Workflow Overview

The Order-to-Cash flow involves four key transaction types:

┌─────────────┐     ┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   850 PO    │────▶│   855 POA   │────▶│   856 ASN   │────▶│ 810 Invoice │
│ (Retailer)  │     │ (Supplier)  │     │ (Supplier)  │     │ (Supplier)  │
└─────────────┘     └─────────────┘     └─────────────┘     └─────────────┘
     │                    │                    │                    │
     │                    │                    │                    │
   Buyer              Confirm              Ship goods            Bill for
  places              receipt &            & notify               goods
   order              acceptance                                 shipped

Step	Transaction	Direction	Purpose
1	850 Purchase Order	Inbound	Retailer orders products
2	855 PO Acknowledgment	Outbound	You confirm/modify the order
3	856 Advance Ship Notice	Outbound	You notify shipment details
4	810 Invoice	Outbound	You bill for shipped goods

Step 1: Receive the Purchase Order (850)

Detect New Orders

Using the Inbox (v4):

curl -X GET "https://api.orderful.com/v4/inbox?transactionType=850" \
  -H "orderful-api-key: YOUR_API_KEY" \
  -H "orderful-version: v4"

Using Polling (v3):

curl -X GET "https://api.orderful.com/v3/transactions?direction=inbound&transactionType=850&deliveryState=pending" \
  -H "orderful-api-key: YOUR_API_KEY"

Get the Full PO Content

curl -X GET "https://api.orderful.com/v3/transactions/12345/message" \
  -H "orderful-api-key: YOUR_API_KEY"

Example Response:

