ai.nullary/nullary

Measured conclusion: Alive, not deep-tested. L2 outcome: not_attempted.

Negative results intelligence for drug discovery — query measured failures via MCP.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "nullary": {
      "url": "https://mcp.nullary.ai/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (35)

• search_inactive_compounds read-only

  Inactive small-molecule compound-target pairs.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_selectivity read-only

  Small molecules that failed selectivity.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_admet_failures read-only

  Small-molecule ADMET failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_guides read-only

  Failed/ineffective CRISPR guides.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_essentiality_screens read-only

  Non-dependency / failed essentiality screens.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_ancestry_specific_failures read-only

  Ancestry-specific CRISPR failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_developability_failures read-only

  Antibody developability failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_clinical_antibodies read-only

  Discontinued/terminated clinical antibodies.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_peptide_therapeutics read-only

  Failed peptide therapeutics.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_peptide_stability_issues read-only

  Peptide stability/half-life failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_protacs read-only

  PROTACs that failed degradation/ternary/permeability.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_protac_e3_issues read-only

  PROTAC E3-ligase recruitment / ternary failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_oligonucleotides read-only

  ASOs/siRNAs that failed engagement/developability.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_oligo_delivery_failures read-only

  Oligonucleotide delivery failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_vaccines read-only

  Failed/terminated vaccines (by pathogen/indication).

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • indication — string — disease/indication

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_vaccine_immunogenicity_failures read-only

  Failed vaccine immunogen designs.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_adcs read-only

  ADCs that failed at any stage.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_adc_linker_failures read-only

  ADC failures attributed to linker chemistry.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_bispecifics read-only

  Bispecifics that failed at any stage.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_bispecific_format_failures read-only

  Bispecific format/engineering failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_admet_failures_all_modalities read-only

  ADMET failures across ALL modalities.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_drug_drug_interaction_failures read-only

  Drug-drug interaction failures.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_mechanism_failures read-only

  Approaches that failed for a mechanism (by target).

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_failed_replications read-only

  Findings that failed to replicate.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_safety_failures read-only

  Clinical/preclinical safety failures across modalities.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • target — string — UniProt accession or gene symbol
  • outcome — string — outcome filter (inactive, failed_safety, terminated, …)
  • compound — string — compound name, ChEMBL ID, or InChIKey

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_target_history read-only

  ALL failed approaches against a target across every modality.

  Parameters:

  • target (required) — string — UniProt accession or gene symbol (required)
  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_indication_history read-only

  ALL failed approaches for an indication across every modality.

  Parameters:

  • indication (required) — string — indication (required)
  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• search_pathogen_history read-only

  Vaccine + antimicrobial + antibody failures for a pathogen.

  Parameters:

  • pathogen (required) — string — pathogen name (required)
  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_compound read-only

  A compound (structure, name, max clinical phase) + its full negative profile across modalities/sources.

  Parameters:

  • tier — string — Confidence tier. 'curated' (default) returns the credible layer; 'all' also includes high-volume screening-grade rows (PubChem HTS inactives, CRISPR non-essential tails).
  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • offset — integer — Number of findings to skip before this page, for pagination (default 0).
  • chembl_id — string — ChEMBL molecule ID, e.g. CHEMBL941.
  • inchi_key — string — Compound InChIKey (provide one of inchi_key, chembl_id, or pubchem_cid).
  • pubchem_cid — integer — PubChem Compound ID (CID).

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_finding_provenance read-only

  Full provenance + detail for a single finding by id.

  Parameters:

  • id (required) — string — finding UUID

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_target_landscape read-only

  Target 'graveyard' / exhaustion index: how many distinct compounds/agents have been tried against a target and failed, broken down by modality and outcome. Answers 'how picked-over is this target?'. Accepts a gene symbol (e.g. EGFR) or a UniProt accession (e.g. P00533).

  Parameters:

  • target (required) — string — gene symbol or UniProt accession (required)

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• list_top_targets read-only

  Coverage browse: the most heavily-pursued ('graveyard') targets, ranked by recorded negative findings. Optional family filter (kinase, gpcr, protease, nuclear_receptor, ion_channel, transporter, phosphatase, other).

  Parameters:

  • limit — integer — Maximum number of findings to return (1–100, default 25).
  • family — string — target family filter (optional)

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• list_models read-only

  Summary of the Layer-1 inactivity-scoring model registry: how many per-target models, split by family, and median scaffold-split ROC-AUC.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_model_card read-only

  Per-target Layer-1 model card: training counts and held-out scaffold-split metrics (ROC-AUC, PR-AUC, Brier, calibration). Accepts a gene symbol (e.g. EGFR) or UniProt accession (e.g. P00533).

  Parameters:

  • target (required) — string — gene symbol or UniProt accession (required)

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• get_coverage read-only

  Per-modality and per-source coverage stats (honest Phase-1 numbers).

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

Repository

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