Dynamic inter-operability of nodes in services grids can be provided. In some cases, different version service nodes in a service grid can communicate using an inter-operability service to, for example, convert messages from one format associated with a version of a service node to another format associated with another version of a service node. Also, the message format may be converted from a current (e.g., newer) version of a node to another format which is compatible with an older version of a service node. The inter-operability service can be provided as a web service that is separate from the service nodes in the grid. The inter-operability service is associated with at least one of the service nodes in the grid and is available thereto via, for example, an administrative call by the associated service node.