wehub-resource-sync
980 lines
40 KiB
Python
980 lines
40 KiB
Python
"""
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CopilotKit Middleware for LangGraph agents.
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Works with any agent (prebuilt or custom).
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Example:
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from langgraph.prebuilt import create_agent
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from copilotkit import CopilotKitMiddleware
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agent = create_agent(
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model="openai:gpt-4o",
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tools=[backend_tool],
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middleware=[CopilotKitMiddleware()],
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)
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"""
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import json
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import re
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from typing import Any, Callable, Awaitable, ClassVar, Iterable, Optional, Union
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from langchain_core.messages import AIMessage, SystemMessage, ToolMessage
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from langchain.agents.middleware import (
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AgentMiddleware,
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AgentState,
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ModelRequest,
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ModelResponse,
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)
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from langgraph.runtime import Runtime
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from .header_propagation import install_httpx_hook, set_forwarded_headers
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from .langgraph import CopilotKitProperties
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# Optional dependency: the A2UI subagent-tool factory ships in ag-ui-langgraph.
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# Guarded so an older/skewed version without the factory degrades to
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# "no auto-A2UI" instead of breaking the whole middleware import.
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try: # pragma: no cover - exercised indirectly via the a2ui injection path
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from ag_ui_langgraph import get_a2ui_tools, A2UIToolParams
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except Exception: # noqa: BLE001 - any import failure means the feature is off
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get_a2ui_tools = None
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A2UIToolParams = None
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# Track which httpx clients already have the header-propagation hook installed
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# (by object id) so we never double-install on repeated model calls.
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_hooked_clients: set[int] = set()
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# ---------------------------------------------------------------------------
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# Auto-A2UI: bridge the inferred model from the model-call hook to the
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# tool-call hook
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# ---------------------------------------------------------------------------
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# The generate_a2ui tool drives a structured-output subagent and so needs a
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# chat model. We "infer" that model from ``request.model`` in
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# ``wrap_model_call`` (the only hook that exposes the bound model) and reuse it.
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# But the tool actually *executes* later in ``wrap_tool_call``, whose request
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# does NOT carry the model. ContextVars do not reliably survive LangGraph node
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# boundaries, so we bridge the built tool across nodes via a module-level map
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# keyed by the run's thread id.
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_a2ui_tools_by_thread: dict[str, Any] = {}
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# Fallback key for runs without a thread id (e.g. an in-memory invoke with no
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# checkpointer). Collisions across concurrent context-less runs are an
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# acceptable edge — the deployed path always carries a thread id.
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_DEFAULT_THREAD_KEY = "__copilotkit_a2ui_default__"
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def _current_thread_id() -> "str | None":
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"""Best-effort read of the active run's thread id from the LangGraph config.
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Returns ``None`` outside a runnable context (e.g. unit tests); callers then
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fall back to ``_DEFAULT_THREAD_KEY``.
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"""
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try:
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from langgraph.config import get_config
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cfg = get_config() or {}
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return (cfg.get("configurable") or {}).get("thread_id")
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except Exception: # noqa: BLE001 - no active context / older langgraph
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return None
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def _extract_forwarded_headers_from_config() -> None:
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"""Extract raw ``x-*`` headers from the current LangGraph RunnableConfig and
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push them into the header-propagation ContextVar so the httpx hook can
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forward them on outgoing LLM requests.
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When an agent runs inside **langgraph-api** with
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``LANGGRAPH_HTTP={"configurable_headers":{"include":["x-*"]}}``,
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the server copies inbound HTTP ``x-*`` headers into
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``config["configurable"]`` as individual keys (e.g.
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``configurable["x-aimock-context"] = "value"``). This function reads those
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keys and calls :func:`set_forwarded_headers` so they propagate to the
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underlying LLM provider SDK via the httpx event hook.
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Precedence: the wrapper dict ``copilotkit_forwarded_headers`` (if present)
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takes priority over raw ``x-*`` keys. Raw keys are only used when the
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wrapper dict is absent or does not contain a given header.
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Safe to call outside a runnable context (e.g. in unit tests) — silently
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returns without doing anything if ``get_config()`` raises.
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"""
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try:
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from langgraph.config import (
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get_config,
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) # local import to avoid hard dep at module level
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config = get_config()
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except ImportError:
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return
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except RuntimeError:
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# No active runnable context — clear the ContextVar so stale headers
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# from a prior request in the same async context do not leak through.
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set_forwarded_headers({})
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return
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try:
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headers: dict[str, str] = {}
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# Sources to scan: config["context"] (LangGraph >=0.6.0) and
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# config["configurable"] (all versions).
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context = config.get("context") or {}
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configurable = config.get("configurable") or {}
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# 1) Wrapper-dict path (highest priority): these are headers that
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# CopilotKit explicitly bundled under a known key. Process context
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# first with first-write-wins so context takes precedence over
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# configurable (LangGraph >=0.6.0 introduced context as the newer
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# preferred mechanism).
