Install & CLI

Install

CLI — installs the marsdb binary:

cargo install marsdb-cli

Or on macOS/Linux via Homebrew (tap):

brew install knoguchi/marsdb/marsdb

Usage

marsdb                                  # in-memory REPL
marsdb mydata.db                        # file-backed REPL
marsdb mydata.db "MATCH (n) RETURN n"   # run one query, exit
marsdb :memory: "..."                   # explicit in-memory, one-shot
marsdb mydata.db "CREATE (a); CREATE (b); MATCH (n) RETURN n"  # ;-separated batch
marsdb mydata.db < script.cypher        # piped stdin, same ;-separated batch
marsdb mydata.db --nl "who does Alice know?"  # plain-English question via Ollama

The REPL accepts any Cypher statement terminated by ;. Ctrl-D exits.

Natural language queries

--nl translates a plain-English question into Cypher and runs it, using a local Ollama instance:

ollama serve &
ollama pull llama3.2
marsdb mydata.db --nl "how many people are there?"

Set OLLAMA_MODEL to use a model other than the default llama3.2. The generated Cypher is printed before its results. Generated writes are rejected — --nl only ever runs read-only queries. The translation itself validates the generated Cypher’s syntax and variable/type binding against the database’s actual schema, retrying once with the validation error fed back if the first attempt doesn’t parse — see the marsdb-nl2cypher crate for the underlying library.

$ marsdb :memory:
MarsDB graph database. Enter Cypher statements terminated by `;`. Ctrl-D to exit.
marsdb> CREATE (a:Person {name: 'Alice'})-[:KNOWS]->(b:Person {name: 'Bob'});
marsdb> MATCH (a:Person)-[:KNOWS]->(b:Person) RETURN a.name, b.name;
a.name | b.name
Alice | Bob