The specification of the current Veloconnect version is available online here.
The documentation refers specifically to the XML schema reference for the XML schemas to be explained.

Note:

It is technically possible to implement Veloconnect independently using the documentation - however, experience shows that this is often time-consuming and error-prone.

We therefore recommend working with experienced integration partners who can ensure a stable and future-proof implementation.

Current modules:

• Sales B2B / B2X - VC 1.6

  Optional transmission of sales data from retailers.
  Supports both traditional supplier relationships (B2B) and neutral market data recipients (B2X, e.g. ZIV MDS).

  Transmitted fields
  • Item identification (GTIN or manufacturer item number + brand)
  • Quantity sold
  • Date of sale

  Optional fields
  • Price (gross/net)
  • Postal code, sales channel
  • Serial or frame number
  • Item description, BIDEX product group, MSRP
  • Labour information (minutes, value, AW reference)

• Catalog - VC 1.5
  Structured and extended product data, including attributes, variant structures and media elements.
  Provided directly by manufacturers or via external data services (e.g., Bidex, DST, e-vendo)
   
• Stock (B2B, B2C) - VC 1.4 -
  Transmission of retailer stock levels to manufacturers, marketplaces or webshops.
  Enables availability displays such as “Available near you” and supports automated stock reconciliation
   
• Receipts - VC 1.3
  Digital transmission of
  • Order confirmations
  • Delivery notes
  • Invoices including serial numbers
     
• Core - VC 1.1
  Basic B2B functions for article and order processes
  • Master data (description, GTIN/EAN, order number, prices)
  • Availability query
  • Orders (with immediate price and quantity comparison)

• pyveloedi, Python library.
• A description of the content of the extension to V. 1.3 can be found here.