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for src in (context, configurable):
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if not isinstance(src, dict):
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continue
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wrapper = src.get("copilotkit_forwarded_headers")
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if isinstance(wrapper, dict):
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for k, v in wrapper.items():
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lk = k.lower() if isinstance(k, str) else k
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if isinstance(k, str) and isinstance(v, str) and lk not in headers:
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headers[lk] = v
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# 2) Raw x-* keys directly on context and configurable. These appear
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# when langgraph-api's configurable_headers mechanism forwards inbound
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# HTTP headers as individual configurable entries.
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for src in (context, configurable):
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if not isinstance(src, dict):
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continue
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for k, v in src.items():
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if (
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isinstance(k, str)
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and k.lower().startswith("x-")
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and isinstance(v, str)
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):
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# Don't overwrite wrapper-dict values (wrapper > raw).
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# Lowercase at insertion so precedence checks are
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# deterministic regardless of source casing.
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lk = k.lower()
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if lk not in headers:
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headers[lk] = v
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# Always set the ContextVar — even with an empty dict — so stale
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# headers from previous calls in the same async context do not leak
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# into this one.
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set_forwarded_headers(headers)
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except Exception as e:
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# Header forwarding is best-effort. Never block the LLM call.
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# Clear the ContextVar so stale headers from a prior request do not
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# leak through on failure.
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set_forwarded_headers({})
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import logging
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logging.getLogger(__name__).debug(
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"Header forwarding extraction failed; continuing without forwarded headers: %s",
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e,
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)
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def _ensure_httpx_hook(model: Any) -> None:
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"""Install the header-propagation httpx hook on a LangChain chat model's
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underlying HTTP client(s), if present. No-op for models that don't expose
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an httpx transport (e.g. non-OpenAI/Anthropic providers).
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"""
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for attr in ("client", "async_client"):
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client = getattr(model, attr, None)
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if client is None:
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continue
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cid = id(client)
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if cid not in _hooked_clients:
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install_httpx_hook(client)
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_hooked_clients.add(cid)
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class StateSchema(AgentState):
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copilotkit: CopilotKitProperties
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StateSchema.__annotations__["ag-ui"] = CopilotKitProperties
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# Internal/framework keys that should never be surfaced to the LLM as
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# user-facing state. These are either reducer-managed message buckets,
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# CopilotKit/AG-UI plumbing, or graph-internal scaffolding.
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_RESERVED_STATE_KEYS = frozenset(
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{
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"messages",
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"copilotkit",
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# Transport-layer plumbing: forwarded request headers conveyed via a
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# separate ContextVar to the httpx hook. MUST never be rendered into
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# the LLM prompt — neither via App Context nor via expose_state.
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"copilotkit_forwarded_headers",
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"ag-ui",
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"tools",
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"structured_response",
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"thread_id",
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"remaining_steps",
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}
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)
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class CopilotKitMiddleware(AgentMiddleware[StateSchema, Any]):
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"""CopilotKit Middleware for LangGraph agents.
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Handles frontend tool injection, interception for CopilotKit, and
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automatic exposure of agent state to the LLM so values written via
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``agent.setState`` on the frontend (or via ``Command(update=...)`` in a
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tool) are visible in the next model call without needing a custom
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``get_state`` tool.
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Args:
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expose_state: Controls how user-defined state keys are surfaced into
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``request.system_message`` on every model call. Off by default
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to avoid leaking arbitrary state into prompts; opt in explicitly.
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- ``False`` (default) — never surface state.
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- ``True`` — every state key that is not in the reserved
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internal set and does not start with an underscore is
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JSON-serialized into a "Current agent state:" note appended
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to the system message.
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- ``list``/``tuple``/``set[str]`` — only surface the named keys.
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Use this when you want explicit control over what the LLM
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sees (e.g. ``["liked", "todos"]``).
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a2ui_params: Optional host overrides for the auto-injected
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``generate_a2ui`` tool, forwarded to ``get_a2ui_tools`` when A2UI
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injection fires. An ``A2UIToolParams``-shaped dict: ``guidelines``
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(``generation_guidelines`` / ``design_guidelines`` /
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``composition_guide``), ``default_catalog_id``,
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``default_surface_id``, ``tool_name``, ``recovery``, etc. Lets a
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host steer the subagent (e.g. override the default design
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guidelines to favor a repeating-card layout) on the auto-inject
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path, which otherwise only ever uses the toolkit defaults.
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The middleware always injects ``model`` from the bound request
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model (the host cannot supply the live, header-hooked model), and
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folds the registered catalog id + component schema into the params
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unless the host already set them — so host values win.
