showcase/integrations/strands/PARITY_NOTES.md
This file documents the status of each showcase demo relative to the
canonical LangGraph-Python showcase package (showcase/integrations/langgraph-python).
The overall architectural difference between the two packages:
src/agents/<demo>.py module per demo, each
bound to its own LangGraph graph via langgraph.json.src/agents/agent.py)
registered under many agent names in the AG-UI runtime. All demos in the
Strands package reuse the same backend; per-demo differentiation happens
almost entirely on the frontend via useFrontendTool, useRenderTool,
useHumanInTheLoop, useAgentContext, and A2UI catalogs.This keeps the Strands code base dramatically smaller without sacrificing user-visible functionality — the demo URLs, pages, and interactive flows are all present.
These demos depend on LangGraph-specific primitives that AWS Strands does not expose at this time:
useLangGraphInterrupt, which hooks directly
into the LangGraph interrupt lifecycle. Strands does not provide an
equivalent first-class interrupt primitive. The ergonomic replacement is
hitl-in-chat (implemented), which uses useHumanInTheLoop on top of a
regular frontend tool — Strands supports that natively. Surfaced as a stub
page (src/app/demos/gen-ui-interrupt/) and as
not_supported_features.gen-ui-interrupt in the manifest.gen-ui-interrupt. Requires
useLangGraphInterrupt's resolve/respond primitive. Not portable.
Surfaced as a stub page (src/app/demos/interrupt-headless/) and as
not_supported_features.interrupt-headless in the manifest./api/copilotkit-mcp-apps route configures
mcpApps.servers: [{ type: "http", url: ..., serverId: "excalidraw" }].
The Strands shared agent has no bespoke MCP tools — the runtime
middleware advertises the MCP server's tools to the agent at request
time and emits the activity events that CopilotKit's built-in
MCPAppsActivityRenderer paints inline as a sandboxed iframe. Mirrors
the langgraph-python sibling pattern.Wave-2 port status for the previously deferred demos:
/api/copilotkit-byoc-hashbrown
route, hashbrown renderer + catalog, MetricCard/PieChart/BarChart/DealCard
components. The strict hashbrown JSON envelope prompt lives in
src/agents/byoc_hashbrown.py and is injected into the shared Strands
agent as useAgentContext. Incorporates PR #4271 fix from the start
(JSON envelope — NOT XML)./api/copilotkit-byoc-json-render
route, @json-render/react renderer with <JSONUIProvider> wrap (PR #4271
fix). Registry forwards children through the MetricCard wrapper so
nested dashboards render. Output prompt lives in
src/agents/byoc_json_render.py and is mirrored on the frontend via
useAgentContext./api/copilotkit-ogui route with
openGenerativeUI: { agents: ["open-gen-ui", "open-gen-ui-advanced"] }.
Minimal variant uses openGenerativeUI.designSkill to steer the LLM
toward intricate, educational visualisations.openGenerativeUI.sandboxFunctions (evaluateExpression, notifyHost) so
the agent-authored iframe can invoke host functions via
Websandbox.connection.remote.<name>(...).showcase/integrations/spring-ai/src/app/demos/beautiful-chat/).
Porting the full canonical surface (ExampleCanvas, GenerativeUIExamples,
declarative A2UI catalog, theme provider, dedicated runtime that
enables openGenerativeUI + a2ui + mcpApps simultaneously) remains
out-of-scope future work — see the LangGraph-Python reference in
showcase/integrations/langgraph-python/src/app/demos/beautiful-chat/
for the full surface area.The Strands showcase uses one shared Strands Agent backend
(agent_server.py). Wave-2's BYOC demos specialize the LLM's output shape
(hashbrown envelope / json-render spec) by injecting the canonical system
prompt via useAgentContext on the frontend, rather than by spinning up
dedicated Strands Agent instances per demo. The canonical prompts live in
src/agents/byoc_hashbrown.py and src/agents/byoc_json_render.py as the
single source of truth; the frontend strings mirror them. This keeps the
Strands backend topology simple while letting each demo specialize its
output contract.
All other LangGraph-Python demos are ported below.
Existing (pre-blitz):
agentic-chat, hitl (ergonomic HITL), tool-rendering, gen-ui-tool-based,
gen-ui-agent, shared-state-read-write, shared-state-streaming, subagents.Added in this blitz:
cli-start — manifest-only start command.chat-customization-css — scoped CSS re-theme of <CopilotChat />.prebuilt-sidebar — <CopilotSidebar />.prebuilt-popup — <CopilotPopup />.chat-slots — slot-system chat customization.headless-simple — minimal chat built on useAgent.headless-complete — full headless chat implementation.agentic-chat-reasoning — reasoning chain rendered via a custom slot.reasoning-default-render — built-in CopilotChatReasoningMessage render.frontend-tools — useFrontendTool background-change demo.frontend-tools-async — async useFrontendTool handler.hitl-in-chat — useHumanInTheLoop ergonomic HITL.hitl-in-app — app-level modal HITL via async useFrontendTool.tool-rendering-default-catchall — zero-config wildcard tool render.tool-rendering-custom-catchall — branded wildcard renderer via useDefaultRenderTool.tool-rendering-reasoning-chain — tool renders + reasoning tokens side-by-side.readonly-state-agent-context — useAgentContext read-only context.declarative-gen-ui — dynamic A2UI via custom catalog.a2ui-fixed-schema — A2UI rendered against a known client-side schema.multimodal — image + PDF attachments.auth — bearer-token gated runtime.voice — voice input via @copilotkit/voice.agent-config — typed config object forwarded to agent.gen-ui-tool-based — tool-triggered generative UI (haiku generator) via
useFrontendTool with a custom render. Manifest entry added; the page
was already in place from a prior wave.tool-rendering-default-catchall — zero-config wildcard tool render via
useDefaultRenderTool(). Manifest entry added; page already shipped.tool-rendering-custom-catchall — branded wildcard render. Manifest
entry added; page already shipped.hitl-in-chat-booking — manifest alias of hitl-in-chat; both feature
ids point to the same /demos/hitl-in-chat route, mirroring the
langgraph-python manifest topology so the harness's per-feature live
status surfaces the booking flow as its own row.The Strands shared agent (src/agents/agent.py) already exposes the tools
all of the above need (weather, flights, query_data, schedule_meeting,
manage_sales_todos, set_theme_color, generate_a2ui). New demos that need
additional agent-side surface are documented inline in their respective demo
folders.