Ownership Boundary

Index authority is execution-contract authority over vectors. It binds a request and immutable artifact to an eligible backend, records what happened, and evaluates later replay without claiming what the result means.

flowchart TD
    change{"Which guarantee changes?"}
    prepare["document or chunk representation"]
    execute["vector contract, backend, rank, replay"]
    support["claim support and reasoning verification"]
    roles["role lifecycle and convergence"]
    flow["flow acceptance and tenant authority"]

    change --> prepare --> ingest["ingest"]
    change --> execute --> index["index"]
    change --> support --> reason["reason"]
    change --> roles --> agent["agent"]
    change --> flow --> runtime["runtime"]

Decision table

Change	Owner	Reason
change normalization or chunk overlap	ingest	changes prepared content and identity
change stable tie-breaking or metric semantics	index	changes governed ranking behavior
add an ANN parameter to plan identity and replay comparison	index	changes approximation and provenance contract
decide whether a passage entails a proposed statement	reason	changes support interpretation
run a verifier role again after a veto	agent	changes workflow progression
accept bounded replay for a complete tenant flow	runtime	changes final workflow authority

Ingest and index retrieval

Ingest supplies a compact local BM25/NumPy path for document preparation, evaluation, and extractive citation. Index becomes the owner when retrieval requires an immutable execution artifact, explicit exact/ANN contract, capability-selected backend, governed budget, cross-run provenance, or replay comparison.

The handoff should retain document, chunk, vector, embedding/configuration, and corpus identity. Index must not silently clean or rechunk input to satisfy a backend; doing so would make artifact identity dishonest.

Index and reason evidence

Index can explain why a result occupied a rank by joining its query, vector, metric, score, backend, artifact, and execution. Reason decides whether the retrieved content supports a claim. A result explanation is necessary provenance, but it is not claim verification.

Ranking custody

flowchart LR
    prepared["prepared document + chunk + vector identity"]
    artifact["immutable execution artifact"]
    request["intent + contract + metric + budget"]
    plan["eligible backend + exact/ANN plan"]
    candidates["candidate execution"]
    result["ordered result + cost + provenance"]
    support["reason-owned support decision"]

    prepared --> request --> artifact --> plan --> candidates --> result
    result -. "evidence handoff" .-> support

Index owns the solid path from artifact materialization through ranking. It does not own the prepared text/vector semantics before the artifact or the claim-support decision after the result.

Minimum retrieval handoff

Field	Why the consumer needs it
request, artifact and execution identities	binds the result to immutable inputs and declared intent
document/chunk/vector and embedding identities	preserves the preparation objects that were ranked
metric, dimensions and normalization assumptions	makes score semantics interpretable
backend, capability report and implementation identity	explains eligibility and operational behavior
exact/ANN classification, parameters and randomness sources	prevents approximate output from being described as exact
candidate, rescore and final ordering path	exposes how the final rank was produced
budget/cost, partial status and typed failures	prevents truncated work from appearing complete
provenance, fingerprints and replay policy	permits later explanation and comparison

Reason may select exact bytes from a returned chunk and decide whether they support a claim. It must retain this retrieval packet rather than replacing it with rank alone.

Resolve ambiguous failures

Symptom	First record to inspect	Owner when that record is false
chunk text or vector differs before execution	preparation identity and embedding specification	ingest
declared metric cannot run on the artifact dimensions	request/artifact validation and capability decision	index
ANN candidate set changes outside its declared envelope	plan, randomness, backend and replay comparison	index
correct ranked result is cited with the wrong byte span	evidence/support record	reason
correct index result is lost or reordered during role merge	agent shard/merge lineage	agent
valid result is prohibited by flow/tenant policy	runtime authority and arbitration	runtime

Detection location does not transfer ownership. Retain the upstream identity and route the defect to the first false invariant.

Ownership test

Ask which record must change for the behavior to become correct. If it is a prepared document or chunk, use ingest. If it is an execution request, artifact, backend capability, score, run record, or replay comparison, use index. If it is a support reference or verification finding, use reason.