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"""
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state_schema = StateSchema
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tools: ClassVar[list] = []
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def __init__(
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self,
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*,
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expose_state: Union[bool, Iterable[str]] = False,
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a2ui_params: "Optional[A2UIToolParams]" = None,
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):
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super().__init__()
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if isinstance(expose_state, bool):
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self._expose_state: Union[bool, frozenset[str]] = expose_state
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else:
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self._expose_state = frozenset(expose_state)
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# Host-supplied A2UI tool overrides (guidelines, catalog id, tool name,
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# recovery, ...). Copied so later mutation of the caller's dict can't
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# bleed into the middleware. ``model`` + the registered catalog are
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# layered in at build time; everything here is host-owned and wins.
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self._a2ui_params: dict = dict(a2ui_params or {})
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@property
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def name(self) -> str:
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return "CopilotKitMiddleware"
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# ------------------------------------------------------------------
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# State-to-prompt surfacing
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# ------------------------------------------------------------------
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def _build_state_note(self, state: dict) -> str | None:
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"""Serialize a snapshot of user state into a system-prompt note.
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Returns ``None`` when nothing should be appended (feature disabled
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or no non-empty user keys present).
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"""
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if self._expose_state is False:
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return None
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if isinstance(self._expose_state, frozenset):
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# Allowlist branch: honor user intent for other reserved keys
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# (e.g. ``thread_id``) so the override test in this suite still
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# passes, but hard-exclude ``copilotkit_forwarded_headers`` —
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# rendering it would leak the raw forwarded request headers into
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# the LLM prompt, which is what the reserved-keys comment above
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# promises will never happen "via App Context nor via expose_state".
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keys: list[str] = [
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k
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for k in self._expose_state
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if k in state and k != "copilotkit_forwarded_headers"
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]
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else:
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keys = [
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k
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for k in state
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if k not in _RESERVED_STATE_KEYS and not str(k).startswith("_")
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]
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snapshot: dict[str, Any] = {}
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for k in keys:
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v = state.get(k)
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# Skip empty / no-op values to keep the note tight.
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if v in (None, "", [], {}):
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continue
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snapshot[k] = v
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if not snapshot:
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return None
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try:
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body = json.dumps(snapshot, default=str, ensure_ascii=False, indent=2)
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except (TypeError, ValueError):
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body = str(snapshot)
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return f"Current agent state:\n{body}"
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def _apply_state_note(self, request: ModelRequest) -> ModelRequest:
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note = self._build_state_note(request.state or {})
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if not note:
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return request
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existing = request.system_message
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if existing is None:
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return request.override(system_message=SystemMessage(content=note))
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base = (
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existing.content
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if isinstance(existing.content, str)
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else str(existing.content)
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)
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return request.override(
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system_message=SystemMessage(content=f"{base}\n\n{note}")
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)
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# ------------------------------------------------------------------
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# Auto-A2UI tool injection
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# ------------------------------------------------------------------
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@staticmethod
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def _resolve_a2ui_catalog(state: dict) -> "tuple[str | None, str | None] | None":
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"""Find the frontend-registered A2UI catalog wherever it was passed.
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Returns ``(component_schema, catalog_id)`` when a catalog is present,
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else ``None`` (so the tool is never advertised when the client can't
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render A2UI). Two delivery paths are supported, because the catalog
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lands in different places depending on how the agent is served:
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- **AG-UI native endpoint** → ``state["ag-ui"]["a2ui_schema"]``, a JSON
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string ``{"catalogId": ..., "components": [...]}``.
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- **CopilotKit runtime proxy** → a ``state["copilotkit"]["context"]``
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entry describing the A2UI catalog (catalog id + component schemas as
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text).
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``component_schema`` is the text/JSON the subagent should compose from;
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``catalog_id`` binds generated surfaces to the frontend's catalog (so
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BYOC custom catalogs render their own components, not the basic one).
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"""
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# AG-UI native path.
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ag_ui = state.get("ag-ui") or {}
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a2ui_schema = ag_ui.get("a2ui_schema")
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if a2ui_schema:
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catalog_id = None
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try:
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parsed = (
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json.loads(a2ui_schema)
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if isinstance(a2ui_schema, str)
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else a2ui_schema
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)
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if isinstance(parsed, dict):
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catalog_id = parsed.get("catalogId")
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except (TypeError, ValueError):
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pass
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# Native path: the toolkit reads ``a2ui_schema`` from state itself,
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# so no composition_guide is needed — just surface the catalog id.
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return None, catalog_id
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# CopilotKit runtime-proxy path: the catalog arrives as a context entry.
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context = (state.get("copilotkit") or {}).get("context") or []
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for entry in context:
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if not isinstance(entry, dict):
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continue
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description = entry.get("description") or ""
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value = entry.get("value") or ""
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if "A2UI catalog" not in description or not value:
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continue
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# The value lists catalogs as "- <catalogId>" lines; the first is
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# the custom catalog the client registered.
