Merge canon log contract & api validation (Plan A)

JSON Schema contract for canon log + origin seeds (single source of truth),
validator module, POC deserter origin + minimal world fixtures with
id-resolution, canon-log validation wired into all five role endpoints
(422 on invalid), and schemas bundled into the Docker image with a passing
runtime smoke test. Full suite 25 passing.

.dockerignore

@@ -0,0 +1,14 @@
+.git
+.claude
+client
+content
+docs/*
+!docs/schemas
+**/__pycache__
+**/*.py[cod]
+.venv
+venv
+**/.pytest_cache
+api/tests
+api/.env
+api/.env.*

api/.dockerignore

@@ -1,16 +0,0 @@
-# Keep the build context small and secrets out of the image.
-.env
-.env.*
-__pycache__/
-*.py[cod]
-.venv/
-venv/
-.pytest_cache/
-.mypy_cache/
-.ruff_cache/
-.coverage
-htmlcov/
-docs/
-README.md
-Dockerfile
-.dockerignore

api/Dockerfile

@@ -1,8 +1,7 @@
-# /api — FastAPI proxy (charter §4). Docker-based for parity across
-# dev / homelab VPS / fly.io.
+# /api — FastAPI proxy (charter §4). Build context is the repo root so the
+# canon log schemas (/docs/schemas) are bundled into the image.
 FROM python:3.12-slim
 
-# Faster, quieter Python in containers.
 ENV PYTHONUNBUFFERED=1 \
     PYTHONDONTWRITEBYTECODE=1 \
     PIP_NO_CACHE_DIR=1
@@ -10,11 +9,12 @@ ENV PYTHONUNBUFFERED=1 \
 WORKDIR /app
 
 # Install deps first so the layer caches when only app code changes.
-COPY requirements.txt .
+COPY api/requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
-# App code.
-COPY app ./app
+# App code + the schema contract (single source of truth in docs/schemas).
+COPY api/app ./app
+COPY docs/schemas ./schemas
 
 # Run as non-root.
 RUN useradd --create-home --uid 1000 appuser

api/app/canon_log.py

@@ -0,0 +1,49 @@
+"""Load the JSON Schema contracts and validate canon logs / origin seeds.
+
+Schemas are the single source of truth in /docs/schemas. This module is the
+api's half of the contract (charter §11): every canon log the client posts is
+validated here before it could ever reach a prompt.
+"""
+
+import json
+import os
+from functools import lru_cache
+from pathlib import Path
+
+from jsonschema import Draft202012Validator
+
+
+def _schema_dir() -> Path:
+    """Locate the schema directory.
+
+    Honours CANON_SCHEMA_DIR, else walks up from this file looking for
+    docs/schemas (local checkout) or schemas (bundled into the Docker image).
+    """
+    env = os.environ.get("CANON_SCHEMA_DIR")
+    if env:
+        return Path(env)
+    here = Path(__file__).resolve()
+    for parent in here.parents:
+        for candidate in (parent / "docs" / "schemas", parent / "schemas"):
+            if candidate.is_dir():
+                return candidate
+    raise RuntimeError("schema directory not found")
+
+
+@lru_cache(maxsize=None)
+def _validator(schema_name: str) -> Draft202012Validator:
+    with open(_schema_dir() / schema_name) as f:
+        return Draft202012Validator(json.load(f))
+
+
+def validation_errors(doc: dict, schema_name: str) -> list[str]:
+    validator = _validator(schema_name)
+    return [e.message for e in sorted(validator.iter_errors(doc), key=lambda e: list(e.path))]
+
+
+def validate_origin(doc: dict) -> list[str]:
+    return validation_errors(doc, "origin.schema.json")
+
+
+def validate_canon_log(doc: dict) -> list[str]:
+    return validation_errors(doc, "canon-log.schema.json")