{
  "purpose": "original",
  "purchaseOrderType": "standalone",
  "purchaseOrderNumber": "PO-2024-001234",
  "purchaseOrderDate": "2024-01-15",
  "releaseNumber": "REL-001",
  "contractNumber": "CNT-2024-ABC",
  "acknowledgmentType": "withDetail",
  "conditionsAndRestrictions": [
    {
      "conditionType": "shipComplete",
      "action": "confirm",
      "services": "twoDayService",
      "maxOrderValue": "50000.00"
    }
  ],
  "parties": {
    "buyer": {
      "name": "Acme Corporation",
      "additionalName1": "Procurement Department",
      "identificationCode": "123456789",
      "identificationCodeType": "duns",
      "addressLine1": "123 Main Street",
      "addressLine2": "Suite 500",
      "city": "Chicago",
      "stateOrProvinceCode": "IL",
      "postalCode": "60601",
      "countryCode": "US",
      "zoneType": "commercial",
      "contacts": [
        {
          "type": "primary",
          "name": "John Smith",
          "phoneNumber": "312-555-0100",
          "email": "john.smith@acme.com"
        },
        {
          "type": "orderInquiry",
          "name": "Order Desk",
          "phoneNumber": "312-555-0200",
          "email": "orders@acme.com"
        }
      ]
    },
    "shipTo": {
      "name": "Acme Corporation - Warehouse",
      "identificationCode": "987654321",
      "identificationCodeType": "duns",
      "addressLine1": "456 Warehouse Boulevard",
      "city": "Elk Grove Village",
      "stateOrProvinceCode": "IL",
      "postalCode": "60007",
      "countryCode": "US",
      "zoneType": "commercial",
      "contacts": [
        {
          "type": "receiving",
          "name": "Receiving Department",
          "phoneNumber": "847-555-0300"
        }
      ]
    },
    "billTo": {
      "name": "Acme Corporation",
      "identificationCode": "123456789",
      "identificationCodeType": "duns",
      "addressLine1": "123 Main Street",
      "addressLine2": "Accounts Payable",
      "city": "Chicago",
      "stateOrProvinceCode": "IL",
      "postalCode": "60601",
      "countryCode": "US"
    },
    "shipFrom": {
      "name": "Global Suppliers Inc.",
      "identificationCode": "555123456",
      "identificationCodeType": "duns",
      "addressLine1": "789 Manufacturing Drive",
      "city": "Dallas",
      "stateOrProvinceCode": "TX",
      "postalCode": "75201",
      "countryCode": "US"
    },
    "accountsPayable": {
      "name": "Acme Corporation - AP",
      "addressLine1": "123 Main Street",
      "addressLine2": "Finance Department",
      "city": "Chicago",
      "stateOrProvinceCode": "IL",
      "postalCode": "60601",
      "countryCode": "US"
    },
    "soldTo": {
      "name": "Acme Corporation",
      "identificationCode": "123456789",
      "identificationCodeType": "duns",
      "addressLine1": "123 Main Street",
      "city": "Chicago",
      "stateOrProvinceCode": "IL",
      "postalCode": "60601",
      "countryCode": "US"
    },
    "supplier": {
      "name": "Global Suppliers Inc.",
      "additionalName1": "Sales Division",
      "identificationCode": "555123456",
      "identificationCodeType": "duns",
      "addressLine1": "789 Manufacturing Drive",
      "city": "Dallas",
      "stateOrProvinceCode": "TX",
      "postalCode": "75201",
      "countryCode": "US",
      "zoneType": "commercial",
      "contacts": [
        {
          "type": "primary",
          "name": "Sarah Johnson",
          "phoneNumber": "214-555-0400",
          "email": "sarah.johnson@globalsuppliers.com"
        }
      ]
    }
  },
  "buyersCurrency": {
    "currencyCode": "USD",
    "exchangeRate": "1.00"
  },
  "sellersCurrency": {
    "currencyCode": "USD",
    "exchangeRate": "1.00"
  },
  "notes": {
    "general": {
      "description": "General order notes",
      "text": [
        "Please ensure all items are properly packaged",
        "Include packing slip with shipment"
      ]
    },
    "orderInstructions": {
      "description": "Order specific instructions",
      "text": [
        "All items must be shipped together",
        "Use standard carrier for delivery"
      ]
    },
    "shippingInstructions": {
      "description": "Shipping instructions",
      "text": [
        "Deliver during business hours only",
        "Contact receiving department 24 hours before delivery"
      ]
    }
  },
  "paperwork": [
    {
      "reportType": "materialDataSheet",
      "reportTransmissionType": "withShipmentPackage",
      "copiesNeeded": 2,
      "isoLanguageCode": "en",
      "description": "Material safety data sheets required"
    },
    {
      "reportType": "technicalInformation",
      "url": "https://example.com/tech-specs",
      "description": "Technical specifications available online"
    }
  ],
  "packaging": [
    {
      "characteristicType": "palletType",
      "description": "Standard 48x40 pallets required",