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match = re.search(r"(?m)^\s*-\s+(\S+)", value)
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catalog_id = match.group(1) if match else None
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return value, catalog_id
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return None
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@staticmethod
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def _a2ui_inject_decision(state: dict) -> "bool | str | None":
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"""Return the A2UI ``injectA2UITool`` decision, or ``None``.
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The ``@ag-ui/a2ui-middleware`` forwards its ``injectA2UITool`` setting on
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``forwardedProps``, which ``ag-ui-langgraph`` surfaces into agent state at
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``state["ag-ui"]["inject_a2ui_tool"]`` — present only when the host turned
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the runtime A2UI tool on (truthy or a custom tool-name string). ``None``
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means no signal at all (off, or no A2UI middleware in the pipeline), in
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which case we do not auto-inject.
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"""
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return (state.get("ag-ui") or {}).get("inject_a2ui_tool")
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def _maybe_build_a2ui_tool(self, request: ModelRequest) -> Any | None:
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"""Build a ``generate_a2ui`` tool bound to the agent's own model when
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A2UI tool injection is turned on for this run.
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Gating, in order:
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1. **Opt-in.** Only inject when the A2UI ``injectA2UITool`` flag is
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truthy (forwarded by ``@ag-ui/a2ui-middleware`` and surfaced at
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``state["ag-ui"]["inject_a2ui_tool"]``). No flag → no injection. This
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is the whole contract: "no injectA2UITool, no A2UI tool injection."
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2. **No double-inject.** If the agent already exposes a tool with the
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same name (e.g. a backend-defined ``generate_a2ui``), don't inject —
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the host owns it, and a duplicate would show the model two tools with
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one name.
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The model is inferred from ``request.model`` (the bound agent model); the
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component schema and catalog id come from the registered catalog (when
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present) so the subagent composes the right components and surfaces bind
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to the frontend's catalog — otherwise the toolkit's basic catalog is
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used. The built tool is stashed for the tool-call hook to execute.
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Returns the tool or ``None`` when A2UI is not applicable.
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"""
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if get_a2ui_tools is None:
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return None
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state = request.state or {}
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# (1) Opt-in: only inject when the host turned the A2UI tool on.
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if not self._a2ui_inject_decision(state):
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return None
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# Bind to the frontend's catalog when one was registered (optional).
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resolved = self._resolve_a2ui_catalog(state)
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component_schema, catalog_id = resolved if resolved else (None, None)
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# Shared A2UIToolParams: a single params object owned by the toolkit.
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# Start from the host overrides (guidelines / catalog id / tool name /
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# recovery) so a host can steer the subagent, then layer in only what
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# the host cannot know — the bound model, and the registered catalog id
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# + component schema — without clobbering any host-set value.
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params: "A2UIToolParams" = dict(self._a2ui_params)
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params["model"] = request.model
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if catalog_id and "default_catalog_id" not in params:
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params["default_catalog_id"] = catalog_id
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# Feed the registered component schema to the subagent so it composes
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# only catalog components (the toolkit appends this to its prompt).
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# Merge into any host ``guidelines`` bag; a host-set composition_guide
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# wins, and host generation/design overrides are preserved.
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if component_schema:
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guidelines = dict(params.get("guidelines") or {})
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guidelines.setdefault("composition_guide", component_schema)
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params["guidelines"] = guidelines
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tool = get_a2ui_tools(params)
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# (2) Don't double-inject if the agent already defines this tool.
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existing_names = {getattr(t, "name", None) for t in (request.tools or [])}
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if tool.name in existing_names:
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return None
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_a2ui_tools_by_thread[_current_thread_id() or _DEFAULT_THREAD_KEY] = tool
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|
return tool
|
|
|
|
# Inject frontend + A2UI tools and surface user state before model call
|
|
def wrap_model_call(
|
|
self,
|
|
request: ModelRequest,
|
|
handler: Callable[[ModelRequest], ModelResponse],
|
|
) -> ModelResponse:
|
|
_extract_forwarded_headers_from_config()
|
|
_ensure_httpx_hook(request.model)
|
|
request = self._apply_state_note(request)
|
|
|
|
a2ui_tool = self._maybe_build_a2ui_tool(request)
|
|
frontend_tools = request.state.get("copilotkit", {}).get("actions", [])
|
|
if a2ui_tool is not None:
|
|
# Our generate_a2ui replaces the runtime's render tool — don't
|
|
# advertise both. Drop the render tool the A2UI middleware injected.
|
|
decision = self._a2ui_inject_decision(request.state or {})
|
|
drop = decision if isinstance(decision, str) else "render_a2ui"
|
|
frontend_tools = [
|
|
t
|
|
for t in frontend_tools
|
|
if ((t.get("function") or {}).get("name") or t.get("name")) != drop
|
|
]
|
|
|
|
if not frontend_tools and a2ui_tool is None:
|
|
return handler(request)
|
|
|
|
extra_tools = [a2ui_tool] if a2ui_tool is not None else []
|
|
merged_tools = [*request.tools, *extra_tools, *frontend_tools]
|
|
|
|
return handler(request.override(tools=merged_tools))
|
|
|
|
@staticmethod
|
|
def _fix_messages_for_bedrock(messages: list) -> list:
|
|
"""Fix messages loaded from checkpoint before sending to Bedrock.
