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.

README.md

@@ -0,0 +1,173 @@
+# Dragonchain Python SDK
+
+A self-contained Python SDK for interacting with Dragonchain (Prime) nodes.
+
+## Installation
+
+```bash
+pip install prime-sdk-python
+```
+
+Or, from a local checkout:
+
+```bash
+pip install -e .
+```
+
+Requires Python 3.9+.
+
+## Usage
+
+```python
+from prime_sdk import DragonchainSDK, TransactionCreateRequest
+
+# Initialize the SDK
+client = DragonchainSDK(
+    "your-public-id",
+    "your-auth-key-id",
+    "your-auth-key",
+    "https://your-dragonchain-endpoint.com",
+)
+
+# Check system health (raises DragonchainAPIError if unhealthy)
+client.system.health()
+
+# Get system status
+status = client.system.status()
+print(f"Chain ID: {status.id}, Level: {status.level}")
+
+# Create a transaction
+resp = client.transaction.create(
+    TransactionCreateRequest(
+        txn_type="my-transaction-type",
+        payload='{"message": "Hello Dragonchain"}',
+        tag="example-tag",
+    )
+)
+print(f"Created transaction: {resp.transaction_id}")
+```
+
+## Transaction Modes
+
+`create` and `create_bulk` return **immediately** with the assigned transaction
+ID(s). They do **not** wait for block inclusion. Blocks are assembled
+asynchronously on a ~5-second cycle.
+
+### Fire and Forget
+
+Most use cases only need the transaction ID. No polling required.
+
+```python
+resp = client.transaction.create(
+    TransactionCreateRequest(
+        txn_type="my-transaction-type",
+        payload='{"message": "Hello Dragonchain"}',
+    )
+)
+print("Transaction ID:", resp.transaction_id)
+# Done — no need to wait for a block.
+```
+
+### Wait for Block
+
+If you need the block ID (e.g. for interchain verification or Daria), poll
+`get` until `header.block_id` is populated.
+
+```python
+import time
+
+resp = client.transaction.create(
+    TransactionCreateRequest(
+        txn_type="my-transaction-type",
+        payload='{"message": "Hello Dragonchain"}',
+    )
+)
+
+while True:
+    txn = client.transaction.get(resp.transaction_id)
+    if txn.header.block_id:
+        print("Block ID:", txn.header.block_id)
+        break
+    time.sleep(2)
+```
+
+## Loading credentials from a file
+
+The SDK can read chain credentials from a YAML file:
+
+```yaml
+default: my-public-id
+chains:
+  - name: my-chain
+    publicId: my-public-id
+    authKeyId: my-auth-key-id
+    authKey: my-auth-key
+    endpoint: https://chains.dragonchain.com
+```
+
+```python
+from prime_sdk import DragonchainSDK
+from prime_sdk.credentials import load_config
+
+cfg = load_config("~/.dragonchain/credentials.yaml")
+chain = cfg.get_default_chain()
+
+client = DragonchainSDK(
+    chain.public_id, chain.auth_key_id, chain.auth_key, chain.endpoint
+)
+```
+
+## Available Endpoints
+
+### System
+- `system.health()` — Check system health
+- `system.status()` — Get system status
+
+### Transaction
+- `transaction.create(req)` — Create a new transaction
+- `transaction.create_bulk(req)` — Create multiple transactions
+- `transaction.get(transaction_id)` — Get transaction by ID
+- `transaction.list()` — List all transactions
+
+### Transaction Type
+- `transaction_type.create(req)` — Create a new transaction type
+- `transaction_type.get(txn_type)` — Get transaction type by name
+- `transaction_type.list()` — List all transaction types
+- `transaction_type.delete(txn_type)` — Delete a transaction type
+
+### Smart Contract
+- `contract.create(req)` — Create a new smart contract
+- `contract.get(contract_id)` — Get smart contract by ID
+- `contract.list()` — List all smart contracts
+- `contract.update(contract_id, req)` — Update a smart contract
+- `contract.upload(contract_id, filepath)` — Upload smart contract code
+- `contract.delete(contract_id)` — Delete a smart contract
+
+### Block
+- `block.get(block_id)` — Get block by ID
+
+## Authentication
+
+The SDK uses HMAC-SHA256 authentication. You need to provide:
+- `public_id` — Your Dragonchain public ID
+- `auth_key_id` — Your authentication key ID
+- `auth_key` — Your authentication key
+- `base_url` — The base URL of your Dragonchain node (e.g. "https://chains.dragonchain.com")
+
+## Error handling
+
+Any non-2xx response raises `prime_sdk.DragonchainAPIError`, which exposes
+`.status_code` and `.body`:
+
+```python
+from prime_sdk import DragonchainAPIError
+
+try:
+    client.transaction.get("nonexistent-id")
+except DragonchainAPIError as e:
+    print(e.status_code, e.body)
+```
+
+## License
+
+Apache-2.0