      "unitLoadOption": "palletized"
    },
    {
      "characteristicType": "shippingPackageLabeling",
      "description": "Include PO number on all labels",
      "agencyType": "uniformCodeCouncil"
    }
  ],
  "termsOfSale": {
    "type": "basicDiscountOffered",
    "basisDate": "invoiceDate",
    "discountPercent": "2.0",
    "discountDaysDue": 10,
    "discountDueDate": "2024-02-25",
    "netDaysDue": 30,
    "netDueDate": "2024-02-15",
    "discountAmount": "200.00",
    "description": "2/10 Net 30 payment terms",
    "paymentMethodType": "check"
  },
  "references": {
    "accountNumber": {
      "value": "ACC-12345",
      "description": "Buyer account number"
    },
    "customerOrderNumber": {
      "value": "CUST-ORD-789",
      "description": "Customer order reference"
    },
    "vendorNumber": {
      "value": "VND-456",
      "description": "Vendor number"
    },
    "departmentNumber": {
      "value": "DEPT-10",
      "description": "Department code"
    },
    "storeNumber": {
      "value": "STORE-001",
      "description": "Store location"
    },
    "promotionNumber": {
      "value": "PROMO-2024-Q1",
      "description": "Promotion identifier"
    }
  },
  "dates": {
    "purchaseOrderDate": "2024-01-15",
    "requestedShipDate": "2024-02-01",
    "requestedDeliveryDate": "2024-02-05",
    "earliestShipDate": "2024-01-28",
    "latestShipDate": "2024-02-05",
    "earliestDeliveryDate": "2024-02-01",
    "latestDeliveryDate": "2024-02-10",
    "cancelAfterDate": "2024-02-15",
    "customerOrderDate": "2024-01-10"
  },
  "carrierDetails": {
    "routing": [
      {
        "sequenceType": "origin",
        "standardCarrierAlphaCode": "FEDX",
        "transportationMethod": "commonCarrier",
        "locationType": "origin",
        "location": "Dallas, TX",
        "serviceLevel": "ground",
        "transitDirectionType": "sellerToBuyer",
        "transitTimeType": "workingDays",
        "transitTime": "3"
      }
    ],
    "freeOnBoard": [
      {
        "methodOfPayment": "prepaidBySeller",
        "locationType": "origin",
        "locationDescription": "Dallas, TX",
        "titlePassageType": "origin",
        "titlePassageDescription": "Dallas, TX",
        "transportationTermsSource": "tradeTerms",
        "transportationTerms": "freeOnBoard",
        "riskOfLoss": "toDestinationBuyer"
      }
    ],
    "specialHandling": [
      {
        "handlingType": "fragile",
        "description": "Handle with care"
      },
      {
        "handlingType": "temperatureControl",
        "description": "Maintain temperature between 60-70°F"
      }
    ]
  },
  "allowances": [
    {
      "type": "volume",
      "amount": "500.00",
      "percent": "5.0",
      "percentBasis": "basePrice",
      "methodOfHandling": "paidByVendor",
      "description": "Volume discount for orders over $10,000"
    }
  ],
  "charges": [
    {
      "type": "freight",
      "amount": "250.00",
      "methodOfHandling": "prepaid",
      "description": "Prepaid freight charges"
    }
  ],
  "monetaryAmounts": {
    "gross": "10500.00",
    "net": "10000.00"
  },
  "taxes": {
    "stateProvincialTax": {
      "amount": "650.00",
      "percent": "6.5",
      "jurisdictionType": "state",
      "jurisdictionCode": "IL"
    },
    "localTax": {
      "amount": "100.00",
      "percent": "1.0",
      "jurisdictionType": "local",
      "jurisdictionCode": "CHI"
    }
  },
  "lineItems": [
    {
      "purchaseOrderLineId": "1",
      "quantity": {
        "value": "100",
        "unitOfMeasure": "each"
      },
      "unitCostPrice": "45.00",
      "unitPriceBasis": "perEach",
      "additionalPricing": [
        {
          "priceType": "promotional",
          "unitPrice": "42.00",
          "unitPriceBasis": "perEach",
          "quantityPerUnitPrice": "1"
        }
      ],
      "productIds": {
        "buyerItemNumber": "ACME-12345",
        "vendorItemNumber": "GSI-78901",
        "gtin13": "1234567890123",
        "buyerItemIds": [
          {
            "type": "sku",
            "value": "SKU-ACME-12345"
          }
        ]
      },
      "productAttributes": {
        "description": "Premium Widget - Blue",
        "colorCode": "BLU",
        "colorDescription": "Blue",
        "sizeCode": "LG",
        "sizeDescription": "Large",
        "materialCode": "STEEL",
        "materialDescription": "Stainless Steel"
      },
      "outerPack": {
        "numberOfUnits": "10",
        "size": "12",
        "sizeUOM": "each",
        "packageForm": "box",
        "packageMaterial": "corrugated",
        "weightUOM": "pound",
        "grossWeight": "50",
        "netWeight": "45",
        "dimensionUOM": "inch",
        "length": "24",
        "width": "18",
        "height": "12",
        "packageId": "PKG-001"
      },
