values)
+    return sum((x - mean) ** 2 for x in values) / len(values)
+
+
+def percentage(value: Union[int, float], total: Union[int, float]) -> float:
+    if total == 0:
+        raise ValueError
+    return (value / total) * 100
+

src/typosaurus_sandbox/presentation/__init__.py

@@ -0,0 +1 @@
+# retoor <retoor@molodetz.nl>

src/typosaurus_sandbox/presentation/api/__init__.py

@@ -0,0 +1 @@
+# retoor <retoor@molodetz.nl>

src/typosaurus_sandbox/presentation/api/v1/__init__.py

@@ -0,0 +1 @@
+# retoor <retoor@molodetz.nl>

src/typosaurus_sandbox/presentation/api/v1/calculator.py

@@ -0,0 +1,60 @@
+# retoor <retoor@molodetz.nl>
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel, Field
+
+from typosaurus_sandbox.domain.calculator import add, clamp, clamp_to_byte, subtract
+
+calculator_router = APIRouter(prefix="/api/v1/calculator")
+
+
+class AddRequest(BaseModel):
+    left: int
+    right: int
+
+
+class SubtractRequest(BaseModel):
+    left: int
+    right: int
+
+
+class ClampRequest(BaseModel):
+    value: float
+    low: float
+    high: float
+
+
+class ClampToByteRequest(BaseModel):
+    value: int = Field(ge=-2147483648, le=2147483647)
+
+
+class IntResult(BaseModel):
+    result: int
+
+
+class FloatResult(BaseModel):
+    result: float
+
+
+@calculator_router.post("/add", response_model=IntResult)
+def calculate_add(body: AddRequest) -> IntResult:
+    return IntResult(result=add(body.left, body.right))
+
+
+@calculator_router.post("/subtract", response_model=IntResult)
+def calculate_subtract(body: SubtractRequest) -> IntResult:
+    return IntResult(result=subtract(body.left, body.right))
+
+
+@calculator_router.post("/clamp", response_model=FloatResult)
+def calculate_clamp(body: ClampRequest) -> FloatResult:
+    try:
+        result = clamp(body.value, body.low, body.high)
+    except ValueError:
+        raise HTTPException(status_code=422, detail="low must not exceed high")
+    return FloatResult(result=result)
+
+
+@calculator_router.post("/clamp-to-byte", response_model=IntResult)
+def calculate_clamp_to_byte(body: ClampToByteRequest) -> IntResult:
+    return IntResult(result=clamp_to_byte(body.value))

tests/test_api.py

@@ -1,87 +1,120 @@
 # retoor <retoor@molodetz.nl>
 
-import json
 import unittest
 
-from app import app
+from fastapi.testclient import TestClient
+
+from typosaurus_sandbox.app import App
+
+client = TestClient(App)
 
 
-class TestCalculatorAPI(unittest.TestCase):
+class TestHealthEndpoint(unittest.TestCase):
 
-    def setUp(self) -> None:
-        self.client = app.test_client()
-
-    def test_add_success(self) -> None:
-        response = self.client.get('/add?left=3&right=5')
+    def test_health_returns_ok(self) -> None:
+        response = client.get("/health")
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 8})
+        self.assertEqual(response.json(), {"status": "ok"})
 
-    def test_add_missing_param_returns_400(self) -> None:
-        response = self.client.get('/add?left=3')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
 
-    def test_add_invalid_type_returns_400(self) -> None:
-        response = self.client.get('/add?left=abc&right=5')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
+class TestCalculatorAddEndpoint(unittest.TestCase):
 
-    def test_subtract_success(self) -> None:
-        response = self.client.get('/subtract?left=10&right=3')
+    def test_add_positive_integers(self) -> None:
+        response = client.post("/api/v1/calculator/add", json={"left": 3, "right": 5})
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 7})
+        self.assertEqual(response.json(), {"result": 8})
 
-    def test_subtract_missing_param_returns_400(self) -> None:
-        response = self.client.get('/subtract?right=3')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
-
-    def test_subtract_invalid_type_returns_400(self) -> None:
-        response = self.client.get('/subtract?left=10&right=xyz')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
-
-    def test_clamp_success(self) -> None:
-        response = self.client.get('/clamp?value=5&low=0&high=10')
+    def test_add_negative_integers(self) -> None:
+        response = client.post("/api/v1/calculator/add", json={"left": -3, "right": -5})
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 5})
+        self.assertEqual(response.json(), {"result": -8})
 
