AI電話エージェントをn8nで構築！Retell×n8nで電話受付を自動化

{
  "agent_id": "",
  "channel": "voice",
  "last_modification_timestamp": 1774348855656,
  "agent_name": "In bound Agent",
  "version_description": "n8n test",
  "response_engine": {
    "type": "conversation-flow",
    "version": 13,
    "conversation_flow_id": "conversation_flow_92bd3e52ce82"
  },
  "language": "ja-JP",
  "data_storage_setting": "everything",
  "opt_in_signed_url": false,
  "version": 13,
  "is_published": false,
  "post_call_analysis_model": "gpt-4.1-mini",
  "pii_config": {
    "mode": "post_call",
    "categories": []
  },
  "voice_id": "retell-Della",
  "voice_temperature": 1,
  "voice_speed": 1.2,
  "volume": 1,
  "max_call_duration_ms": 3600000,
  "interruption_sensitivity": 0.9,
  "normalize_for_speech": false,
  "allow_user_dtmf": true,
  "user_dtmf_options": {},
  "conversationFlow": {
    "conversation_flow_id": "conversation_flow_92bd3e52ce82",
    "version": 13,
    "global_prompt": " 予約が確定したら、お礼を述べて通話を終了してください。\nユーザーが「終わり」「切ります」「ありがとう」と言ったら通話を終了してください。",
    "nodes": [
      {
        "instruction": {
          "type": "prompt",
          "text": "あなたはData-Xの受付アシスタントです。お客様からの着信に対応し、無料面談の予約を受け付けます。\n\n## 動的変数\n- 顧客名: {{customer_name}}\n- 会社名: {{company_name}}\n- 備考: {{notes}}\n\n## 応答ルール\n\n### 1. 挨拶\n-「{{customer_name}}さん、お電話ありがとうございます。Data-Xでございます。」と挨拶してください。\n\n### 2. 用件の確認\n備考に「{{notes}}」と記録がありますので、その内容に触れながら用件を確認してください。\n例: 「{{company_name}}様では生成AIの導入にご関心をお持ちいただいているとうかがっております。無料面談のご予約についてでしょうか？」\n\n### 3. 無料面談の案内\n無料面談の概要を簡潔に説明してください。\n- 所要時間: 30分\n- 形式: オンライン（Zoom）\n- 内容: お客様の課題に合わせたAI導入の方向性をご提案\n\n### 4. ヒアリング\n以下の情報をお客様から聞き取ってください。\n- ご希望の日時\n- ご相談されたい内容（例: 業務の自動化、AI導入の進め方、特定のツールの選定など）\n回答があった場合は必ず復唱してください。\n\n### 5. 予約確認\n日時・相談内容がすべて揃ったら、以下の形式で読み上げて確認してください。\n「それでは、〇月〇日〇時、ご相談内容は〇〇ということで、オンライン無料面談のご予約でよろしいでしょうか？」\n\n### 6. 変更対応\nお客様が内容の変更を希望した場合は、修正内容を確認し直してください。\n\n## 注意事項\n- 丁寧語（です・ます調）で応答してください。\n- 情報が不足する場合はお客様に確認してください。推測で進めないでください。"
        },
        "name": "Welcome Node",
        "edges": [
          {
            "destination_node_id": "node-1774256583866",
            "id": "edge-1774148093768-m5o64l809",
            "transition_condition": {
              "type": "prompt",
              "prompt": "ユーザーが予約内容の復唱に対して了承し、予約が確定した"
            }
          }
        ],
        "start_speaker": "agent",
        "id": "start-node-1774147274581",
        "type": "conversation",
        "display_position": {
          "x": 558,
          "y": 6
        }
      },
      {
        "name": "End Call",
        "id": "end-call-node-1774147274581",
        "type": "end",
        "display_position": {
          "x": 2190,
          "y": 198
        },
        "instruction": {
          "type": "prompt",
          "text": "Politely end the call"
        }
      },
      {
        "instruction": {
          "type": "prompt",
          "text": "「ご予約ありがとうございます。面談のご案内を改めてお送りいたします。お電話ありがとうございました。」と締めてください。"
        },
        "name": "Closing Node",
        "edges": [],
        "id": "node-1774149010830",
        "type": "conversation",
        "display_position": {
          "x": 1662,
          "y": 198
        },
        "skip_response_edge": {
          "destination_node_id": "end-call-node-1774147274581",
          "id": "skip-response-edge-1774149347741-pggkg4kn9",
          "transition_condition": {
            "type": "prompt",
            "prompt": "Skip response"
          }
        }
      },
      {
        "tool_id": "tool-1774256469779",
        "else_edge": {
          "destination_node_id": "node-1774149010830",
          "id": "node-1774256583866-else-edge",
          "transition_condition": {
            "type": "prompt",
            "prompt": "Else"
          }
        },
        "name": "Save-reservation",
        "edges": [],
        "id": "node-1774256583866",
        "type": "function",
        "tool_type": "local",
        "speak_during_execution": false,
        "display_position": {
          "x": 1134,
          "y": 198
        },
        "wait_for_result": true
      }
    ],
    "start_node_id": "start-node-1774147274581",
    "start_speaker": "agent",
    "tools": [
      {
        "headers": {},
        "parameter_type": "json",
        "method": "POST",
        "query_params": {},
        "description": "ユーザーが予約内容（希望日時・相談内容）を確認し了承した後、予約情報をデータベースに保存する。\n",
        "type": "custom",
        "url": "https://n8n-example/webhook/retell-booking",
        "tool_id": "tool-1774256469779",
        "args_at_root": false,
        "timeout_ms": 120000,
        "speak_after_execution": true,
        "name": "Save-Reservation",
        "response_variables": {},
        "speak_during_execution": false,
        "parameters": {
          "type": "object",
          "properties": {
            "customer_name": {
              "type": "string",
              "description": "顧客の名前"
            },
            "company_name": {
              "type": "string",
              "description": "顧客の会社名"
            },
            "preferred_date": {
              "type": "string",
              "description": "希望日時（例: 3月25日 14時）"
            },
            "consultation_topic": {
              "type": "string",
              "description": "相談したい内容"
            }
          },
          "required": [
            "customer_name",
            "preferred_date",
            "consultation_topic"
          ]
        }
      }
    ],
    "model_choice": {
      "type": "cascading",
      "model": "gpt-4.1"
    },
    "tool_call_strict_mode": true,
    "knowledge_base_ids": [],
    "kb_config": {
      "top_k": 3,
      "filter_score": 0.6
    },
    "begin_tag_display_position": {
      "x": 6,
      "y": 198
    },
    "is_published": false,
    "is_transfer_cf": false
  }
}