      "innerPack": {
        "numberOfUnits": "1",
        "size": "1",
        "sizeUOM": "each",
        "packageForm": "box",
        "packageMaterial": "corrugated",
        "weightUOM": "pound",
        "grossWeight": "5",
        "netWeight": "4.5"
      },
      "packaging": [
        {
          "characteristicType": "typeOfPackage",
          "description": "Corrugated cardboard box",
          "unitLoadOption": "palletized"
        }
      ],
      "dates": {
        "requestedShipDate": "2024-02-01",
        "requestedDeliveryDate": "2024-02-05",
        "earliestShipDate": "2024-01-28"
      },
      "references": {
        "departmentNumber": {
          "value": "DEPT-10",
          "description": "Department"
        },
        "storeNumber": {
          "value": "STORE-001",
          "description": "Store location"
        }
      },
      "destinationQuantities": {
        "locationType": "warehouse",
        "unitOfMeasure": "each",
        "quantityByLocation": [
          {
            "destinationId": "WH-001",
            "quantity": "60"
          },
          {
            "destinationId": "WH-002",
            "quantity": "40"
          }
        ]
      },
      "allowances": [
        {
          "type": "quantityDiscount",
          "amount": "50.00",
          "percent": "1.0",
          "methodOfHandling": "paidByVendor",
          "description": "Quantity discount for 100+ units"
        }
      ],
      "charges": [
        {
          "type": "handling",
          "amount": "25.00",
          "methodOfHandling": "prepaid",
          "description": "Special handling charge"
        }
      ],
      "monetaryAmounts": {
        "gross": "4500.00",
        "net": "4450.00"
      },
      "sublineItems": [
        {
          "sublineId": "1-1",
          "quantity": {
            "value": "50",
            "unitOfMeasure": "each"
          },
          "productIds": {
            "buyerItemNumber": "ACME-12345-A",
            "vendorItemNumber": "GSI-78901-A"
          },
          "unitCostPrice": "45.00",
          "unitPriceBasis": "perEach"
        }
      ],
      "notes": {
        "general": {
          "description": "Line item notes",
          "text": [
            "Ensure proper packaging",
            "Include installation instructions"
          ]
        },
        "shippingInstructions": {
          "description": "Shipping notes",
          "text": [
            "Ship in original packaging",
            "Do not stack more than 5 high"
          ]
        }
      },
      "paperwork": [
        {
          "reportType": "materialDataSheet",
          "copiesNeeded": 1,
          "description": "MSDS required for this item"
        }
      ],
      "conditionsAndRestrictions": [
        {
          "conditionType": "shipComplete",
          "action": "confirm"
        }
      ],
      "carrierDetails": {
        "routing": [
          {
            "sequenceType": "origin",
            "transportationMethod": "commonCarrier",
            "serviceLevel": "ground"
          }
        ],
        "freeOnBoard": [
          {
            "methodOfPayment": "prepaidBySeller",
            "locationType": "origin"
          }
        ]
      }
    },
    {
      "purchaseOrderLineId": "2",
      "quantity": {
        "value": "250",
        "unitOfMeasure": "case"
      },
      "unitCostPrice": "18.50",
      "unitPriceBasis": "perEach",
      "productIds": {
        "buyerItemNumber": "ACME-67890",
        "vendorItemNumber": "GSI-23456",
        "gtin14": "12345678901234"
      },
      "productAttributes": {
        "description": "Standard Widget - Red",
        "colorCode": "RED",
        "colorDescription": "Red",
        "sizeCode": "MD",
        "sizeDescription": "Medium"
      },
      "outerPack": {
        "numberOfUnits": "25",
        "size": "1",
        "sizeUOM": "case",
        "packageForm": "box",
        "packageMaterial": "corrugated",
        "weightUOM": "pound",
        "grossWeight": "30",
        "netWeight": "28"
      },
      "dates": {
        "requestedShipDate": "2024-02-01",
        "requestedDeliveryDate": "2024-02-05"
      },
      "monetaryAmounts": {
        "gross": "4625.00",
        "net": "4625.00"
      },
      "notes": {
        "general": {
          "description": "Standard item",
          "text": [
            "Standard packaging acceptable"
          ]
        }
      }
    },
    {
      "purchaseOrderLineId": "3",
      "quantity": {
        "value": "50",
        "unitOfMeasure": "each"
      },
      "unitCostPrice": "17.50",
      "productIds": {
        "buyerItemNumber": "ACME-11111",
        "vendorItemNumber": "GSI-33333",
        "gtin12": "123456789012"
      },
      "monetaryAmounts": {
        "gross": "875.00",
        "net": "875.00"
      }
    }
  ]
}

