The verification engine.
The engine sits between the model and the tool. Everything that enters becomes a typed fact with a citation. Everything that leaves carries the chain that produced it. This is the substrate that lets an agent take consequential action without inheriting the model’s failure modes. Verification is not a layer on top. It is what the engine does.
Inputs in, verified artifacts out, chain attached.
Every fact in the substrate sits in one of four states: extracted, computed, unverified, or in disagreement. The state determines what the engine will do with it. The verdict colors in the substrate below map directly to these states.
What the engine does, every run.
When a workspace runs, the engine executes the four passes over its typed facts. Each pass is independent. The results compose into the proof chain for every output.
Source verification
Does the value actually appear in the source at the cited coordinate.
This is the check that catches extraction errors. OCR misreads, table parser drift, model fabrication. Run mechanically by comparing the extracted value to the source text at the citation.
Identity verification
Do the rules in the rule library hold against the facts.
Definitional identities and constraints are formulas. The engine plugs the workspace facts into them and checks the result. A failed identity is a hard finding.
Cross-source verification
Do the sources agree on facts more than one of them speaks to.
Facts are paired on (entity, metric, period) triples and compared. Disagreements are classified by severity. Detailed on the cross-source page.
Independent computation
For every value that can be derived, derive it and compare.
Two paths to the same number is a stronger guarantee than either path alone. If extraction and re-derivation agree, the value is verified in a way no single reading can match.
Disagreements are findings, not errors.
The engine’s job is to find them, classify them, and present them. The user’s job is to adjudicate. The system records the decision and the decision becomes part of the chain.
Small delta. Informational.
Rounding, restatement, presentation convention. Surfaced as informational. The user sees it. The output is not blocked.
Large enough to require a decision.
The user must adjudicate before the output is produced. Surfaced as a blocking gate. The decision is recorded as part of the chain.
An identity cannot hold under any reading.
The balance sheet cannot balance. The system cannot pick a side. Surfaced as a hard finding. Output blocked until the underlying conflict is resolved.
The engine your agent posts to.
Every proposed action goes through the four passes. The verdict comes back with the full chain attached. Wire this in once and your agent stops acting on facts it cannot defend.