api/app/content.py

@@ -0,0 +1,50 @@
+"""Load authored world content and cross-check origin references.
+
+Language-neutral content integrity: every id an origin references (start
+location, start quest, granted items, seeded npc dispositions) must resolve in
+world content. New-game construction (client-side, Plan B) relies on this
+holding; catching it here fails a broken origin at authoring time, not three
+scenes into play.
+"""
+
+import json
+from pathlib import Path
+
+
+def _load_ids(dir_path: Path) -> set[str]:
+    ids: set[str] = set()
+    for f in dir_path.glob("*.json"):
+        with open(f) as fh:
+            ids.add(json.load(fh)["id"])
+    return ids
+
+
+def load_world(content_root: Path) -> dict[str, set[str]]:
+    world = content_root / "world"
+    return {
+        "locations": _load_ids(world / "locations"),
+        "npcs": _load_ids(world / "npcs"),
+        "quests": _load_ids(world / "quests"),
+        "items": _load_ids(world / "items"),
+    }
+
+
+def load_origin(path: Path) -> dict:
+    with open(path) as f:
+        return json.load(f)
+
+
+def unresolved_refs(origin: dict, world: dict[str, set[str]]) -> list[str]:
+    missing: list[str] = []
+    if origin["start_location_id"] not in world["locations"]:
+        missing.append(f"location:{origin['start_location_id']}")
+    quest = origin.get("start_quest_id")
+    if quest is not None and quest not in world["quests"]:
+        missing.append(f"quest:{quest}")
+    for grant in origin["inventory_grants"]:
+        if grant["item_id"] not in world["items"]:
+            missing.append(f"item:{grant['item_id']}")
+    for npc_id in origin["disposition_overrides"]:
+        if npc_id not in world["npcs"]:
+            missing.append(f"npc:{npc_id}")
+    return missing

api/app/main.py

@@ -1,15 +1,31 @@
 """FastAPI proxy entrypoint — the guarding proxy of charter §4.
 
-Skeleton only: a health check plus the five role endpoints as stubs so the
-container runs and the client has something to point at. Real prompt routing,
-model selection, logging, and auth land later — all server-side (§4, §5).
+Skeleton: a health check plus the five role endpoints. Each role endpoint now
+validates the posted canon log against the contract (charter §11) before doing
+anything else — an invalid log is rejected with 422 and never reaches a prompt.
+Prompt routing, model selection, and logging land later.
 """
 
-from fastapi import FastAPI
+from fastapi import Depends, FastAPI, HTTPException
+from pydantic import BaseModel
+
+from .canon_log import validate_canon_log
 
 app = FastAPI(title="coc-rpg proxy", version="0.0.1")
 
 
+class TurnRequest(BaseModel):
+    canon_log: dict
+
+
+def valid_turn(req: TurnRequest) -> TurnRequest:
+    """Shared dependency: reject any request whose canon log breaks the contract."""
+    errors = validate_canon_log(req.canon_log)
+    if errors:
+        raise HTTPException(status_code=422, detail={"canon_log_errors": errors})
+    return req
+
+
 @app.get("/health")
 def health() -> dict:
     """Liveness probe for compose / fly.io."""
@@ -18,30 +34,30 @@ def health() -> dict:
 
 # ── Role endpoints (charter §4) ──────────────────────────────────────────────
 # The client knows these paths and nothing about which model or prompt serves
-# them. Stubs for now; each will load its prompt from api/prompts/ and route to
-# the configured model.
+# them. Bodies are validated against the canon log contract; the AI half is a
+# stub until prompt routing lands.
 
 
 @app.post("/dm/narrate")
-def narrate() -> dict:
+def narrate(req: TurnRequest = Depends(valid_turn)) -> dict:
     return {"detail": "not implemented"}
 
 
 @app.post("/dm/adjudicate")
-def adjudicate() -> dict:
+def adjudicate(req: TurnRequest = Depends(valid_turn)) -> dict:
     return {"detail": "not implemented"}
 
 
 @app.post("/dm/improvise")
-def improvise() -> dict:
+def improvise(req: TurnRequest = Depends(valid_turn)) -> dict:
     return {"detail": "not implemented"}
 
 
 @app.post("/npc/speak")
-def npc_speak() -> dict:
+def npc_speak(req: TurnRequest = Depends(valid_turn)) -> dict:
     return {"detail": "not implemented"}
 
