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I want to have two different contracts that have functions that should interact with each other. Is there a way to pass/return values through function call between contracts?

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Contracts don't currently return any data. You should use callbacks for on-chain data transmission, or use an off-chain oracle.

On chain, you use the TRANSFER_TOKENS; instruction to send from contract a to contract b. Contract b would then send data back via another TRANSFER_TOKEN; call. You should update the storage of contract a to acknowledge that a call back is imminent.

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    That’s the theory. In practice, it’s almost impossible to write it, because of the type system. B has to know the type of A, so either you have to deploy both contracts, or you have to originate an intermediary contract C that knows A and has a type compatible with B. We will post a blog post on that soon.
    – lefessan
    Feb 14 '19 at 8:47
  • Yeah, we're developing a framework to help with this. Feb 14 '19 at 9:03
  • At some point, Liquidity will have native support for that too.
    – lefessan
    Feb 14 '19 at 9:21
  • @FLFOCP perhaps write this as a separate answer ?
    – Ezy
    Feb 14 '19 at 10:47
  • The answer to the problems mentioned above are entrypoints, which are described in more detail in this blog post: blog.nomadic-labs.com/category/…
    – arvidj
    Dec 3 '19 at 13:53

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