Initial commit: Python SDK for Dragonchain (Prime)

Synchronous Python SDK modeled on prime-sdk-go. Provides DC1-HMAC-SHA256
auth, dataclass models, and resource clients for system, transaction,
transaction-type, smart-contract, and block endpoints, plus a YAML
credentials loader.

prime_sdk/transaction.py

@@ -0,0 +1,43 @@
+"""Transaction endpoints."""
+
+from .client import CONTENT_TYPE_JSON, Client
+from .models import (
+    ListTransactionsResponse,
+    Transaction,
+    TransactionBulkRequest,
+    TransactionBulkResponse,
+    TransactionCreateRequest,
+    TransactionCreateResponse,
+)
+
+
+class TransactionClient:
+    def __init__(self, client: Client):
+        self._client = client
+
+    def create(self, req: TransactionCreateRequest) -> TransactionCreateResponse:
+        """Submit a new transaction and return immediately with the assigned ID.
+
+        This does NOT wait for the transaction to be included in a block. Block
+        processing happens asynchronously on a ~5-second cycle. If you need the
+        block ID (e.g. for interchain verification), poll ``get`` until
+        ``header.block_id`` is populated.
+        """
+        return self._client.post(
+            "/api/v1/transaction", CONTENT_TYPE_JSON, req, TransactionCreateResponse
+        )
+
+    def create_bulk(self, req: TransactionBulkRequest) -> TransactionBulkResponse:
+        """Submit multiple transactions and return immediately with their IDs.
+
+        Like ``create``, this does not wait for block inclusion.
+        """
+        return self._client.post(
+            "/api/v1/transaction/bulk", CONTENT_TYPE_JSON, req, TransactionBulkResponse
+        )
+
+    def get(self, transaction_id: str) -> Transaction:
+        return self._client.get(f"/api/v1/transaction/{transaction_id}", Transaction)
+
+    def list(self) -> ListTransactionsResponse:
+        return self._client.get("/api/v1/transaction/", ListTransactionsResponse)