 
 @app.post("/party/banter")
-def banter() -> dict:
+def banter(req: TurnRequest = Depends(valid_turn)) -> dict:
     return {"detail": "not implemented"}

api/pytest.ini

@@ -0,0 +1,3 @@
+[pytest]
+pythonpath = .
+testpaths = tests

api/requirements-dev.txt

@@ -0,0 +1,2 @@
+# Dev/test deps. Installed on top of requirements.txt.
+pytest==8.3.2

api/requirements.txt

@@ -3,3 +3,4 @@ fastapi==0.139.0
 uvicorn[standard]==0.51.0
 httpx==0.28.1        # calling Ollama / Replicate
 pydantic==2.13.4     # request/response contracts
+jsonschema==4.23.0   # canon log / origin contract validation

api/tests/fixtures/canon_log_valid.json

@@ -0,0 +1,29 @@
+{
+  "schema_version": 1,
+  "player": {
+    "name": "Aldric",
+    "class_id": "sellsword",
+    "luck_descriptor": "Fortune spits on you"
+  },
+  "location": { "id": "greywater_docks", "name": "the Greywater docks" },
+  "party": [
+    { "id": "brannoc_thane", "name": "Brannoc Thane", "disposition": 40 },
+    { "id": "cadwyn_vell", "name": "Cadwyn Vell", "disposition": 15 }
+  ],
+  "recent_events": [
+    "Arrived at Greywater by barge before dawn",
+    "Brannoc recognised the harbourmaster and went quiet"
+  ],
+  "established_facts": [
+    "the eastern bridge out of Greywater is washed out",
+    "the harbourmaster is named Oda Fenn"
+  ],
+  "active_quests": [
+    { "id": "find_the_ledger", "name": "The Missing Ledger",
+      "status": "active", "objective": "Find who took Fenn's ledger" }
+  ],
+  "humiliations": [
+    { "id": "h_0001", "text": "vomited on a shrine step in front of a priest",
+      "weight": 7, "turn": 3 }
+  ]
+}

api/tests/test_canon_log_schema.py

@@ -0,0 +1,70 @@
+import json
+from pathlib import Path
+
+from app.canon_log import validate_canon_log
+
+FIXTURE = Path(__file__).parent / "fixtures" / "canon_log_valid.json"
+
+
+def _valid():
+    with open(FIXTURE) as f:
+        return json.load(f)
+
+
+def test_valid_canon_log_passes():
+    assert validate_canon_log(_valid()) == []
+
+
+def test_numeric_luck_is_rejected():
+    # Charter §7: the AI must never be able to calculate Luck. A stray numeric
+    # luck field must fail validation, not slip through.
+    doc = _valid()
+    doc["player"]["luck"] = 5
+    assert validate_canon_log(doc) != []
+
+
+def test_recent_events_over_five_is_rejected():
+    doc = _valid()
+    doc["recent_events"] = [f"event {i}" for i in range(6)]
+    assert validate_canon_log(doc) != []
+
+
+def test_disposition_out_of_range_is_rejected():
+    doc = _valid()
+    doc["party"][0]["disposition"] = 200
+    assert validate_canon_log(doc) != []
+
+
+def test_unknown_quest_status_is_rejected():
+    doc = _valid()
+    doc["active_quests"][0]["status"] = "abandoned"
+    assert validate_canon_log(doc) != []
+
+
+def test_humiliation_weight_bounds_enforced():
+    doc = _valid()
+    doc["humiliations"][0]["weight"] = 11
+    assert validate_canon_log(doc) != []
+
+
+def test_empty_optional_arrays_are_allowed():
+    doc = _valid()
+    doc["party"] = []
+    doc["recent_events"] = []
+    doc["established_facts"] = []
+    doc["active_quests"] = []
+    doc["humiliations"] = []
+    assert validate_canon_log(doc) == []
+
+
+def test_root_level_stray_field_is_rejected():
+    # §2/§7: stats/HP/inventory must never enter the log — additionalProperties:false at root.
+    doc = _valid()
+    doc["hp"] = 10
+    assert validate_canon_log(doc) != []
+
+
+def test_negative_turn_is_rejected():
+    doc = _valid()
+    doc["humiliations"][0]["turn"] = -1
+    assert validate_canon_log(doc) != []