{
  "name": "Retell Inbound Webhook - 顧客情報取得",
  "nodes": [
    {
      "parameters": {
        "httpMethod": "POST",
        "path": "retell-inbound",
        "responseMode": "responseNode",
        "options": {}
      },
      "id": "a1b2c3d4-1001-4000-a001-000000000001",
      "name": "Webhook - Inbound",
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 2,
      "position": [256, 304],
      "webhookId": "a1b2c3d4-wh01-4000-a001-000000000001"
    },
    {
      "parameters": {
        "documentId": {
          "__rl": true,
          "value": "1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s",
          "mode": "list",
          "cachedResultName": "phone_number_list",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s/edit?usp=drivesdk"
        },
        "sheetName": {
          "__rl": true,
          "value": "gid=0",
          "mode": "list",
          "cachedResultName": "シート1",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s/edit#gid=0"
        },
        "filtersUI": {
          "values": [
            {
              "lookupColumn": "user_phone_number",
              "lookupValue": "={{ $json.body.call_inbound.from_number }}"
            }
          ]
        },
        "options": {}
      },
      "id": "a1b2c3d4-1001-4000-a001-000000000002",
      "name": "Google Sheets - 顧客リスト取得",
      "type": "n8n-nodes-base.googleSheets",
      "typeVersion": 4.5,
      "position": [512, 304],
      "credentials": {
        "googleSheetsOAuth2Api": {
          "id": "fo3lC5VtAEDoLFxZ",
          "name": "Google Sheets account"
        }
      }
    },
    {
      "parameters": {
        "respondWith": "json",
        "responseBody": "={\n  \"dynamic_variables\": {\n    \"customer_name\": \"{{ $json.customer_name }}\",\n    \"company_name\": \"{{ $json.company_name }}\",\n    \"notes\": \"{{ $json.notes }}\"\n  }\n}\n",
        "options": {}
      },
      "id": "a1b2c3d4-1001-4000-a001-000000000004",
      "name": "Respond to Webhook - 顧客情報返送",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.1,
      "position": [720, 304]
    }
  ],
  "pinData": {},
  "connections": {
    "Webhook - Inbound": {
      "main": [
        [{ "node": "Google Sheets - 顧客リスト取得", "type": "main", "index": 0 }]
      ]
    },
    "Google Sheets - 顧客リスト取得": {
      "main": [
        [{ "node": "Respond to Webhook - 顧客情報返送", "type": "main", "index": 0 }]
      ]
    }
  },
  "active": false,
  "settings": {
    "executionOrder": "v1"
  }
}

Webhook - Inbound (POST /retell-inbound)
    ↓
Google Sheets - 顧客リスト取得 (filtersUIで電話番号照合)
    ↓
Respond to Webhook - 顧客情報返送 (JSON)

{
  "dynamic_variables": {
    "customer_name": "{{ $json.customer_name }}",
    "company_name": "{{ $json.company_name }}",
    "notes": "{{ $json.notes }}"
  }
}