|
|
|
|
Handles four issues caused by CopilotKit's after_agent restoring
|
|
frontend tool_calls to the checkpoint:
|
|
1. Strip unanswered tool_calls (no matching ToolMessage) — Bedrock
|
|
rejects toolUse without a corresponding toolResult.
|
|
2. Sync msg.content tool_use blocks with msg.tool_calls.
|
|
3. Fix tool_use content blocks with string input (must be dict).
|
|
4. Deduplicate ToolMessages by tool_call_id — patch_orphan_tool_calls
|
|
injects a placeholder with a new random ID on every checkpoint load;
|
|
when the real result is later appended alongside it, Bedrock rejects
|
|
the duplicate toolResult IDs. We keep the real result (non-interrupted)
|
|
over the placeholder, falling back to the last occurrence if both look
|
|
real.
|
|
"""
|
|
# 4. Deduplicate ToolMessages by tool_call_id before all other processing.
|
|
# patch_orphan_tool_calls adds "…was interrupted before completion."
|
|
# placeholders with fresh random IDs on every checkpoint load. The real
|
|
# result comes in as a separate message with a different ID, so both end
|
|
# up in the list. Keep the real (non-interrupted) one; if multiple real
|
|
# ones exist, keep the last.
|
|
_INTERRUPTED_PAT = re.compile(
|
|
r"^Tool call '.+' with id '.+' was interrupted before completion\.$"
|
|
)
|
|
# Group ToolMessages by tool_call_id, preserving position
|
|
tc_groups: dict[str, list] = {}
|
|
for i, msg in enumerate(messages):
|
|
if isinstance(msg, ToolMessage):
|
|
tc_id = getattr(msg, "tool_call_id", None)
|
|
if tc_id:
|
|
tc_groups.setdefault(tc_id, []).append(i)
|
|
|
|
drop_indices: set = set()
|
|
for tc_id, indices in tc_groups.items():
|
|
if len(indices) <= 1:
|
|
continue
|
|
# Separate interrupted placeholders from real results
|
|
real_indices = [
|
|
i
|
|
for i in indices
|
|
if not (
|
|
isinstance(messages[i].content, str)
|
|
and _INTERRUPTED_PAT.match(messages[i].content)
|
|
)
|
|
]
|
|
interrupted_indices = [i for i in indices if i not in real_indices]
|
|
if real_indices and interrupted_indices:
|
|
# Replace the first placeholder (correct position, adjacent to AI
|
|
# message) with the last real result (likely appended at the end).
|
|
# This keeps the tool result in the right position for Bedrock.
|
|
messages[interrupted_indices[0]] = messages[real_indices[-1]]
|
|
drop_indices.update(interrupted_indices[1:])
|
|
drop_indices.update(real_indices) # drop all originals (we moved one)
|
|
elif real_indices:
|
|
# No placeholders, multiple real — keep only the last
|
|
drop_indices.update(real_indices[:-1])
|
|
else:
|
|
# All interrupted — keep only the last
|
|
drop_indices.update(interrupted_indices[:-1])
|
|
|
|
if drop_indices:
|
|
messages[:] = [
|
|
msg for i, msg in enumerate(messages) if i not in drop_indices
|
|
]
|
|
|
|
for idx, msg in enumerate(messages):
|
|
if not isinstance(msg, AIMessage):
|
|
continue
|
|
|
|
tool_calls = getattr(msg, "tool_calls", None) or []
