Lineage is the New Audit Scope
Data lineage used to be documentation, the kind of internal record a bank kept for tidiness and produced on request, and that era is closing. Under the EU AI Act, high-risk systems including credit scoring and algorithmic trading must carry documented provenance for the data behind their decisions, with the high-risk rules enforceable from August 2026, and BCBS 239 has long required that risk data be complete, accurate, and traceable end to end. Lineage has moved from a filing habit to a thing examiners actively test.
The trouble is that most lineage is reconstructed after the fact. A team assembles, months later, an account of where a number came from, which sources fed it, and how it changed along the way. That reconstruction describes the ideal state, the way the pipeline was supposed to behave. Examiners test the actual state, and findings and fines accumulate in the distance between the two. A narrative built in hindsight can be honest and still be wrong, because it leans on memory, on documentation that may have drifted from the system it describes, and on the institution vouching for its own account.
Agents make the gap wider still, because an agent assembles its inputs at runtime, choosing sources and reconciling them on the fly, and generates far more lineage per decision than any after-the-fact process can faithfully capture. By the time a person sits down to document what the agent read, the moment has passed and the record is a reconstruction of a reconstruction.
Lineage is strongest when it is captured as the data is produced, by the system that served it, rather than described later by the system that consumed it. Provenance recorded at the source does not rely on anyone's memory or good faith, since it was written as the data moved rather than narrated afterward.
Space and Time provides that, as the data blockchain securing onchain finance. A query returns its result together with cryptographic proof that the computation ran correctly over tamperproof data, so the lineage of that result exists the instant the result does. There is no later reconstruction to reconcile against the actual state, because the proof is the actual state, generated at query time and verifiable by anyone.
The examiner's question is shifting from whether you can describe where a number came from to whether you can prove it. Lineage born with its own proof answers the second question without hoping the first was documented well enough to survive scrutiny.