{
  "name": "Retell Custom Function - 予約処理",
  "nodes": [
    {
      "parameters": {
        "httpMethod": "POST",
        "path": "retell-booking",
        "responseMode": "responseNode",
        "options": {}
      },
      "id": "b2c3d4e5-2001-4000-b001-000000000001",
      "name": "Webhook - Custom Function",
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 2,
      "position": [-128, 304],
      "webhookId": "b2c3d4e5-wh02-4000-b001-000000000001"
    },
    {
      "parameters": {
        "operation": "appendOrUpdate",
        "documentId": {
          "__rl": true,
          "value": "1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s",
          "mode": "list",
          "cachedResultName": "phone_number_list",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s/edit?usp=drivesdk"
        },
        "sheetName": {
          "__rl": true,
          "value": "gid=0",
          "mode": "list",
          "cachedResultName": "シート1",
          "cachedResultUrl": "https://docs.google.com/spreadsheets/d/1doPBvAbJoiOqEitrD5aMgbpOL7kLwGxuX6nYqaLon1s/edit#gid=0"
        },
        "columns": {
          "mappingMode": "defineBelow",
          "value": {
            "Reservation Date": "={{ $json.body.args.preferred_date }}",
            "Consultation Content": "={{ $json.body.args.consultation_topic }}",
            "user_phone_number": "={{ $json.body.call.from_number }}"
          },
          "matchingColumns": ["user_phone_number"],
          "schema": [
            {
              "id": "user_phone_number",
              "displayName": "user_phone_number",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": false
            },
            {
              "id": "customer_name",
              "displayName": "customer_name",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": true
            },
            {
              "id": "company_name",
              "displayName": "company_name",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": true
            },
            {
              "id": "last_contact_date",
              "displayName": "last_contact_date",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": true
            },
            {
              "id": "notes",
              "displayName": "notes",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true,
              "removed": true
            },
            {
              "id": "Reservation Date",
              "displayName": "Reservation Date",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true
            },
            {
              "id": "Consultation Content",
              "displayName": "Consultation Content",
              "required": false,
              "defaultMatch": false,
              "display": true,
              "type": "string",
              "canBeUsedToMatch": true
            }
          ],
          "attemptToConvertTypes": false,
          "convertFieldsToString": false
        },
        "options": {}
      },
      "id": "b2c3d4e5-2001-4000-b001-000000000002",
      "name": "Google Sheets - 予約情報保存",
      "type": "n8n-nodes-base.googleSheets",
      "typeVersion": 4.5,
      "position": [304, 304],
      "credentials": {
        "googleSheetsOAuth2Api": {
          "id": "fo3lC5VtAEDoLFxZ",
          "name": "Google Sheets account"
        }
      }
    },
    {
      "parameters": {
        "respondWith": "json",
        "responseBody": "={{ JSON.stringify({ booking_confirmed: true, message: \"予約が確定しました\" }) }}",
        "options": {}
      },
      "id": "b2c3d4e5-2001-4000-b001-000000000006",
      "name": "Respond to Webhook - 予約確定返送",
      "type": "n8n-nodes-base.respondToWebhook",
      "typeVersion": 1.1,
      "position": [704, 304]
    },
    {
      "parameters": {
        "select": "channel",
        "channelId": {
          "__rl": true,
          "value": "C09G8RU6RPC",
          "mode": "list",
          "cachedResultName": "n8n-test"
        },
        "text": "新規予約が入りました",
        "otherOptions": {}
      },
      "id": "b2c3d4e5-2001-4000-b001-000000000005",
      "name": "Slack - 予約通知",
      "type": "n8n-nodes-base.slack",
      "typeVersion": 2.2,
      "position": [928, 304],
      "credentials": {
        "slackApi": {
          "id": "KyHQfIGnYhJNhWhg",
          "name": "Slack account"
        }
      }
    }
  ],
  "pinData": {},
  "connections": {
    "Webhook - Custom Function": {
      "main": [
        [{ "node": "Google Sheets - 予約情報保存", "type": "main", "index": 0 }]
      ]
    },
    "Google Sheets - 予約情報保存": {
      "main": [
        [{ "node": "Respond to Webhook - 予約確定返送", "type": "main", "index": 0 }]
      ]
    },
    "Respond to Webhook - 予約確定返送": {
      "main": [
        [{ "node": "Slack - 予約通知", "type": "main", "index": 0 }]
      ]
    }
  },
  "active": false,
  "settings": {
    "executionOrder": "v1"
  }
}

Webhook - Custom Function (POST /retell-booking)
    ↓
Google Sheets - 予約情報保存 (Append or Update)
    ↓
Respond to Webhook - 予約確定返送 (JSON)
    ↓
Slack - 予約通知

{{ JSON.stringify({ booking_confirmed: true, message: "予約が確定しました" }) }}