api/tests/test_content_resolution.py

@@ -0,0 +1,47 @@
+import copy
+import json
+from pathlib import Path
+
+from app.canon_log import validate_origin
+from app.content import load_world, load_origin, unresolved_refs
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+CONTENT_ROOT = REPO_ROOT / "content"
+DESERTER = CONTENT_ROOT / "origins" / "deserter.json"
+
+
+def test_deserter_origin_matches_schema():
+    assert validate_origin(load_origin(DESERTER)) == []
+
+
+def test_deserter_ids_all_resolve():
+    world = load_world(CONTENT_ROOT)
+    assert unresolved_refs(load_origin(DESERTER), world) == []
+
+
+def test_broken_location_ref_is_detected():
+    world = load_world(CONTENT_ROOT)
+    origin = copy.deepcopy(load_origin(DESERTER))
+    origin["start_location_id"] = "nowhere"
+    assert "location:nowhere" in unresolved_refs(origin, world)
+
+
+def test_broken_item_ref_is_detected():
+    world = load_world(CONTENT_ROOT)
+    origin = copy.deepcopy(load_origin(DESERTER))
+    origin["inventory_grants"].append({"item_id": "ghost_blade", "qty": 1})
+    assert "item:ghost_blade" in unresolved_refs(origin, world)
+
+
+def test_null_quest_ref_resolves():
+    world = load_world(CONTENT_ROOT)
+    origin = copy.deepcopy(load_origin(DESERTER))
+    origin["start_quest_id"] = None
+    assert unresolved_refs(origin, world) == []
+
+
+def test_broken_disposition_npc_ref_is_detected():
+    world = load_world(CONTENT_ROOT)
+    origin = copy.deepcopy(load_origin(DESERTER))
+    origin["disposition_overrides"]["ghost_npc"] = 10
+    assert "npc:ghost_npc" in unresolved_refs(origin, world)

api/tests/test_endpoints.py

@@ -0,0 +1,38 @@
+import json
+from pathlib import Path
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+client = TestClient(app)
+VALID_LOG = json.load(open(Path(__file__).parent / "fixtures" / "canon_log_valid.json"))
+
+ROLE_ENDPOINTS = [
+    "/dm/narrate", "/dm/adjudicate", "/dm/improvise",
+    "/npc/speak", "/party/banter",
+]
+
+
+def test_health_ok():
+    assert client.get("/health").json() == {"status": "ok"}
+
+
+def test_every_role_endpoint_accepts_a_valid_canon_log():
+    for path in ROLE_ENDPOINTS:
+        r = client.post(path, json={"canon_log": VALID_LOG})
+        assert r.status_code == 200, f"{path} rejected a valid log: {r.text}"
+
+
+def test_every_role_endpoint_rejects_an_invalid_canon_log():
+    bad = json.loads(json.dumps(VALID_LOG))
+    bad["player"]["luck"] = 5  # §7 leak
+    for path in ROLE_ENDPOINTS:
+        r = client.post(path, json={"canon_log": bad})
+        assert r.status_code == 422, f"{path} accepted an invalid log"
+        assert "canon_log_errors" in r.json()["detail"]
+
+
+def test_missing_canon_log_is_a_422():
+    r = client.post("/dm/narrate", json={})
+    assert r.status_code == 422

