copilotkit__copilotkit/showcase/integrations/langgraph-python/qa/a2ui-recovery.md

QA: A2UI Error Recovery — LangGraph (Python)

Prerequisites

• Demo is deployed and accessible at /demos/a2ui-recovery on the dashboard host
• Agent backend is healthy; OPENAI_API_KEY is set; LANGGRAPH_DEPLOYMENT_URL points at the LangGraph deployment exposing the a2ui_recovery graph (registered as agent name a2ui-recovery — see src/app/api/copilotkit-a2ui-recovery/route.ts)
• Requires ag-ui-langgraph >= 0.0.41 (the get_a2ui_tools validate→retry recovery loop + a2ui_recovery_exhausted hard-fail envelope) and the @copilotkit A2UI renderer (the building/retrying/failed lifecycle rendering)
• Backend-owned wiring: the route sets injectA2UITool: false; the agent owns generate_a2ui via get_a2ui_tools({ recovery: { maxAttempts: 3 } }) (see src/agents/recovery_agent.py)
• Reuses the declarative-gen-ui catalog (catalogId: "declarative-gen-ui-catalog") and the Vantage Threads sales context — no new components

Test Steps

1. Basic Functionality

• Navigate to /demos/a2ui-recovery; verify the page renders within 3s and a single CopilotChat pane is centered (max-width ~896px, rounded-2xl, full-height)
• Verify the chat is wired to runtimeUrl="/api/copilotkit-a2ui-recovery" and agent="a2ui-recovery" (DevTools → Network: sending a message hits that endpoint, not /api/copilotkit)
• Verify both suggestion pills are visible with verbatim titles:
  • "Recover a bad render"
  • "Show an unrecoverable failure"

2. Healing path

• Click "Recover a bad render" ("Render my Q2 sales dashboard, recovering if the first attempt is malformed.")
• The inner render_a2ui returns free-form / sloppy A2UI args (components & data as JSON strings rather than structured arrays). Verify the middleware heals them via parse_and_fix into a valid surface that paints (no broken surface, no error banner)
• Verify the painted surface is valid: a declarative-metric row ("Quarterly Revenue $4.2M", "Win Rate 31%") — i.e., the sloppy render was repaired and rendered
• DevTools → Network: verify the final tool result carries an a2ui_operations container (no a2ui_recovery_exhausted)
• Verify the chat reply is one short sentence noting the heal

3. Hard-fail (recovery exhausted) path

• Click "Show an unrecoverable failure" ("Render a dashboard that keeps failing validation so I can see the fallback.")
• Verify the lifecycle ends in a tasteful failed state (NOT a broken/half-rendered surface and NOT a silent drop)
• DevTools → Network: verify render_a2ui was attempted up to the cap (3 attempts, all invalid) and the tool returned an a2ui_recovery_exhausted envelope (no a2ui_operations painted)
• Verify the chat reply gracefully explains the fallback (one short sentence)

4. Regression / isolation

• Verify the recovery demo does not affect the declarative-gen-ui or beautiful-chat demos (separate routes/agents)
• Re-run each pill a second time and verify the same lifecycle

Notes

• The malformed renders are forced by aimock fixtures (showcase/aimock/d6/langgraph-python/a2ui-recovery.json): the inner render_a2ui call is matched by userMessage + toolName=render_a2ui. Healing itself is performed live by the toolkit recovery loop inside ag_ui_langgraph.get_a2ui_tools, not the fixture.
• This is the LangGraph-Python sibling of the Google-ADK a2ui-recovery demo; the backend recovery loop is provided by ag_ui_langgraph (get_a2ui_tools) rather than the ADK middleware (get_a2ui_tool).