chore: initialize monorepo with project scaffolding, configs, and CI setup

packages/py/aitbc-crypto/src/receipt.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any, Dict
+
+import json
+from hashlib import sha256
+
+from pydantic import BaseModel
+
+
+class Receipt(BaseModel):
+    version: str
+    receipt_id: str
+    job_id: str
+    provider: str
+    client: str
+    units: float
+    unit_type: str
+    started_at: int
+    completed_at: int
+    price: float | None = None
+    model: str | None = None
+    prompt_hash: str | None = None
+    duration_ms: int | None = None
+    artifact_hash: str | None = None
+    coordinator_id: str | None = None
+    nonce: str | None = None
+    chain_id: int | None = None
+    metadata: Dict[str, Any] | None = None
+
+
+def canonical_json(receipt: Dict[str, Any]) -> str:
+    def remove_none(obj: Any) -> Any:
+        if isinstance(obj, dict):
+            return {k: remove_none(v) for k, v in obj.items() if v is not None}
+        if isinstance(obj, list):
+            return [remove_none(x) for x in obj if x is not None]
+        return obj
+
+    cleaned = remove_none(receipt)
+    return json.dumps(cleaned, separators=(",", ":"), sort_keys=True)
+
+
+def receipt_hash(receipt: Dict[str, Any]) -> bytes:
+    data = canonical_json(receipt).encode("utf-8")
+    return sha256(data).digest()