api/tests/test_origin_schema.py

@@ -0,0 +1,54 @@
+import copy
+
+from app.canon_log import validate_origin
+
+VALID_ORIGIN = {
+    "schema_version": 1,
+    "id": "deserter",
+    "display_name": "The Deserter",
+    "description": "You walked away from a company that doesn't allow walking away.",
+    "start_location_id": "greywater_docks",
+    "situation": ["Arrived at Greywater by barge before dawn, hood up"],
+    "opening_facts": ["the player deserted the Iron Kettle mercenary company"],
+    "disposition_overrides": {"brannoc_thane": 40, "cadwyn_vell": 15},
+    "inventory_grants": [{"item_id": "worn_shortsword", "qty": 1}],
+    "start_quest_id": "find_the_ledger",
+    "build_constraints": {
+        "allowed_classes": ["sellsword", "assassin", "priest"],
+        "luck_modifier": 0,
+    },
+}
+
+
+def test_valid_origin_passes():
+    assert validate_origin(VALID_ORIGIN) == []
+
+
+def test_null_start_quest_is_allowed():
+    doc = copy.deepcopy(VALID_ORIGIN)
+    doc["start_quest_id"] = None
+    assert validate_origin(doc) == []
+
+
+def test_unknown_class_is_rejected():
+    doc = copy.deepcopy(VALID_ORIGIN)
+    doc["build_constraints"]["allowed_classes"] = ["bard"]
+    assert validate_origin(doc) != []
+
+
+def test_missing_required_field_is_rejected():
+    doc = copy.deepcopy(VALID_ORIGIN)
+    del doc["start_location_id"]
+    assert validate_origin(doc) != []
+
+
+def test_extra_field_is_rejected():
+    doc = copy.deepcopy(VALID_ORIGIN)
+    doc["surprise"] = True
+    assert validate_origin(doc) != []
+
+
+def test_disposition_override_key_must_match_id_pattern():
+    doc = copy.deepcopy(VALID_ORIGIN)
+    doc["disposition_overrides"] = {"Brannoc Thane": 40}
+    assert validate_origin(doc) != []

content/origins/deserter.json

@@ -0,0 +1,25 @@
+{
+  "schema_version": 1,
+  "id": "deserter",
+  "display_name": "The Deserter",
+  "description": "You walked away from a company that doesn't allow walking away. Greywater was just far enough. You hoped.",
+  "start_location_id": "greywater_docks",
+  "situation": [
+    "Arrived at Greywater by barge before dawn, hood up",
+    "Down to your last coin and owed a favour you can't repay"
+  ],
+  "opening_facts": [
+    "the player deserted the Iron Kettle mercenary company",
+    "a bounty notice for the player circulates in the northern towns"
+  ],
+  "disposition_overrides": { "brannoc_thane": 40, "cadwyn_vell": 15 },
+  "inventory_grants": [
+    { "item_id": "worn_shortsword", "qty": 1 },
+    { "item_id": "coin", "qty": 3 }
+  ],
+  "start_quest_id": "find_the_ledger",
+  "build_constraints": {
+    "allowed_classes": ["sellsword", "assassin", "priest"],
+    "luck_modifier": 0
+  }
+}

content/world/items/coin.json

@@ -0,0 +1 @@
+{ "id": "coin", "name": "coin", "slot": "currency" }

content/world/items/worn_shortsword.json

@@ -0,0 +1 @@
+{ "id": "worn_shortsword", "name": "a worn shortsword", "slot": "weapon" }

content/world/locations/greywater_docks.json

@@ -0,0 +1,2 @@
+{ "id": "greywater_docks", "name": "the Greywater docks",
+  "description": "A rot-black wharf where the river meets the sea trade." }

content/world/npcs/brannoc_thane.json

@@ -0,0 +1,3 @@
+{ "id": "brannoc_thane", "name": "Brannoc Thane", "role": "companion",
+  "persona": "Dry, warm, economical. Twenty years past his prime and at peace with it.",
+  "knowledge": [] }

content/world/npcs/cadwyn_vell.json

@@ -0,0 +1,3 @@
+{ "id": "cadwyn_vell", "name": "Cadwyn Vell", "role": "companion",
+  "persona": "Florid when performing, clipped when scared. A fine musician and a finer liar.",
+  "knowledge": [] }

content/world/quests/find_the_ledger.json

@@ -0,0 +1,2 @@
+{ "id": "find_the_ledger", "name": "The Missing Ledger",
+  "objective": "Find who took Fenn's ledger" }

