CellVerdict
CellVerdict is a multi-method consensus annotator and trust layer for single-cell RNA-seq data.
Core trick
Five independent annotators vote per cluster, and a Claude adjudicator reconciles those votes with computed doublet and ambient-RNA signals into one trust score.
Description
CellVerdict is a multi-method consensus annotator and trust layer for single-cell RNA-seq data. Cell-type annotation is the linchpin of every single-cell analysis — a wrong cluster label silently poisons downstream differential expression, cell-cell communication, and trajectory results while the UMAP still looks clean. Existing annotators each give an answer, often with unearned confidence, and they disagree with one another; a non-expert can't tell which to trust.
Instead of adding one more annotator, we built a council. Every cluster is annotated independently by five voices — a marker-database matcher (multiple curated reference DBs), a CellTypist ML classifier, a prior-studies voter that web-searches primary literature for the specific tissue and votes with clickable, citation-ranked PMIDs, and a grounded Claude annotator — on top of a deterministic evidence engine that computes doublet, stress, ambient-contamination, and marker-specificity signals. A separate Claude adjudicator then reconciles all the votes against the computed evidence into one final label, a green/yellow/red trust score, and natural-language reasoning that names which DBs, which model, and which papers drove the decision.
What we found: the fusion catches failures a single tool confidently mislabels — planted doublets and dying-cell states get flagged red instead of forced into a clean label — and that bad-label risk propagates downstream, so CellVerdict lists exactly which cell-cell communication interactions rest on a low-trust annotation. Give it an unlabeled dataset and it annotates; give it a labeled one and it audits. Every verdict is glassbox: click any node in the flow canvas to see the votes and the raw numbers behind them.
Why it matters: it turns a two-day, subjective, cluster-by-cluster eyeballing task into a two-minute, reproducible, citable trust report — and makes the risk in an annotation visible instead of hidden.
README excerpt
# CellVerdict **A citation-backed annotation trust layer for single-cell data.** [](LICENSE)  CellVerdict doesn't just put a **label** on each cluster of cells — it tells you **how much to trust that label**, shows **why**, and flags which downstream conclusions rest on shaky annotations. It fuses a marker database, an ML classifier (CellTypist), computed quality signals, prior-study evidence, and Claude's grounded reasoning into one **consensus verdict** per cluster, color-coded green / yellow / red. > Unlabeled input → it **annotates**. Already-labeled input → it **audits** your labels and > shows the mismatches. One engine, two modes. A tool, not a notebook. Python package: `cellverdict` · engine + CLI + FastAPI backend + React frontend. --- ## The problem Cell-type annotation looks simple but is quietly dangerous: if a cluster's label is wrong, **every conclusion built on it** — cell-cell communication, differential expression, trajectories — silently inherits the error. Existing annotators each give *an* answer, often with unearned confidence, and they **disagree** with each other. A beginner can't tell which to trust or where the risk is. CellVerdict's answer is a **trust layer**, not another annotator: a consensus you can **see, cite, and audit**. ## Why a council beats any single method Three techniques each solve annotation partially