chore(core): add function to coerce metadata (#557)

python/src/uagents/agent.py

@@ -42,16 +42,9 @@
 from uagents.envelope import EnvelopeHistory, EnvelopeHistoryEntry
 from uagents.mailbox import MailboxClient
 from uagents.models import ErrorMessage, Model
-from uagents.network import (
-    InsufficientFundsError,
-    get_almanac_contract,
-    get_ledger,
-)
+from uagents.network import InsufficientFundsError, get_almanac_contract, get_ledger
 from uagents.protocol import Protocol
-from uagents.registration import (
-    AgentRegistrationPolicy,
-    DefaultRegistrationPolicy,
-)
+from uagents.registration import AgentRegistrationPolicy, DefaultRegistrationPolicy
 from uagents.resolver import GlobalResolver, Resolver
 from uagents.storage import KeyValueStore, get_or_create_private_keys
 from uagents.types import (

python/src/uagents/registration.py

@@ -3,7 +3,7 @@
 import json
 import logging
 from abc import ABC, abstractmethod
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Union
 
 import aiohttp
 from cosmpy.aerial.client import LedgerClient
@@ -30,6 +30,25 @@ def generate_backoff_time(retry: int) -> float:
     return (2 ** (min(retry, 11) + 6)) / 1000
 
 
+def coerce_metadata_to_str(
+    metadata: Optional[Dict[str, Any]],
+) -> Optional[Dict[str, Union[str, Dict[str, str]]]]:
+    """
+    Step through the metadata and convert any non-string values to strings.
+    """
+    if metadata is None:
+        return None
+    out = {}
+    for key, val in metadata.items():
+        if isinstance(val, dict):
+            out[key] = {
+                k: v if isinstance(v, str) else json.dumps(v) for k, v in val.items()
+            }
+        else:
+            out[key] = val if isinstance(val, str) else json.dumps(val)
+    return out
+
+
 class AgentRegistrationPolicy(ABC):
     @abstractmethod
     # pylint: disable=unnecessary-pass
@@ -47,7 +66,7 @@ class AgentRegistrationAttestation(BaseModel):
     agent_address: str
     protocols: List[str]
     endpoints: List[AgentEndpoint]
-    metadata: Optional[Dict[str, Any]] = None
+    metadata: Optional[Dict[str, Union[str, Dict[str, str]]]] = None
     signature: Optional[str] = None
 
     def sign(self, identity: Identity):
@@ -112,7 +131,7 @@ async def register(
             agent_address=agent_address,
             protocols=protocols,
             endpoints=endpoints,
-            metadata=clean_metadata,
+            metadata=coerce_metadata_to_str(clean_metadata),
         )
 
         # sign the attestation

python/tests/test_registration.py

@@ -8,6 +8,7 @@
 from uagents.registration import (
     AgentRegistrationAttestation,
     AlmanacApiRegistrationPolicy,
+    coerce_metadata_to_str,
 )
 from uagents.types import AgentEndpoint
 
@@ -44,7 +45,9 @@ def test_attestation_signature_with_metadata():
         agent_address=identity.address,
         protocols=TEST_PROTOCOLS,
         endpoints=TEST_ENDPOINTS,
-        metadata={"foo": "bar", "baz": 3.17, "qux": {"a": "b", "c": 4, "d": 5.6}},
+        metadata=coerce_metadata_to_str(
+            {"foo": "bar", "baz": 3.17, "qux": {"a": "b", "c": 4, "d": 5.6}}
+        ),
     )
 
     # sign the attestation with the identity