|
|
|
|
# 1. Sync content with tool_calls: remove tool_use content blocks
|
|
# that aren't in msg.tool_calls (e.g. stripped by after_model
|
|
# but content blocks left behind in checkpoint).
|
|
if tool_calls and isinstance(msg.content, list):
|
|
tc_ids = {tc.get("id") for tc in tool_calls}
|
|
msg.content = [
|
|
block
|
|
for block in msg.content
|
|
if not (
|
|
isinstance(block, dict)
|
|
and block.get("type") == "tool_use"
|
|
and block.get("id") not in tc_ids
|
|
)
|
|
]
|
|
elif not tool_calls and isinstance(msg.content, list):
|
|
# No tool_calls at all — strip ALL tool_use content blocks
|
|
msg.content = [
|
|
block
|
|
for block in msg.content
|
|
if not (isinstance(block, dict) and block.get("type") == "tool_use")
|
|
]
|
|
|
|
if not tool_calls:
|
|
continue
|
|
|
|
# 2. Strip unanswered tool_calls — only consider ToolMessages that
|
|
# are ADJACENT (immediately following this AIMessage, before the
|
|
# next non-ToolMessage). A ToolMessage at the wrong position
|
|
# won't satisfy Bedrock's Converse API requirement that toolResult
|
|
# blocks appear in the user turn right after the assistant turn.
|
|
adjacent_tc_ids: set = set()
|
|
j = idx + 1
|
|
while j < len(messages) and isinstance(messages[j], ToolMessage):
|
|
tc_id = getattr(messages[j], "tool_call_id", None)
|
|
if tc_id:
|
|
adjacent_tc_ids.add(tc_id)
|
|
j += 1
|
|
|
|
unanswered = [
|
|
tc for tc in tool_calls if tc.get("id") not in adjacent_tc_ids
|
|
]
|
|
if unanswered:
|
|
unanswered_ids = {tc["id"] for tc in unanswered}
|
|
msg.tool_calls = [
|
|
tc for tc in tool_calls if tc.get("id") in adjacent_tc_ids
|
|
]
|
|
|
|
# Also strip matching content blocks
|
|
if isinstance(msg.content, list):
|
|
msg.content = [
|
|
block
|
|
for block in msg.content
|
|
if not (
|
|
isinstance(block, dict)
|
|
and block.get("type") == "tool_use"
|
|
and block.get("id") in unanswered_ids
|
|
)
|
|
]
|
|
|
|
# 3. Fix string args in tool_calls
|
|
for tc in msg.tool_calls or []:
|
|
if isinstance(tc.get("args"), str):
|
|
try:
|
|
tc["args"] = json.loads(tc["args"])
|
|
except (json.JSONDecodeError, TypeError):
|
|
tc["args"] = {}
|
|
|
|
# 4. Fix string input in content blocks
|
|
if isinstance(msg.content, list):
|
|
for block in msg.content:
|
|
if isinstance(block, dict) and block.get("type") == "tool_use":
|
|
inp = block.get("input")
|
|
if isinstance(inp, str):
|
|
try:
|
|
block["input"] = json.loads(inp) if inp else {}
|
|
except (json.JSONDecodeError, TypeError):
|
|
block["input"] = {}
|
|
elif inp is None:
|
|
block["input"] = {}
|
|
|
|
# 5. Remove orphan ToolMessages whose tool_call_id no longer matches
|
|
# any remaining tool_call in any AIMessage. These can be left over
|
|
# after stripping unanswered tool_calls above.
|
|
remaining_tc_ids: set = set()
|
|
for msg in messages:
|
|
if isinstance(msg, AIMessage):
|
|
for tc in getattr(msg, "tool_calls", None) or []:
|
|
tc_id = tc.get("id")
|
|
if tc_id:
|
|
remaining_tc_ids.add(tc_id)
|
|
messages[:] = [
|
|
msg
|
|
for msg in messages
|
|
if not isinstance(msg, ToolMessage)
|
|
or getattr(msg, "tool_call_id", None) in remaining_tc_ids
|
|
]
|
|
|
|
return messages
|
|
|
|
async def awrap_model_call(
|
|
self,
|
|
request: ModelRequest,
|
|
handler: Callable[[ModelRequest], Awaitable[ModelResponse]],
|
|
) -> ModelResponse:
|
|
_extract_forwarded_headers_from_config()
|
|
_ensure_httpx_hook(request.model)
|
|
self._fix_messages_for_bedrock(request.messages)
|
|
request = self._apply_state_note(request)
|
|
|
|
a2ui_tool = self._maybe_build_a2ui_tool(request)
|
|
frontend_tools = request.state.get("copilotkit", {}).get("actions", [])
|
|
if a2ui_tool is not None:
|
|
# Our generate_a2ui replaces the runtime's render tool — don't
|
|
# advertise both. Drop the render tool the A2UI middleware injected.
|
|
decision = self._a2ui_inject_decision(request.state or {})
|
|
drop = decision if isinstance(decision, str) else "render_a2ui"
|
|
frontend_tools = [
|
|
t
|
|
for t in frontend_tools
|
|
if ((t.get("function") or {}).get("name") or t.get("name")) != drop
|
|
]
|
|
|
|
if not frontend_tools and a2ui_tool is None:
|
|
return await handler(request)
|
|
|
|
extra_tools = [a2ui_tool] if a2ui_tool is not None else []
|
|
merged_tools = [*request.tools, *extra_tools, *frontend_tools]
|
|
|
|
return await handler(request.override(tools=merged_tools))