Process in Your System

Parse the PO data
Check inventory availability
Validate pricing
Create a sales order in your ERP/OMS

Confirm Receipt

After successful processing, acknowledge the delivery:

curl -X POST "https://api.orderful.com/v4/transactions/12345/deliveries/67890/approve" \
  -H "orderful-api-key: YOUR_API_KEY" \
  -H "orderful-version: v4"

Step 2: Send Purchase Order Acknowledgment (855)

The POA tells the retailer whether you can fulfill the order. Send it within the timeframe specified in your trading partner agreement (typically 24-48 hours).

Acknowledgment Scenarios

Scenario	Code	Description
Full acceptance	`AC` + all lines `IA`	Accept order as-is
Partial acceptance	`AC` + mixed codes	Some items accepted, others modified
Changes made	`AC` + lines with `IC`	Accepted with changes (qty, date, etc.)
Rejection	`RJ`	Entire order rejected

Example: Full Acceptance

curl -X POST "https://api.orderful.com/v4/transactions" \
  -H "orderful-api-key: YOUR_API_KEY" \
  -H "orderful-version: v4" \
  -H "Content-Type: application/json" \
  -d '{
    "sender": { "isaId": "YOUR_ISA_ID" },
    "receiver": { "isaId": "RETAILCORP" },
    "stream": "live",
    "transactionType": "855",
    "relatedTransactionId": 12345,
    "message": {
      "purchaseOrderAcknowledgment": {
        "acknowledgmentType": "AC",
        "purchaseOrderNumber": "PO-2026-78901",
        "acknowledgedDate": "2026-01-15",
        "estimatedShipDate": "2026-01-25",
        "lineItems": [
          {
            "lineNumber": "001",
            "acknowledgmentCode": "IA",
            "vendorPartNumber": "WIDGET-A",
            "acknowledgedQuantity": 500,
            "unitPrice": 12.50
          },
          {
            "lineNumber": "002",
            "acknowledgmentCode": "IA",
            "vendorPartNumber": "WIDGET-B",
            "acknowledgedQuantity": 300,
            "unitPrice": 12.50
          }
        ]
      }
    }
  }'

Example: Partial Acceptance (Backorder)

{
  "message": {
    "purchaseOrderAcknowledgment": {
      "acknowledgmentType": "AC",
      "purchaseOrderNumber": "PO-2026-78901",
      "lineItems": [
        {
          "lineNumber": "001",
          "acknowledgmentCode": "IA",
          "acknowledgedQuantity": 500
        },
        {
          "lineNumber": "002",
          "acknowledgmentCode": "IB",
          "acknowledgedQuantity": 200,
          "backorderQuantity": 100,
          "estimatedBackorderDate": "2026-02-15",
          "note": "100 units on backorder, shipping 200 now"
        }
      ]
    }
  }
}

Step 3: Send Advance Ship Notice (856)

When you ship the order, send an ASN with carton-level detail. This enables the retailer to receive goods efficiently.

ASN Structure

Shipment (856)
├── Shipment Header (carrier, dates, totals)
├── Order Reference (PO number)
└── Hierarchical Levels
    ├── Shipment Level (HL-S)
    │   └── Order Level (HL-O)
    │       └── Pack Level (HL-P) - Cartons/Pallets
    │           └── Item Level (HL-I) - Line items

Example: Complete ASN

curl -X POST "https://api.orderful.com/v4/transactions" \
  -H "orderful-api-key: YOUR_API_KEY" \
  -H "orderful-version: v4" \
  -H "Content-Type: application/json" \
  -d '{
    "sender": { "isaId": "YOUR_ISA_ID" },
    "receiver": { "isaId": "RETAILCORP" },
    "stream": "live",
    "transactionType": "856",
    "relatedTransactionId": 12345,
    "message": {
      "shipNotice": {
        "shipmentIdentifier": "SHIP-2026-001234",
        "shipDate": "2026-01-25",
        "estimatedDeliveryDate": "2026-01-28",
        "shipmentWeight": 125.5,
        "weightUnit": "LB",
        "carrier": {
          "name": "FastFreight Logistics",
          "scac": "FFRL",
          "serviceLevel": "GROUND",
          "proNumber": "PRO123456789",
          "trackingNumbers": ["1Z999AA10123456784"]
        },
        "shipFrom": {
          "name": "Your Company Warehouse",
          "address": {
            "street": "100 Industrial Way",
            "city": "Manufacturing City",
            "state": "TX",
            "postalCode": "75001"
          }
        },
        "shipTo": {
          "locationCode": "DC-005",
          "name": "Retail Corp DC #5",
          "address": {
            "street": "456 Warehouse Blvd",
            "city": "Commerce City",
            "state": "CA",
            "postalCode": "90211"
          }
        },
        "purchaseOrderNumber": "PO-2026-78901",
        "packages": [
          {
            "packageType": "CTN",
            "packageId": "SSCC00123456789012345671",
            "weight": 65.5,
            "weightUnit": "LB",
            "contents": [
              {
                "lineNumber": "001",
                "vendorPartNumber": "WIDGET-A",
                "upc": "012345678901",
                "quantity": 500
              }
            ]
          },
          {
            "packageType": "CTN",
            "packageId": "SSCC00123456789012345672",
            "weight": 60.0,
            "weightUnit": "LB",
            "contents": [
              {
                "lineNumber": "002",
                "vendorPartNumber": "WIDGET-B",
                "upc": "012345678902",
                "quantity": 300
              }
            ]
          }
        ]
      }
    }
  }'

