feat(agents): add support for remote agents (#16013)

2026-04-21 02:24:09 -07:00 · 2026-01-06 18:45:05 -05:00
parent 1e31427da8
commit 96b9be3ec4
8 changed files with 980 additions and 41 deletions
@@ -0,0 +1,142 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type {
+  Message,
+  Task,
+  Part,
+  TextPart,
+  DataPart,
+  FilePart,
+} from '@a2a-js/sdk';
+
+/**
+ * Extracts a human-readable text representation from a Message object.
+ * Handles Text, Data (JSON), and File parts.
+ */
+export function extractMessageText(message: Message | undefined): string {
+  if (!message || !message.parts) {
+    return '';
+  }
+
+  const parts = message.parts
+    .map((part) => extractPartText(part))
+    .filter(Boolean);
+  return parts.join('\n');
+}
+
+/**
+ * Extracts text from a single Part.
+ */
+export function extractPartText(part: Part): string {
+  if (isTextPart(part)) {
+    return part.text;
+  }
+
+  if (isDataPart(part)) {
+    // Attempt to format known data types if metadata exists, otherwise JSON stringify
+    return `Data: ${JSON.stringify(part.data)}`;
+  }
+
+  if (isFilePart(part)) {
+    const fileData = part.file;
+    if (fileData.name) {
+      return `File: ${fileData.name}`;
+    }
+    if ('uri' in fileData && fileData.uri) {
+      return `File: ${fileData.uri}`;
+    }
+    return `File: [binary/unnamed]`;
+  }
+
+  return '';
+}
+
+/**
+ * Extracts a human-readable text summary from a Task object.
+ * Includes status, ID, and any artifact content.
+ */
+export function extractTaskText(task: Task): string {
+  let output = `ID: ${task.id}\n`;
+  output += `State: ${task.status.state}\n`;
+
+  // Status Message
+  const statusMessageText = extractMessageText(task.status.message);
+  if (statusMessageText) {
+    output += `Status Message: ${statusMessageText}\n`;
+  }
+
+  // Artifacts
+  if (task.artifacts && task.artifacts.length > 0) {
+    output += `Artifacts:\n`;
+    for (const artifact of task.artifacts) {
+      output += `  - Name: ${artifact.name}\n`;
+      if (artifact.parts && artifact.parts.length > 0) {
+        // Treat artifact parts as a message for extraction
+        const artifactContent = artifact.parts
+          .map((p) => extractPartText(p))
+          .filter(Boolean)
+          .join('\n');
+
+        if (artifactContent) {
+          // Indent content for readability
+          const indentedContent = artifactContent.replace(/^/gm, '    ');
+          output += `    Content:\n${indentedContent}\n`;
+        }
+      }
+    }
+  }
+
+  return output;
+}
+
+// Type Guards
+
+function isTextPart(part: Part): part is TextPart {
+  return part.kind === 'text';
+}
+
+function isDataPart(part: Part): part is DataPart {
+  return part.kind === 'data';
+}
+
+function isFilePart(part: Part): part is FilePart {
+  return part.kind === 'file';
+}
+
+/**
+ * Extracts contextId and taskId from a Message or Task response.
+ * Follows the pattern from the A2A CLI sample to maintain conversational continuity.
+ */
+export function extractIdsFromResponse(result: Message | Task): {
+  contextId?: string;
+  taskId?: string;
+} {
+  let contextId: string | undefined;
+  let taskId: string | undefined;
+
+  if (result.kind === 'message') {
+    taskId = result.taskId;
+    contextId = result.contextId;
+  } else if (result.kind === 'task') {
+    taskId = result.id;
+    contextId = result.contextId;
+
+    // If the task is in a final state (and not input-required), we clear the taskId
+    // so that the next interaction starts a fresh task (or keeps context without being bound to the old task).
+    if (
+      result.status &&
+      result.status.state !== 'input-required' &&
+      (result.status.state === 'completed' ||
+        result.status.state === 'failed' ||
+        result.status.state === 'canceled')
+    ) {
+      taskId = undefined;
+    }
+  }
+
+  return { contextId, taskId };
+}