The Retrieval Abstraction Layer: Why RAG Tooling Choice Is a Margin Decision, Not a Stack Decision

Clients now ask for grounded, source-cited AI output, and the retrieval layer is where that promise is kept or broken. Agencies that hard-wire one context engine inherit its pricing and accuracy curve; those that put their own evaluation harness in front of the retrieval API can re-benchmark and swap providers as the market moves. The abstraction layer, not the vendor, becomes the billable asset.