MIB Smithy SDK is a dynamic extension to Tcl/Tk (8.1+) that allows development of custom scripts for controlling SNMP agents, manipulating SMI definitions, doing conversions, and more. It is based on the core of Muonics' MIB Smithy, and the SDK supports SMIv1 and SMIv2, as well as SNMPv1/v2c/v3 with HMAC-SHA-96 and HMAC-MD5-96 authentication and CBC-DES privacy. It also provides complete read-write access to all elements of SMI/MIB Module definitions, unlike similar extensions that provide only read access to a limited subset. The SDK allows multiple discrete SMI databases and SNMP sessions, and provides all of the built-in validation and error recovery capabilites of the full product, without the visual MIB development environment.