docker-compose.yml

@@ -1,17 +1,22 @@
 # Local dev — run the proxy in Docker with live reload.
 #   docker compose up --build
+# Build context is the repo root so docs/schemas is available to the image.
 # Ollama runs on the homelab (charter §4), not here — point OLLAMA_BASE_URL at it.
 services:
   api:
-    build: ./api
+    build:
+      context: .
+      dockerfile: api/Dockerfile
     ports:
       - "8000:8000"
     env_file:
-      - ./api/.env
+      - path: ./api/.env
+        required: false
     environment:
       PORT: 8000
-    # Mount source + reload so edits are live without a rebuild.
+    # Mount source + schemas so edits are live without a rebuild.
     volumes:
       - ./api/app:/app/app:ro
+      - ./docs/schemas:/app/schemas:ro
     command: >
       uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload

docs/schemas/canon-log.schema.json

@@ -0,0 +1,83 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://coc-rpg/schemas/canon-log.schema.json",
+  "title": "Canon Log",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schema_version", "player", "location", "party",
+    "recent_events", "established_facts", "active_quests", "humiliations"
+  ],
+  "properties": {
+    "schema_version": { "type": "integer", "const": 1 },
+    "player": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": ["name", "class_id", "luck_descriptor"],
+      "properties": {
+        "name": { "type": "string", "minLength": 1 },
+        "class_id": { "enum": ["sellsword", "assassin", "priest"] },
+        "luck_descriptor": { "type": "string", "minLength": 1 }
+      }
+    },
+    "location": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": ["id", "name"],
+      "properties": {
+        "id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+        "name": { "type": "string", "minLength": 1 }
+      }
+    },
+    "party": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": ["id", "name", "disposition"],
+        "properties": {
+          "id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+          "name": { "type": "string", "minLength": 1 },
+          "disposition": { "type": "integer", "minimum": -100, "maximum": 100 }
+        }
+      }
+    },
+    "recent_events": {
+      "type": "array",
+      "maxItems": 5,
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "established_facts": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "active_quests": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": ["id", "name", "status", "objective"],
+        "properties": {
+          "id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+          "name": { "type": "string", "minLength": 1 },
+          "status": { "enum": ["active", "complete", "failed"] },
+          "objective": { "type": "string", "minLength": 1 }
+        }
+      }
+    },
+    "humiliations": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": ["id", "text", "weight", "turn"],
+        "properties": {
+          "id": { "type": "string", "minLength": 1, "pattern": "^[a-z0-9_]+$" },
+          "text": { "type": "string", "minLength": 1 },
+          "weight": { "type": "integer", "minimum": 1, "maximum": 10 },
+          "turn": { "type": "integer", "minimum": 0 }
+        }
+      }
+    }
+  }
+}

docs/schemas/origin.schema.json

@@ -0,0 +1,53 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://coc-rpg/schemas/origin.schema.json",
+  "title": "Origin Seed",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schema_version", "id", "display_name", "description",
+    "start_location_id", "situation", "opening_facts",
+    "disposition_overrides", "inventory_grants", "start_quest_id",
+    "build_constraints"
+  ],
+  "properties": {
+    "schema_version": { "type": "integer", "const": 1 },
+    "id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+    "display_name": { "type": "string", "minLength": 1 },
+    "description": { "type": "string", "minLength": 1 },
+    "start_location_id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+    "situation": { "type": "array", "items": { "type": "string", "minLength": 1 } },
+    "opening_facts": { "type": "array", "items": { "type": "string", "minLength": 1 } },
+    "disposition_overrides": {
+      "type": "object",
+      "propertyNames": { "pattern": "^[a-z0-9_]+$" },
+      "additionalProperties": { "type": "integer", "minimum": -100, "maximum": 100 }
+    },
+    "inventory_grants": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": ["item_id", "qty"],
+        "properties": {
+          "item_id": { "type": "string", "pattern": "^[a-z0-9_]+$" },
+          "qty": { "type": "integer", "minimum": 1 }
+        }
+      }
+    },
+    "start_quest_id": { "type": ["string", "null"], "pattern": "^[a-z0-9_]+$" },
+    "build_constraints": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": ["allowed_classes", "luck_modifier"],
+      "properties": {
+        "allowed_classes": {
+          "type": "array",
+          "minItems": 1,
+          "items": { "enum": ["sellsword", "assassin", "priest"] }
+        },
+        "luck_modifier": { "type": "integer" }
+      }
+    }
+  }
+}