NCATS ARAX

Use ARAX as a constrained knowledge-graph lookup service. Submit reviewed CURIEs and explicit Biolink types, preserve the exact TRAPI exchange, inspect query-edge bindings and provenance, and treat every returned path as a candidate for subsequent verification.

Endpoint: https://arax.transltr.io/api/arax/v1.4 — POST TRAPI, no key. Checked against: the live production service, August 2026 — preflight reports ARAX 1.5.4 and TRAPI 1.5.0, the versions this client is pinned to.

Read query-contract.md before constructing a query. Read output-schema.md when interpreting saved artifacts, warnings, provenance, or partial results.

Safety boundary

• Use only public, nonsensitive research questions. ARAX status facilities may expose query and caller metadata even when store=false is requested.
• Do not submit patient information, confidential research questions, unpublished compound programs, or proprietary target hypotheses.
• Do not present a returned path as a validated mechanism or clinical recommendation.
• Report a zero as "not returned under these constraints," never as evidence that no relationship exists.
• Describe position as unscored response order, never rank.
• Verify important candidates with literature and authoritative databases separately.

Workflow

1. Normalize free text separately, then review and report the proposed CURIE and category.
2. Choose a typed one-hop query or an exactly two-hop query with both endpoints pinned.
3. Use default RTX-KG2 lookup unless the user explicitly names two to five providers.
4. Acknowledge that the biomedical query is public and choose a new or empty output directory.
5. Run the client once. Do not silently change provider selection or expansion order after a failure or empty result.
6. Inspect summary.json for bounded bindings and provenance and response.json for the exact TRAPI payload.
7. Verify scientifically important paths outside ARAX.

Preflight

Check the production OpenAPI without making a biomedical query:

python skills/ncats-arax/scripts/arax_client.py preflight

The client verifies that the service identifies itself as ARAX, exposes /query, and reports a supported TRAPI version. A nonproduction endpoint or untested TRAPI series requires an explicit override; neither override changes the fixed query shapes or operations.

Normalize an entity

Normalization is review-only and never triggers a graph query:

python skills/ncats-arax/scripts/arax_client.py normalize "primary myelofibrosis" \
  --expected-category biolink:Disease \
  --max-synonyms 10 \
  --acknowledge-public-query \
  --output-dir outputs/normalize-myelofibrosis

Review the canonical identifier, name, category, and synonym preview before using a CURIE. Report all CURIEs and categories regardless of query outcome. A category warning or zero result is a reason to curate the identifier, not to chain automatically to /query.

One-hop lookup

Pin at least one endpoint and type both nodes:

python skills/ncats-arax/scripts/arax_client.py one-hop \
  --subject-id CHEBI:31690 \
  --subject-category biolink:SmallMolecule \
  --predicate biolink:affects \
  --object-id NCBIGene:25 \
  --object-category biolink:Gene \
  --qualifier biolink:object_aspect_qualifier=activity_or_abundance \
  --qualifier biolink:object_direction_qualifier=decreased \
  --acknowledge-public-query \
  --output-dir outputs/imatinib-abl1

Lookup mode is the default and fixes expansion to infores:rtx-kg2. It defaults to 20 results. Use --result-limit N to request 1-50 results; 50 is the hard cap in either mode.

Endpoint-pinned two-hop lookup

Use exactly one typed, unpinned intermediate node:

python skills/ncats-arax/scripts/arax_client.py two-hop \
  --subject-id CHEBI:66901 \
  --subject-category biolink:SmallMolecule \
  --predicate-1 biolink:affects \
  --intermediate-category biolink:Gene \
  --predicate-2 biolink:associated_with \
  --object-id MONDO:0009061 \
  --object-category biolink:Disease \
  --qualifier-1 biolink:object_aspect_qualifier=activity_or_abundance \
  --qualifier-1 biolink:object_direction_qualifier=increased \
  --expand-order right-first \
  --acknowledge-public-query \
  --output-dir outputs/ivacaftor-cystic-fibrosis

Right-first expansion is the default. If an empty result merits another attempt, run a new query explicitly with --expand-order left-first and keep the runs separate.

Selected-provider federation

Federation is explicit and accepts two to five named providers:

python skills/ncats-arax/scripts/arax_client.py one-hop \
  --subject-id CHEBI:31690 \
  --subject-category biolink:SmallMolecule \
  --predicate biolink:affects \
  --object-id NCBIGene:25 \
  --object-category biolink:Gene \
  --mode federated \
  --kp infores:rtx-kg2 \
  --kp infores:molepro \
  --acknowledge-public-query \
  --output-dir outputs/federated-imatinib-abl1

Federation defaults to the hard maximum of 50 results. Provider errors may coexist with useful results; such a run exits 7 after retaining its artifacts and is marked partial.

Inspect saved provenance

Rebuild a bounded summary without network access:

python skills/ncats-arax/scripts/arax_client.py summarize \
  --request outputs/ivacaftor-cystic-fibrosis/request.json \
  --response outputs/ivacaftor-cystic-fibrosis/response.json \
  --format text

The inspector accepts only the same constrained request shapes and fixed operations that the live commands generate. Use --format json for the normalized view on standard output.

Interpret results

• Follow each analysis's query-edge bindings; do not summarize every knowledge-graph edge.
• Preserve the physical edge subject, predicate, object, and qualifier values returned by ARAX. Returned predicates or qualifier aspects may be more specific than the query constraint.
• Inspect all source objects, including primary, aggregator, supporting-data, upstream-resource, and source-record URL fields.
• Treat publication_availability: not_returned as missing metadata, not evidence that no publications exist.
• Treat missing auxiliary-graph references and provider failures as explicit warnings.
• Consult the raw response whenever the bounded summary omits detail or the service response is partial, unfamiliar, or scientifically surprising.

Deliberate exclusions

The client has no raw-query, workflow, operation, overlay, ranking, inference, link-prediction, Pathfinder, ARS, batch, all-provider, three-hop, cache, daemon, SDK, MCP, or natural-language-to-TRAPI surface. Do not work around those limits with direct HTTP calls under this skill.

Composing with the rest of the bundle

• open-targets → before: it scores whether a target-disease link is supported and by which datatype. Come here when you need the mechanistic path and the source attribution behind it.
• primekg → alongside: the same kind of graph as a local CSV, faster to traverse in bulk but without ARAX's per-edge provenance. Use PrimeKG to generate candidates, ARAX to attribute them.
• target-safety / depmap → after: a returned path is an assertion, not a validated mechanism. Human genetic constraint and cell-line essentiality test it against something measured.
• chembl → after: whether chemistry exists against a protein a path implicates.
• clinicaltrials / openfda → after: whether the hypothesis has already been taken into people, and what happened.

Provenance is the reason to use this skill. Every edge names its knowledge source; a path assembled from infores:text-mining-provider edges is a different claim from one assembled from curated sources. Read the attribution before reporting the path.

Official references

• ARAX documentation
• ARAX production OpenAPI
• ARAXi operation documentation
• Translator Reasoner API
• Biolink Model