Decode Filecoin message parameters against the recipient actor
A method number can have different meanings on different Filecoin actors. A support trace needs the recipient address, method and CBOR payload from the same message.
Preserve message context
Replace all example values with the message's To, numeric Method and base64 Params. For an old message, replace the empty tipset key with the appropriate historical state anchor so the decoder resolves the correct recipient code.
{"jsonrpc":"2.0","id":1,"method":"Filecoin.StateDecodeParams","params":["f01234",2,"<base64 CBOR parameters>",[]]}
Separate decoded intent from outcome
Read the returned JSON with the actor-specific schema. For example, an amount inside decoded method parameters is distinct from the message's outer Value. Decoding does not execute the message. Match the message CID to its execution receipt to determine whether the requested change actually succeeded.