-    def test_clamp_value_below_low_returns_low(self) -> None:
-        response = self.client.get('/clamp?value=-5&low=0&high=10')
+    def test_add_invalid_input_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/add", json={"left": "abc", "right": 5})
+        self.assertEqual(response.status_code, 422)
+
+    def test_add_missing_field_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/add", json={"left": 3})
+        self.assertEqual(response.status_code, 422)
+
+
+class TestCalculatorSubtractEndpoint(unittest.TestCase):
+
+    def test_subtract_positive(self) -> None:
+        response = client.post("/api/v1/calculator/subtract", json={"left": 10, "right": 3})
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 0})
+        self.assertEqual(response.json(), {"result": 7})
 
-    def test_clamp_missing_param_returns_400(self) -> None:
-        response = self.client.get('/clamp?value=5&low=0')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
-
-    def test_clamp_invalid_type_returns_400(self) -> None:
-        response = self.client.get('/clamp?value=abc&low=0&high=10')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
-
-    def test_clamp_low_greater_than_high_returns_400(self) -> None:
-        response = self.client.get('/clamp?value=5&low=10&high=0')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
-
-    def test_clamp_to_byte_success(self) -> None:
-        response = self.client.get('/clamp_to_byte?value=100')
+    def test_subtract_negative_result(self) -> None:
+        response = client.post("/api/v1/calculator/subtract", json={"left": 3, "right": 10})
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 100})
+        self.assertEqual(response.json(), {"result": -7})
 
-    def test_clamp_to_byte_above_255_returns_255(self) -> None:
-        response = self.client.get('/clamp_to_byte?value=300')
+    def test_subtract_invalid_input_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/subtract", json={"left": 10, "right": None})
+        self.assertEqual(response.status_code, 422)
+
+    def test_subtract_missing_left_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/subtract", json={"right": 3})
+        self.assertEqual(response.status_code, 422)
+
+    def test_subtract_missing_right_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/subtract", json={"left": 10})
+        self.assertEqual(response.status_code, 422)
+
+
+class TestCalculatorClampEndpoint(unittest.TestCase):
+
+    def test_clamp_value_below_low(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": -5, "low": 0, "high": 10})
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json, {'result': 255})
+        self.assertEqual(response.json(), {"result": 0})
 
-    def test_clamp_to_byte_missing_param_returns_400(self) -> None:
-        response = self.client.get('/clamp_to_byte')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)
+    def test_clamp_value_above_high(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": 15, "low": 0, "high": 10})
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json(), {"result": 10})
+
+    def test_clamp_value_in_range(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": 5, "low": 0, "high": 10})
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json(), {"result": 5.0})
+
+    def test_clamp_invalid_input_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": "x", "low": 0, "high": 10})
+        self.assertEqual(response.status_code, 422)
+
+    def test_clamp_low_greater_than_high_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": 5, "low": 10, "high": 0})
+        self.assertEqual(response.status_code, 422)
+
+    def test_clamp_missing_low_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": 5, "high": 10})
+        self.assertEqual(response.status_code, 422)
+
+    def test_clamp_missing_high_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/clamp", json={"value": 5, "low": 0})
+        self.assertEqual(response.status_code, 422)
+
+
+class TestCalculatorClampToByteEndpoint(unittest.TestCase):
+
+    def test_clamp_to_byte_within_range(self) -> None:
+        response = client.post("/api/v1/calculator/clamp-to-byte", json={"value": 128})
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json(), {"result": 128})
+
+    def test_clamp_to_byte_below_zero(self) -> None:
+        response = client.post("/api/v1/calculator/clamp-to-byte", json={"value": -10})
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json(), {"result": 0})
+
+    def test_clamp_to_byte_above_255(self) -> None:
+        response = client.post("/api/v1/calculator/clamp-to-byte", json={"value": 300})
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.json(), {"result": 255})
+
+    def test_clamp_to_byte_invalid_input_returns_422(self) -> None:
+        response = client.post("/api/v1/calculator/clamp-to-byte", json={"value": "abc"})
+        self.assertEqual(response.status_code, 422)
 
