Release/v0.3.1

.gitignore

@@ -83,3 +83,4 @@ token.json
 
 video/
 video-new
+code-session.txt

README.md

@@ -7,7 +7,7 @@
 **See what your LangChain & LangGraph agents actually did.**
 Local-first observability — drop in one line, watch every run live in your browser.
 
-[![PyPI](https://img.shields.io/badge/pypi-v0.3.0-3775A9)](https://pypi.org/project/tracesage/)
+[![PyPI](https://img.shields.io/badge/pypi-v0.3.1-3775A9)](https://pypi.org/project/tracesage/)
 [![Python versions](https://img.shields.io/pypi/pyversions/tracesage)](https://pypi.org/project/tracesage/)
 [![License: MIT](https://img.shields.io/pypi/l/tracesage)](LICENSE)
 [![CI](https://github.com/kjgpta/tracesage/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/kjgpta/tracesage/actions/workflows/ci.yml)

docs/changelog.md

@@ -9,6 +9,38 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 _Nothing yet._
 
+## [0.3.1] — 2026-07-01
+
+A focused release that makes failed runs unmistakable in the UI and lets MCP tool
+errors surface as real failures.
+
+### Added
+- **`register_mcp_client(..., handle_tool_errors=False)`.** New keyword on the MCP
+  adapter (`tracesage.adapters.mcp`). By default (`True`) an MCP tool that errors
+  server-side returns the error as tool content — the model sees it and can recover,
+  matching langchain-mcp-adapters' behaviour. Pass `False` to make MCP tool errors
+  **raise** instead, so a broken tool call fails the run and shows up as a red error
+  node on the exact tool. Mirrors `ToolNode(handle_tool_errors=...)` for local tools.
+  The loader now binds tools to the server's connection config (not a transient
+  session) so each call opens its own session — fixing a `ClosedResourceError` when
+  errors propagate.
+
+### Changed
+- **Failed nodes render solid red.** In the topology / run-trace graph, a node that
+  errored is now filled solid `--error` red with a matching red glow — not just a red
+  outline. The error styling overrides the trace-mode success/step glows, so a broken
+  node reads unambiguously as red instead of blending toward orange.
+- **MCP server palette recoloured.** The per-server colour palette (`mcpServerColor`)
+  no longer includes red-family hues, so a healthy MCP server/tool is never confused
+  with a failed (red) node. Red is now reserved exclusively for errors.
+
+### Fixed
+- **`register_mcp_client` across langchain-mcp-adapters API variants.** The tool
+  loader falls back cleanly (`get_tools(server_name=...)` → connection config →
+  per-server session) and no longer leaks a closed session.
+- **Example `11_supervisor_research_team`** no longer raises `KeyError: 'next'` — the
+  supervisor's stop branch now always emits a routing key.
+
 ## [0.3.0] — 2026-06-23
 
 A major UI overhaul (topology vs. run-trace, step-through replay, readable

examples/showcase/11_supervisor_research_team/after.py

@@ -78,7 +78,9 @@ def build_graph() -> Runnable:
 
     async def supervise(state: TeamState) -> TeamState:
         if state["steps"] >= 4:
-            return {**state, "verdict": state.get("verdict") or "stopped"}
+            # Stop condition: always emit next="done" so pick() can route to END
+            # (a missing "next" key would KeyError in the conditional edge).
+            return {**state, "next": "done", "verdict": state.get("verdict") or "stopped"}
         route: Route = await router.ainvoke(
             f"Topic: {state['topic']}. Notes done={bool(state['notes'])}, "
             f"draft done={bool(state['draft'])}, checked={bool(state['verdict'])}. "
@@ -96,7 +98,8 @@ async def run_checker(state: TeamState) -> TeamState:
         return {**state, "verdict": await checker.ainvoke(state)}
 
     def pick(state: TeamState) -> str:
-        return END if state.get("next") == "done" else state["next"]
+        nxt = state.get("next", "done")
+        return END if nxt == "done" else nxt
 
     builder = StateGraph(TeamState)
     builder.add_node("supervisor", supervise)

examples/showcase/11_supervisor_research_team/before.py

@@ -70,7 +70,9 @@ def build_graph() -> Runnable:
 
     async def supervise(state: TeamState) -> TeamState:
         if state["steps"] >= 4:
-            return {**state, "verdict": state.get("verdict") or "stopped"}
+            # Stop condition: always emit next="done" so pick() can route to END
+            # (a missing "next" key would KeyError in the conditional edge).
+            return {**state, "next": "done", "verdict": state.get("verdict") or "stopped"}
         route: Route = await router.ainvoke(
             f"Topic: {state['topic']}. Notes done={bool(state['notes'])}, "
             f"draft done={bool(state['draft'])}, checked={bool(state['verdict'])}. "
@@ -88,7 +90,8 @@ async def run_checker(state: TeamState) -> TeamState:
         return {**state, "verdict": await checker.ainvoke(state)}
 
     def pick(state: TeamState) -> str:
-        return END if state.get("next") == "done" else state["next"]
+        nxt = state.get("next", "done")
+        return END if nxt == "done" else nxt
 
     builder = StateGraph(TeamState)
     builder.add_node("supervisor", supervise)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "tracesage"
-version = "0.3.0"
+version = "0.3.1"
 description = "Local-first observability for LangChain/LangGraph multi-agent systems"
 readme = "README.md"
 license = { text = "MIT" }