# Proof of Acceptance > The payee needs proof that at the time of each transaction, the majority of nodes agreed it was the first received. > > \- Satoshi Nakamoto, Bitcoin Whitepaper ![](/files/6ItrlN6j8MftjxZe2JSB) For merchants to have confidence in funds received via the Bitcoin network, there must be a means for them to be able to query the nodes who validate the transaction to ensure that it is not double spending valid inputs. This can be achieved in a variety of ways including: * Querying a selection of nodes for a transaction output that meets the merchant’s requirements * By the merchant sending the transaction on the sender’s behalf, and receiving notification of the transaction’s validity from the nodes it uses * Through double-spend alarm systems that notify any parties to transactions that double spend an input Without these systems, it becomes much harder for merchants to accept Bitcoin payments for goods or services without waiting for them to be confirmed in a valid block secured by proof of work. Learn more about the First seen rule here: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://hub.bsvblockchain.org/higher-learning/bsv-academy/bsv-theory/transactions/proof-of-acceptance.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.