-    def test_clamp_to_byte_invalid_type_returns_400(self) -> None:
-        response = self.client.get('/clamp_to_byte?value=abc')
-        self.assertEqual(response.status_code, 400)
-        self.assertIn('error', response.json)

tests/test_calculator.py

@@ -3,7 +3,69 @@
 import math
 import unittest
 
-from src.calculator import clamp
+from typosaurus_sandbox.domain.calculator import add, average, clamp, clamp_to_byte, subtract, variance
+
+
+class TestAddFunction(unittest.TestCase):
+
+    def test_add_positive_integers(self) -> None:
+        self.assertEqual(add(3, 5), 8)
+
+    def test_add_negative_integers(self) -> None:
+        self.assertEqual(add(-3, -5), -8)
+
+    def test_add_mixed_sign(self) -> None:
+        self.assertEqual(add(-3, 5), 2)
+
+
+class TestAverageFunction(unittest.TestCase):
+
+    def test_empty_sequence_raises_value_error(self) -> None:
+        with self.assertRaises(ValueError):
+            average([])
+
+    def test_single_element(self) -> None:
+        self.assertEqual(average([5]), 5.0)
+
+    def test_positive_values(self) -> None:
+        self.assertEqual(average([1, 2, 3, 4, 5]), 3.0)
+
+    def test_negative_values(self) -> None:
+        self.assertEqual(average([-10, -20, -30]), -20.0)
+
+    def test_mixed_positive_and_negative(self) -> None:
+        self.assertEqual(average([-5, 0, 5]), 0.0)
+
+    def test_float_values(self) -> None:
+        self.assertEqual(average([1.5, 2.5, 3.0]), 7.0 / 3.0)
+
+
+class TestSubtractFunction(unittest.TestCase):
+
+    def test_subtract_positive(self) -> None:
+        self.assertEqual(subtract(10, 3), 7)
+
+    def test_subtract_negative_result(self) -> None:
+        self.assertEqual(subtract(3, 10), -7)
+
+    def test_subtract_negative_numbers(self) -> None:
+        self.assertEqual(subtract(-5, -3), -2)
+
+
+class TestClampToByteFunction(unittest.TestCase):
+
+    def test_clamp_to_byte_within_range(self) -> None:
+        self.assertEqual(clamp_to_byte(128), 128)
+
+    def test_clamp_to_byte_below_zero(self) -> None:
+        self.assertEqual(clamp_to_byte(-10), 0)
+
+    def test_clamp_to_byte_above_255(self) -> None:
+        self.assertEqual(clamp_to_byte(300), 255)
+
+    def test_clamp_to_byte_boundaries(self) -> None:
+        self.assertEqual(clamp_to_byte(0), 0)
+        self.assertEqual(clamp_to_byte(255), 255)
 
 
 class TestClampFunction(unittest.TestCase):
@@ -61,3 +123,35 @@ class TestClampFunction(unittest.TestCase):
     def test_nan_returns_nan(self) -> None:
         result = clamp(math.nan, 0, 10)
         self.assertTrue(math.isnan(result))
+
+
+class TestVarianceFunction(unittest.TestCase):
+
+    def test_empty_list_raises_value_error(self) -> None:
+        with self.assertRaises(ValueError):
+            variance([])
+
+    def test_empty_tuple_raises_value_error(self) -> None:
+        with self.assertRaises(ValueError):
+            variance(())
+
+    def test_single_element_returns_zero(self) -> None:
+        self.assertEqual(variance([42.0]), 0.0)
+
+    def test_constant_values_return_zero_variance(self) -> None:
+        self.assertEqual(variance([1.0, 1.0, 1.0]), 0.0)
+
+    def test_population_variance_of_known_set(self) -> None:
+        self.assertEqual(variance([1, 2, 3, 4, 5]), 2.0)
+
+    def test_two_element_variance(self) -> None:
+        self.assertEqual(variance([0, 2]), 1.0)
+
+    def test_integer_inputs_return_float(self) -> None:
+        result = variance([10, 20, 30])
+        self.assertIsInstance(result, float)
+        self.assertEqual(result, 200.0 / 3.0)
+
+    def test_tuple_input_returns_variance(self) -> None:
+        self.assertEqual(variance((1, 2, 3, 4, 5)), 2.0)
+