# Evidence workbench The Evidence workbench lets a reviewer move from a question to the source passages selected for it. It is the start of an authoring environment: a reviewer can inspect the interpretation and export a proposed correction. It does not change the source or decide a person's entitlement. ## Search, Ask OKF and the workbench - **Search** finds potentially relevant records. - **Ask OKF** assembles a bounded evidence package and records how it selected each item, which relationships it followed and what remains missing. - **Evidence workbench** opens a retained package for inspection. It does not secretly rerun the question or replace the evidence with a model answer. - **An AI answer** is a separate interpretation of that package. The workbench neither generates nor certifies an answer. Open `/evidence/` in Explorer and supply a workbench manifest URL. A manifest is a small catalogue of public questions and links to their exact evidence. The URL can retain `manifest`, `case`, `record` and `tab` parameters for sharing. For source passage boundaries, open `/evidence/passages/` and supply a passage review manifest. This separate view checks one case at a time against its versioned, hash-bound source extraction. It renders a verified PDF page beside its exact extracted text, with current and proposed units below. It accepts a local split, join or role correction as a preview and exports a review record; it does not adopt that correction. See the [passage review profile](../profiles/evidence-workbench-passages/v1/index.md) for the manifest, case and correction contracts. ## Review a question 1. Choose a question. Only that question's package is downloaded. 2. Read the original question review brief, then its current evidence status, budget omissions and unresolved requirements. Original expectations are labelled separately from the engine’s current findings. 3. Choose a selected record. Open the cited PDF page beside its extracted text. 4. Use the tabs to inspect the whole passage, source spans, conceptual relationships, dependencies and selection trace. 5. Open the complete machine-readable package or export a local review proposal. A PDF page number identifies a location. A logical unit groups text which belongs together, potentially across several pages. A discovery card is a short description used to find that text. Neither the card nor a relationship label changes the authority of the underlying evidence. Source publication dates and capture dates are displayed separately; absent dates remain unknown. The interface links to the cited page. It does not imply word-level PDF highlighting when the package contains no bounding coordinates. A remote PDF may decline to display inside a frame; its ordinary source link remains available. ## Manifest and delivery contract `okf-evidence-workbench.v1` contains a title and a bounded `questions` array. Each entry supplies `id`, `label`, the exact `question`, and a `package` reference with URL, SHA-256 checksum and optional byte count. Optional `parts` references carry existing `okf-evidence-read.v1` package slices. The reconstructed document must be the existing `okf-governed-context.v1` package. The loader requires HTTPS, with HTTP allowed only for local development. Evidence references stay within the manifest's origin and directory. It rejects path escapes, credentials, unexpected redirects, mismatched checksums and malformed packages. Source links are untrusted data, never instructions. `packageContextForDelivery` reuses the context delivery primitives. It exports catalogues and exact package slices with a maximum response body of 32 KiB. This is a **delivery limit**, separate from the assembly limit of up to 512 KiB. It verifies complete reconstruction, provenance, omissions and context identity before reporting success. The reader bounds part count and cumulative bytes. Recorded response sizes describe serialised bodies, not measured HTTP traffic. ## Source-bound discovery The existing `okf-bm25.v1` behaviour remains unchanged. A producer can opt into `okf-bm25-weighted.v2`, which gives the authored discovery channel a declared weight of two and source text a weight of one. Bounded, source-bound navigation routes can prioritise a card; every selected route remains inspectable and is checked against the hashed card when loaded. These routes propose where to look, not what the law means. The engine contains no benefit names or paragraph IDs. A route can declare conjunctive groups of literal alternatives: all groups must match, including an explicit scope group. The card's declared scope also gates its lexical nomination. Missing scope is reported as a navigation omission; it does not establish that the source is legally inapplicable. Pattern and candidate counts are bounded, and exact spelling alternatives remain producer-authored. For this opt-in mode, the leading discovered source unit's outgoing dependencies are considered before broad concept expansion spends the resource budget. Unmatched guards, missing targets and truncation still remain visible. The ranking change cannot by itself prove that a selected passage answers a question. ## Review and publication boundary Review exports are local proposals linked to the package and record identities. They require normal source review and a separately authorised publication change before becoming part of a bundle. There are no write-capable remote tools. Opening a saved package is not a fresh source check or an external MCP-client acceptance test. A deployment must publish the matching producer data and consumer, then verify the actual journey. The first producer is OKF-DWP's 40 public staff-question occurrences. Other bundles can use the same contracts without importing DWP-specific logic. ## Page tools and shared views The [page tools guide](workbench-page-tools.md) explains optional WebMCP access, bounded evidence reads and the shared graph, interaction, requirements, rates and calculation-readiness views. The page renders the same typed data returned to a compatible AI client. Optional source-bound model proposals add inspection without changing the saved evidence packages. Calculation execution remains unavailable. See the [design decision](adr-workbench-page-tools.md) and [verification record](workbench-tools-verification.md) for the separate gates.