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REFERENCE

SDK Demos

How to use @asgard-js/core and @asgard-js/react, with demos you can try on the page.

Tool Calls

When an agent invokes multiple tools (database queries, external APIs) before producing its answer, the SDK automatically groups consecutive tool-call messages into a Tool Call Group. Each entry can be expanded to inspect its parameter and result.

Switch between scenarios below to see the pending, completed, and error states.

  1. Message Shape​

    Tool calls are not a template — they are a standalone ConversationMessage type:

    type ConversationToolCallMessage = {
      type: "tool-call";
      messageId: string; // `${processId}-${callSeq}`
      eventType: EventType.TOOL_CALL_START | EventType.TOOL_CALL_COMPLETE;
      processId: string;
      callSeq: number;
      toolName: string;
      reason?: string; // backend-provided call reason; the tool-call group label and consent modal title prefer reason || toolName
      toolsetName: string;
      parameter: Record<string, unknown>;
      result?: Record<string, unknown>;
      isError?: boolean; // backend-reported failure flag (0.3.x / F-009); undefined until complete
      toolUseId?: string; // this call's correlation id; an Agent tool's toolUseId becomes a subagent key (F-012)
      parentToolUseId?: string; // non-empty means this call belongs to a subagent (F-012)
      isComplete: boolean;
      time: Date;
      traceId?: string;
    };

    In real usage these messages are written into the Conversation automatically when EventType.TOOL_CALL_START / EventType.TOOL_CALL_COMPLETE events arrive — you never have to construct them by hand.

  2. State Detection​

    StateCondition
    pendingisComplete === false
    completedisComplete === true && !(isError || result?.error)
    errorisComplete === true && (isError || result?.error)
    Since 0.3.x, backend isError is the primary driver

    Failure detection now relies on the backend-reported isError flag (F-009); result.error is kept only as a legacy fallback.

  3. Built-in Tool Presentation (labels, icons, diff)​

    Since 0.3.x, the Tool Call Group synthesizes human-readable labels for built-in tools and pairs each with an identity icon (variant):

    ToolExample label
    Read / Write / EditRead {file} / Wrote {file} / Edited {file}
    SkillRan skill {skill}
    WebFetch / WebSearchFetched {host} / Searched "{query}"
    • Write / Edit also render a +/- line diff when expanded (the items[].diff field, F-007).
    • Labels, the group summary ({n} steps · …), and the expanded Initial / Result titles all follow the locale prop (en-US / ja-JP / zh-TW, F-004 / F-005 / F-008):
    <Chatbot locale="en-US" config={{ botProviderEndpoint: '...' }} customChannelId="my-channel" />

  4. Further Reading​

    For the SSE event specs behind tool calls, see the Asgard developer docs:

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