Graph and Gremlin Gateway

26.3.1GraphGremlin

MonkDB includes graph metadata, graph SQL helpers, and a Gremlin HTTP gateway.

SQL graph model

CREATE GRAPH <name>
CREATE VERTEX TABLE ... FOR GRAPH ... KEY ...
CREATE EDGE TABLE ... FOR GRAPH ... SOURCE KEY ... TARGET KEY ...

End-to-end example

CREATE GRAPH social;

CREATE TABLE doc.users (
  id TEXT PRIMARY KEY,
  name TEXT,
  segment TEXT,
  embedding FLOAT_VECTOR(4),
  event_ts TIMESTAMPTZ,
  metric DOUBLE PRECISION
);

CREATE TABLE doc.follows (
  src_id TEXT,
  dst_id TEXT,
  event_ts TIMESTAMPTZ,
  weight DOUBLE PRECISION,
  PRIMARY KEY (src_id, dst_id)
);

CREATE VERTEX TABLE doc.users FOR GRAPH social KEY id;
CREATE EDGE TABLE doc.follows FOR GRAPH social SOURCE KEY src_id TARGET KEY dst_id;

INSERT INTO doc.users (id, name, segment, embedding, event_ts, metric) VALUES
  ('1','Alice','creator',[0.91,0.07,0.01,0.22],'2026-02-23T10:00:00Z',12.4),
  ('2','Bob','viewer',[0.11,0.80,0.05,0.33],'2026-02-23T10:05:00Z',8.1);

INSERT INTO doc.follows (src_id, dst_id, event_ts, weight) VALUES
  ('1','2','2026-02-23T11:00:00Z',0.9);

REFRESH TABLE doc.users, doc.follows;

SELECT * FROM graph_edges('social') ORDER BY table_name, source_vertex, target_vertex;
SELECT * FROM graph_neighbors('social', '1') ORDER BY neighbor_vertex;
SELECT vertex, depth, path FROM traverse('social', '1', 2) ORDER BY depth, vertex;

Gremlin HTTP gateway

Endpoints:

/_gremlin and /gremlin
/_gremlin/capabilities
/_gremlin/conformance
/_gremlin/stats

Request JSON fields:

Required: graph, gremlin
Optional: max_depth, max_rows, timeout_ms, request_id
Compatibility payloads: op=eval, args, bindings, aliases

Policy and guardrail defaults

max_depth=8
max_rows=10000
timeout_ms=30000
deny_unbounded_repeat=true

Admission defaults:

assumed_fanout=16
max_estimated_rows=500000
max_estimated_work=2000000