ROBINS I V2 MCP

robins-i-mcp

An MCP server implementing ROBINS-I V2 (Risk Of Bias In Non-randomized Studies – of Interventions, follow-up/cohort variant) as a deterministic, provenanced assessment engine.

Sibling to target-mcp, which scores how completely a target-trial-emulation study reports what the TARGET guideline requires. This one assesses risk of bias in one specific result. The two are complementary on the same paper.

The source is a draft. riskofbias.info presents the 20 November 2025 release of ROBINS-I V2 as still a draft, subject to change. Every report stamps that in its provenance line. See NOTICE and TRANSCRIPTION-NOTES.md.

Follow-up cohort studies. "Follow-up" and "cohort" name one structural property — a defined time zero, individuals followed forward under the contrasted strategies — so read the property, not a design label. Target trial emulations are the central use case and are cohort studies in exactly this sense; both worked examples below are TTEs. Designs with no follow-up structure are out. No variant for other designs is published yet. Note that "Variant A / Variant B" inside the tool means the two forms of Domain 1 selected by C4 — not a study design.

What makes it different from asking a model

The model's contribution is bounded at answering signalling questions from the text. It cannot compute a judgement and it cannot invent evidence.

1  parse_document              PDF + supplement → SectionMap        deterministic
2  cue detection               where to look, per domain            deterministic
3  answer signalling questions quotes copied from the bundle        MODEL
4  evidence binding            quotes → offsets, or REJECT          deterministic
5  algorithms                  answers → domain → overall           deterministic
6  report + render             stamped artifact                     deterministic
7  human ratification          P1, reviewer-prior answers, overrides

Three rules are enforced at submission, and they are the point of the server:

• Quotes resolve or die. Every quote is matched to character offsets in the ingested bundle through a three-pass ladder (exact → hyphen-relaxed → references-stripped), and the winning pass is recorded so a loose match is never silently equated with an exact one. An unresolvable quote is rejected with the nearest actual text.
• Absence is searched, not asserted. A manuscript_absent answer names a cue; the server runs the search and attaches the record — terms, sections, hit count. A prose claim that you looked is refused.
• Judgements are computed. No tool accepts a domain judgement as input. The six domain algorithms and the overall algorithm are explicit edge graphs traced from the published flowcharts. A human may override, with a recorded justification, and the report shows both values.

Two gates

P1 blocks domain 1. Question 1.1 asks whether all important confounding factors were controlled, and "important" is defined by the reviewer's prespecified list — not by the paper's covariate table. The server refuses to score domain 1 without set_prespecified_confounders rather than silently substituting one for the other. A list you propose is a candidate: it enters the ratification queue until a human accepts it.

C4 selects domain 1's question set. Whether the analysis accounts for protocol deviations picks variant A (intention-to-treat, baseline confounding only) or variant B (per-protocol, baseline and time-varying confounding), so specify_result requires it up front with no default. Judge it on what the analysis does, not on the label the authors give their estimand — on the reference paper, the protocol table says "per-protocol effect" and the analysis is intention-to-treat.

Install

pip install robins-i-mcp

Then register it with your MCP client:

{ "mcpServers": { "robins-i": { "command": "robins-i-mcp" } } }

Or run it with no install at all:

uvx robins-i-mcp

Also on the MCP registry as com.blackswancausallabs/robins-i-mcp.

Develop

python3 -m venv .venv && .venv/bin/python -m pip install -e ".[dev]"
.venv/bin/python -m pytest tests/ -q      # 205 passed
.venv/bin/robins-i-mcp                    # stdio MCP server

Tools

Scaffolds are per domain, never one flat rubric: most signalling questions are unreachable on any given path, and which of domain 1's two sets exists at all depends on C4.

Pass the supplement. The target-trial specification that settles C1–C4, and the analysis detail domains 1 and 4 turn on, routinely live only in the appendix. Without it, those questions read NI when the answer was merely in a file nobody ingested.

Many studies: the record

A review of N studies is N runs. Each assessment costs a session, and the server keeps no state between them. So each run emits a small portable record — that is the deliverable that crosses the boundary:

session 1..N   assess one result -> save submit_answers(domain=0)['record']
later          export_robvis(records=[...]) -> one figure-ready CSV

A record is ~4 KB of flat JSON and depends on nothing in this codebase, so any later agent can consume it. It carries its own provenance — document hash, algorithm fingerprint, spec version, ratification state — so every row in the resulting figure traces back to a document, and the export can warn when a set mixes algorithm transcriptions.

export_robvis is not a column dump. robvis's ROBINS-I template is V1: seven domains, and V1 orders selection of participants before classification of interventions, which V2 swaps. The default layout places each V2 judgement in its correct V1 slot; a positional dump would parse, plot, and lie. Read the returned losses before publishing — robvis reduces every cell to its first initial over a five-fill palette, so the qualified low collapses to Low there whatever string is written.

See examples/review_from_records.py.

Worked examples

.venv/bin/python examples/dickerman_2022.py out.html          # library level
.venv/bin/python examples/jabagi_2026_server_run.py           # server level
.venv/bin/python examples/review_from_records.py             # across runs

• Dickerman et al., NEJM 2022 — BNT162b2 vs mRNA-1273 in US veterans. Comes out low, except for concerns about uncontrolled confounding. 24 of 41 questions never reached.
• Jabagi et al., Lancet Reg Health Eur 2026 — maternal RSVpreF vs infant RSV hospitalisation. Comes out serious, and the route is worth reading: domain 1 fails at 1.3 rather than 1.1, because gestational age at birth and birth weight are matched on despite being realised after the intervention.

The papers themselves are not in this repository — they are published articles and not ours to redistribute. Put your own copies in papers/, or point ROBINS_MCP_PAPERS at the directory holding them; the examples name the files they need and fail with that message if they are absent.

Documentation

• docs/STATUS.md — current state and handoff. Read this first.
• docs/DECISIONS.md — why things are the way they are, newest first.
• docs/SESSION-NOTES-*.md — per-session narrative.
• TRANSCRIPTION-NOTES.md — how the algorithms were obtained from raster flowcharts, the errata found in the published document, and what still needs external verification.

Licence

Apache-2.0 (LICENSE). The ROBINS-I V2 tool it implements is CC BY-NC-ND 4.0 and no part of it is reproduced here — see NOTICE for why that matters and what the actual constraint is.