Nullary
15.6M high-confidence findings, live

Negative results intelligence for drug discovery.

Turn dead-ends into your next breakthrough.

Big pharma's accumulated failure data is a competitive moat.Nullary makes that intelligence accessible to everyone else.

Structured access to failed compounds, terminated trials, failed CRISPR screens, and antibody developability data — installable as an MCP server in 30 seconds.

122M+ measured negative findings39.1M target-annotated compounds398 calibrated per-target modelsValidated under temporal split
What's inside

Seven modalities, one schema

A unified, citable record of what failed — normalized across public databases for each therapeutic modality.

85.2M

Small molecules

Rich coverage

Inactive compounds, failed selectivity, and ADMET liabilities.

ChEMBLPubChem BioAssayBindingDB
37.6M

CRISPR

Rich coverage

Failed essentiality screens and non-performing guide RNAs.

DepMapBioGRID ORCSGenomeCRISPR · soon
3.6K

Antibodies

Moderate — Phase 2 expansion in progress

Developability failures — aggregation, polyreactivity, expression.

Thera-SAbDabSAbDab · soonOAS · soon
18.8K

Peptides

Moderate

Stability, oral bioavailability, and immunogenicity dead ends.

THPdbPepLife · soonDrugBank · soon
824

PROTACs

Thin — Phase 2 expansion in progress

Ternary-complex, degradation, and hook-effect failures.

PROTAC-DBPROTACpedia
144

Oligonucleotides

Thin — Phase 2 expansion in progress

Target engagement, delivery, and hepatotoxicity failures.

AOBase · soonDrugBank · soon
282

Vaccines

Immunogenicity, efficacy, durability, and safety failures.

VIOLINFDA CBER · soon
Try it live

Query 15.6M high-confidence negative results, right now.

No install, no key. 120M+ total including screening-grade. Search the live dataset by modality, compound, target, or trial — every result citable to its source.

terminated phase-3 oncology trialsinactive kinase inhibitorsimatinibfailed antibody developability
Open the demo
How it works

From install to evidence in four steps

  1. 01

    Install

    Add the MCP server to Claude, Cursor, or any MCP client in 30 seconds.

  2. 02

    Query

    Search millions of negative findings by target, compound, indication, or trial — in natural language or over REST.

  3. 03

    Cite

    Every result carries provenance: DOI, PMID, source URL, license, and verification status.

  4. 04

    Build

    Ground models and pipelines in what didn't work. Stop re-running dead ends.

Get started

Install the MCP server in 30 seconds.

Add Nullary to Claude, Cursor, or any MCP client — or call the REST API directly. Free tier, no API key required.

Install MCPView docs
Add to CursorAdd to VS Code

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "nullary": {
      "url": "https://mcp.nullary.ai/mcp",
      "env": {
        "NULLARY_API_KEY": "free-tier-no-key-required"
      }
    }
  }
}
Evaluate the data and methodology: read our two technical reports →