Has anyone got any resources on using Pact to test compatibility of JSON documents written and read from S3? Alongside RabbitMQ, our app shares data using various S3 buckets and we've suffered serialisation / deserialisation issues. I wondered whether Pact can be used here? I assume so, but perhaps without direct library support?

Hiya, You can use regular message pact, to test the json payloads that will be stored/read from the buckets https://docs.pact.io/getting_started/how_pact_works#non-http-testing-message-pact We have a workshop which has flavours in different examples https://docs.pact.io/university/message-pact-async/00_1_Intro You could use localstack or moto s3 or similar to mock out the bucket in test, but you can omit that by just testing the message constructor, or message consumer, agnostic of the underlying transport If you use different content-types other than json/plain text/xml, or want to test the underlying transport, there is the pact plugin framework which allows for extensibility. https://docs.pact.io/plugins/quick_start Ron created a demo of CSV content plugin, which would have been great for a client use case, where we have CSV’s files in the middle of our flow postgres db with logical replication (wal2json) -> lambda handler to transmit via kinesis firehose -> handler to transform json document and augment with additional detail -> send a csv file to a s3 bucket on a cron job, we would have BI system read the csv file from s3, and do work, publishing a processed report back to another bucket.

Oh brilliant - I thought it would be possible. I'll review that workshop. Cheers.