GS1-128 Labels

Most retailers require GS1-128 (UCC-128) labels on each carton. The SSCC (Serial Shipping Container Code) in the ASN must match the barcode on the physical carton.

Step 4: Send Invoice (810)

After shipment, send the invoice. Many retailers have strict timing requirements (e.g., invoice within 48 hours of ship date).

Example: Complete Invoice

curl -X POST "https://api.orderful.com/v4/transactions" \
  -H "orderful-api-key: YOUR_API_KEY" \
  -H "orderful-version: v4" \
  -H "Content-Type: application/json" \
  -d '{
    "sender": { "isaId": "YOUR_ISA_ID" },
    "receiver": { "isaId": "RETAILCORP" },
    "stream": "live",
    "transactionType": "810",
    "relatedTransactionId": 12345,
    "message": {
      "invoice": {
        "invoiceNumber": "INV-2026-001234",
        "invoiceDate": "2026-01-25",
        "invoiceType": "original",
        "purchaseOrderNumber": "PO-2026-78901",
        "shipDate": "2026-01-25",
        "paymentTerms": {
          "termsType": "NET",
          "netDays": 30,
          "discountPercent": 2,
          "discountDays": 10,
          "description": "2% 10 Net 30"
        },
        "remitTo": {
          "name": "Your Company Inc",
          "address": {
            "street": "100 Corporate Drive",
            "city": "Business City",
            "state": "CA",
            "postalCode": "90001"
          }
        },
        "lineItems": [
          {
            "lineNumber": "001",
            "vendorPartNumber": "WIDGET-A",
            "upc": "012345678901",
            "description": "Premium Widget - Blue",
            "quantity": 500,
            "unitOfMeasure": "EA",
            "unitPrice": 12.50,
            "lineTotal": 6250.00
          },
          {
            "lineNumber": "002",
            "vendorPartNumber": "WIDGET-B",
            "upc": "012345678902",
            "description": "Premium Widget - Red",
            "quantity": 300,
            "unitOfMeasure": "EA",
            "unitPrice": 12.50,
            "lineTotal": 3750.00
          }
        ],
        "summary": {
          "totalLineItems": 2,
          "totalQuantity": 800,
          "subtotal": 10000.00,
          "freightAmount": 150.00,
          "taxAmount": 0.00,
          "totalAmount": 10150.00
        }
      }
    }
  }'

Handling Exceptions

Scenario: Partial Shipment

If you can't ship everything at once:

855 POA: Indicate partial acceptance or backorder
856 ASN: Send for items being shipped now
810 Invoice: Invoice only for shipped items
Repeat 3-4: Send additional ASN/Invoice when backorder ships

Scenario: Order Changes

If the retailer sends an order change (860):

Receive and process the 860
Send an 865 (PO Change Acknowledgment)
Adjust your fulfillment accordingly

Scenario: Returns

For return authorizations, implement the 180/944 or 180/812 flow as required by your trading partner.

Timeline Best Practices

Event	Recommended Timing
855 POA	Within 24 hours of receiving 850
856 ASN	Same day as shipment (before goods arrive)
810 Invoice	Within 48 hours of shipment

⚠️
Note: Timing requirements vary by trading partner. Check your specific partner's guidelines.

Monitoring Your Integration

Check Transaction Status

curl -X GET "https://api.orderful.com/v3/transactions/12345" \
  -H "orderful-api-key: YOUR_API_KEY"

View in Orderful Portal

Monitor your transactions in real-time:

Go to Transactions in the Orderful portal
Filter by transaction type, date, or status
Click any transaction to see full details

Next Steps

Testing Guide - Test your O2C flow end-to-end
Webhook Configuration - Set up real-time notifications
Error Handling - Handle edge cases gracefully
Going Live Checklist - Production readiness checklist