|
|
|
|
# ------------------------------------------------------------------
|
|
# Auto-A2UI tool execution
|
|
# ------------------------------------------------------------------
|
|
# The generate_a2ui tool is advertised dynamically in wrap_model_call and is
|
|
# NOT in create_agent's static tool registry, so the tool node cannot
|
|
# execute it on its own. These hooks supply the implementation (built with
|
|
# the inferred model) for that one tool; their presence also disables
|
|
# create_agent's "unknown tool" guard for dynamically-advertised tools.
|
|
|
|
def _resolve_a2ui_request(self, request: Any) -> Any:
|
|
"""Return a request overridden with the stashed A2UI tool when this
|
|
tool call targets it, else the original request unchanged."""
|
|
tool = _a2ui_tools_by_thread.get(_current_thread_id() or _DEFAULT_THREAD_KEY)
|
|
if (
|
|
tool is not None
|
|
and getattr(request, "tool", None) is None
|
|
and request.tool_call.get("name") == tool.name
|
|
):
|
|
return request.override(tool=tool)
|
|
return request
|
|
|
|
def wrap_tool_call(
|
|
self,
|
|
request: Any,
|
|
handler: Callable[[Any], Any],
|
|
) -> Any:
|
|
return handler(self._resolve_a2ui_request(request))
|
|
|
|
async def awrap_tool_call(
|
|
self,
|
|
request: Any,
|
|
handler: Callable[[Any], Awaitable[Any]],
|
|
) -> Any:
|
|
return await handler(self._resolve_a2ui_request(request))
|
|
|
|
# Inject app context before agent runs
|
|
def before_agent(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
messages = state.get("messages", [])
|
|
|
|
if not messages:
|
|
return None
|
|
|
|
# Get app context from state or runtime
|
|
copilotkit_state = state.get("copilotkit", {})
|
|
app_context = copilotkit_state.get("context") or getattr(
|
|
runtime, "context", None
|
|
)
|
|
|
|
# Strip the reserved transport-layer key ``copilotkit_forwarded_headers``
|
|
# so it is never rendered into the LLM prompt. langgraph-api auto-copies
|
|
# ``config.configurable`` into ``runtime.context``, which means the
|
|
# forwarded-headers wrapper dict shows up here even though it is only
|
|
# meant for the httpx hook (which reads it from a separate ContextVar
|
|
# via ``_extract_forwarded_headers_from_config``).
|
|
if isinstance(app_context, dict):
|
|
app_context = {
|
|
k: v
|
|
for k, v in app_context.items()
|
|
if k != "copilotkit_forwarded_headers"
|
|
}
|
|
|
|
# Check if app_context is missing or empty
|
|
if not app_context:
|
|
return None
|
|
if isinstance(app_context, str) and app_context.strip() == "":
|
|
return None
|
|
if isinstance(app_context, dict) and len(app_context) == 0:
|
|
return None
|
|
|
|
# Create the context content
|
|
if isinstance(app_context, str):
|
|
context_content = app_context
|
|
else:
|
|
# Handle Pydantic models (e.g. ag_ui Context)
|
|
if hasattr(app_context, "model_dump"):
|
|
app_context = app_context.model_dump()
|
|
elif isinstance(app_context, list):
|
|
app_context = [
|
|
item.model_dump() if hasattr(item, "model_dump") else item
|
|
for item in app_context
|
|
]
|
|
context_content = json.dumps(app_context, indent=2)
|
|
|
|
context_message_content = f"App Context:\n{context_content}"
|
|
context_message_prefix = "App Context:\n"
|
|
|
|
# Helper to get message content as string
|
|
def get_content_string(msg: Any) -> str | None:
|
|
content = getattr(msg, "content", None)
|
|
if isinstance(content, str):
|
|
return content
|
|
if isinstance(content, list) and content and isinstance(content[0], dict):
|
|
return content[0].get("text")
|
|
return None
|
|
|
|
# Find the first system/developer message (not our context message)
|
|
# to determine where to insert our context message (right after it)
|
|
first_system_index = -1
|
|
|
|
for i, msg in enumerate(messages):
|
|
msg_type = getattr(msg, "type", None)
|
|
if msg_type in ("system", "developer"):
|
|
content = get_content_string(msg)
|
|
# Skip if this is our own context message
|
|
if content and content.startswith(context_message_prefix):
|
|
continue
|
|
first_system_index = i
|
|
break
|
|
|
|
# Check if our context message already exists
|
|
existing_context_index = -1
|
|
for i, msg in enumerate(messages):
|
|
msg_type = getattr(msg, "type", None)
|
|
if msg_type in ("system", "developer"):
|
|
content = get_content_string(msg)
|
|
if content and content.startswith(context_message_prefix):
