Documentation

VFBquery API

VFB’s general-purpose query API — term information, search, connectivity, cross-references, FlyBase stocks and combinations, and the CATMAID pass-through — all as simple read-only JSON calls.

30 Aug 2026

VFBquery is the query service behind most of what the VFB website itself does — the term information panel, the search box, the hierarchy browser, connectivity queries, stock lookups — exposed as a plain JSON HTTP API anyone can call directly. It’s the same recommended entry point as the CATMAID pass-through, which is one part of this service:

https://v3-cached.virtualflybrain.org/

Every endpoint is a read-only GET (the CATMAID pass-through also accepts POST — see its own page) returning JSON, with no API key or account needed.

Interactive docs and the full spec

As with the CATMAID pass-through, the endpoint list changes over time, so it isn’t duplicated in full here. The authoritative, always-current reference is the service itself:

  • https://v3-cached.virtualflybrain.org/ — browsable docs for every endpoint, with a “Run” button to try a call directly.
  • https://v3-cached.virtualflybrain.org/docs.json — the same catalogue as machine-readable JSON.

What follows is a guided tour of the main groups of endpoints, to help you find the right one.

Term information

  • /get_term_info?id=FBbt_00003748 — the full report behind the website’s term information panel for one VFB or FBbt id: metadata, synonyms, relationships, aligned images, cross-references, and the list of named queries that can be run from the term.
  • /run_query?id=FBbt_00003748&query_type=ListAllAvailableImages — runs one of the named query types listed in a term’s /get_term_info response (e.g. ListAllAvailableImages), in the website’s own row format. Supports offset/limit paging.
  • /get_hierarchy?id=FBbt_00005801&max_depth=1 — the hierarchy browser’s tree: follows one relationship (part_of or subclass_of) from a term, upward, downward, or both.

Search and identifiers

  • /search?query=medulla&limit=10 — the same ranked free-text search the website uses. filter_types/exclude_types/boost_types/demote_types narrow or re-rank by type.
  • /facets — the vocabulary of type names /search’s type parameters accept.
  • /xref?id=VFB_001011rj — cross-reference lookup in either direction: id= for VFB id → external accessions, or accession= (optionally with db=) for external id → VFB.
  • /combine?expr=calyx AND lh&calyx=...&lh=... — set algebra (AND/OR/NOT/XOR and friends) over two or more named query results, compared on term id, with every step traced in the response.

Connectivity

  • /list_connectome_datasets — the connectome datasets /query_connectivity can draw on.
  • /query_connectivity?upstream_type=LPLC2&downstream_type=giant fiber neuron — synaptic connectivity from one neuron type (or any subclass) to another, summed across the connectomes. Types can be given as labels, synonyms or FBbt ids.

FlyBase stocks and combinations

  • /resolve_entity?query=dpp — free-text resolver for a gene, allele or transgene name, returning candidate FlyBase feature ids.
  • /find_stocks?id=FBgn0000490 — stock-centre holdings for a resolved feature id.
  • /resolve_combination?query=GMR37H08-ZpGAL4DBD in attP2 — resolver for split-GAL4 hemidriver combinations, returning FBco ids.
  • /find_combo_publications?id=FBco0000052 — publications using a resolved combination.

CATMAID pass-through

/catmaid, /catmaid/{instance} and /catmaid/{instance}/{command} proxy VFB’s hosted CATMAID instances, converting between VFB ids and native skeleton ids (skids) along the way. This is documented in full, with worked examples, on its own page: CATMAID API.

Service

  • /health — a plain OK liveness check.
  • /status — queue depth, cache hit/miss counts and worker utilisation.

force_refresh and caching

v3-cached.virtualflybrain.org caches responses for speed. Most endpoints that reflect fast-changing data accept force_refresh=true to bypass the cache for that one call — see the individual endpoint’s parameters on the interactive docs page.