fix: The issue was that response.content returns SDK objects that can't be properly serialized when passed back to the API.

agents/s01_agent_loop.py

@@ -28,6 +28,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -70,8 +71,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        # Append assistant turn
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         # If the model didn't call a tool, we're done
         if response.stop_reason != "tool_use":
             return

agents/s02_tool_use.py

@@ -24,6 +24,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -116,7 +117,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s03_todo_write.py

@@ -32,6 +32,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -168,7 +169,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s04_subagent.py

@@ -28,6 +28,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -119,7 +120,7 @@ def run_subagent(prompt: str) -> str:
             model=MODEL, system=SUBAGENT_SYSTEM, messages=sub_messages,
             tools=CHILD_TOOLS, max_tokens=8000,
         )
-        sub_messages.append({"role": "assistant", "content": response.content})
+        sub_messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             break
         results = []
@@ -146,7 +147,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=PARENT_TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s05_skill_loading.py

@@ -41,6 +41,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -190,7 +191,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s06_context_compact.py

@@ -41,6 +41,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -203,7 +204,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s07_task_system.py

@@ -28,6 +28,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -212,7 +213,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s08_background_tasks.py

@@ -32,6 +32,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -198,7 +199,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s09_agent_teams.py

@@ -51,6 +51,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 if os.getenv("ANTHROPIC_BASE_URL"):
@@ -360,7 +361,7 @@ def agent_loop(messages: list):
             tools=TOOLS,
             max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s10_team_protocols.py

@@ -56,6 +56,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 if os.getenv("ANTHROPIC_BASE_URL"):
@@ -441,7 +442,7 @@ def agent_loop(messages: list):
             tools=TOOLS,
             max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s11_autonomous_agents.py

@@ -44,6 +44,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 if os.getenv("ANTHROPIC_BASE_URL"):
@@ -525,7 +526,7 @@ def agent_loop(messages: list):
             tools=TOOLS,
             max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         results = []

agents/s12_worktree_task_isolation.py

@@ -38,6 +38,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 
@@ -734,7 +735,7 @@ def agent_loop(messages: list):
             tools=TOOLS,
             max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
 

agents/s_full.py

@@ -47,6 +47,7 @@
 
 from anthropic import Anthropic
 from dotenv import load_dotenv
+from utils import content_to_dicts
 
 load_dotenv(override=True)
 if os.getenv("ANTHROPIC_BASE_URL"):
@@ -180,7 +181,7 @@ def run_subagent(prompt: str, agent_type: str = "Explore") -> str:
     resp = None
     for _ in range(30):
         resp = client.messages.create(model=MODEL, messages=sub_msgs, tools=sub_tools, max_tokens=8000)
-        sub_msgs.append({"role": "assistant", "content": resp.content})
+        sub_msgs.append({"role": "assistant", "content": content_to_dicts(resp.content)})
         if resp.stop_reason != "tool_use":
             break
         results = []
@@ -468,7 +469,7 @@ def _loop(self, name: str, role: str, prompt: str):
                 except Exception:
                     self._set_status(name, "shutdown")
                     return
-                messages.append({"role": "assistant", "content": response.content})
+                messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
                 if response.stop_reason != "tool_use":
                     break
                 results = []
@@ -675,7 +676,7 @@ def agent_loop(messages: list):
             model=MODEL, system=SYSTEM, messages=messages,
             tools=TOOLS, max_tokens=8000,
         )
-        messages.append({"role": "assistant", "content": response.content})
+        messages.append({"role": "assistant", "content": content_to_dicts(response.content)})
         if response.stop_reason != "tool_use":
             return
         # Tool execution

agents/utils.py

@@ -0,0 +1,6 @@
+"""Shared utilities for all agent files."""
+
+
+def content_to_dicts(content) -> list:
+    """Convert Anthropic SDK response content blocks to serializable dicts."""
+    return [{"type": b.type, **b.model_dump(exclude={"type"})} for b in content]