|
|
existing_context_index = i
|
|
break
|
|
|
|
# Create the context message.
|
|
# When replacing an existing context message, reuse its ID so the
|
|
# add_messages reducer updates in-place instead of appending a
|
|
# duplicate at the end of the message list.
|
|
if existing_context_index != -1:
|
|
existing_id = getattr(messages[existing_context_index], "id", None)
|
|
context_message = SystemMessage(
|
|
content=context_message_content, id=existing_id
|
|
)
|
|
else:
|
|
context_message = SystemMessage(content=context_message_content)
|
|
|
|
if existing_context_index != -1:
|
|
# Replace existing context message
|
|
updated_messages = list(messages)
|
|
updated_messages[existing_context_index] = context_message
|
|
else:
|
|
# Insert after the first system message, or at position 0 if no system message
|
|
insert_index = first_system_index + 1 if first_system_index != -1 else 0
|
|
updated_messages = [
|
|
*messages[:insert_index],
|
|
context_message,
|
|
*messages[insert_index:],
|
|
]
|
|
|
|
return {
|
|
**state,
|
|
"messages": updated_messages,
|
|
}
|
|
|
|
async def abefore_agent(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
# Delegate to sync implementation
|
|
return self.before_agent(state, runtime)
|
|
|
|
# Intercept frontend tool calls after model returns, before ToolNode executes
|
|
def after_model(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
frontend_tools = state.get("copilotkit", {}).get("actions", [])
|
|
if not frontend_tools:
|
|
return None
|
|
|
|
frontend_tool_names = {
|
|
t.get("function", {}).get("name") or t.get("name") for t in frontend_tools
|
|
}
|
|
|
|
# Find last AI message with tool calls
|
|
messages = state.get("messages", [])
|
|
if not messages:
|
|
return None
|
|
|
|
last_message = messages[-1]
|
|
if not isinstance(last_message, AIMessage):
|
|
return None
|
|
|
|
tool_calls = getattr(last_message, "tool_calls", None) or []
|
|
if not tool_calls:
|
|
return None
|
|
|
|
backend_tool_calls = []
|
|
frontend_tool_calls = []
|
|
|
|
for call in tool_calls:
|
|
if call.get("name") in frontend_tool_names:
|
|
frontend_tool_calls.append(call)
|
|
else:
|
|
backend_tool_calls.append(call)
|
|
|
|
if not frontend_tool_calls:
|
|
return None
|
|
|
|
# Create updated AIMessage with only backend tool calls
|
|
updated_ai_message = AIMessage(
|
|
content=last_message.content,
|
|
tool_calls=backend_tool_calls,
|
|
id=last_message.id,
|
|
)
|
|
|
|
return {
|
|
"messages": [*messages[:-1], updated_ai_message],
|
|
"copilotkit": {
|
|
"intercepted_tool_calls": frontend_tool_calls,
|
|
"original_ai_message_id": last_message.id,
|
|
},
|
|
}
|
|
|
|
async def aafter_model(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
# Delegate to sync implementation
|
|
return self.after_model(state, runtime)
|
|
|
|
# Restore frontend tool calls to AIMessage before agent exits
|
|
def after_agent(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
# Drop the bridged A2UI tool for this run — all tool calls for the turn
|
|
# have executed by now; the next model call re-stashes if needed.
|
|
_a2ui_tools_by_thread.pop(_current_thread_id() or _DEFAULT_THREAD_KEY, None)
|
|
|
|
copilotkit_state = state.get("copilotkit", {})
|
|
intercepted_tool_calls = copilotkit_state.get("intercepted_tool_calls")
|
|
original_message_id = copilotkit_state.get("original_ai_message_id")
|
|
|
|
if not intercepted_tool_calls or not original_message_id:
|
|
return None
|
|
|
|
messages = state.get("messages", [])
|
|
updated_messages = []
|
|
|
|
for msg in messages:
|
|
if isinstance(msg, AIMessage) and msg.id == original_message_id:
|
|
existing_tool_calls = getattr(msg, "tool_calls", None) or []
|
|
updated_messages.append(
|
|
AIMessage(
|
|
content=msg.content,
|
|
tool_calls=[*existing_tool_calls, *intercepted_tool_calls],
|
|
id=msg.id,
|
|
)
|
|
)
|
|
else:
|
|
updated_messages.append(msg)
|
|
|
|
return {
|
|
"messages": updated_messages,
|
|
"copilotkit": {
|
|
"intercepted_tool_calls": None,
|
|
"original_ai_message_id": None,
|
|
},
|
|
}
|
|
|
|
async def aafter_agent(
|
|
self,
|
|
state: StateSchema,
|
|
runtime: Runtime[Any],
|
|
) -> dict[str, Any] | None:
|
|
# Delegate to sync implementation
|
|
return self.after_agent(state, runtime)
|