MCPDBWizard MCP server

MCPDBWizard

An MCP server for Oracle, built from the objects you choose. Tick the PL/SQL packages, tables, sequences and your own tested SQL statements in a console, and it generates a Model Context Protocol server exposing exactly those to an AI agent as typed tools — each carrying a JSON Schema derived from the procedure's real signature.

There is no run-sql tool. Anything you did not select has no tool, no method and no class: it is absent from the binary rather than refused at run time. Nothing composes a query at run time either — the generated code is ordinary Java with fixed SQL statements and typed binds, and the MCP server calls those wrappers rather than writing SQL for a model to run.

Generating that server means generating the whole calling layer, so you get it too: typed DAO factories, callable-statement wrappers, table managers and an optional SOAP layer. They are useful on their own, but the MCP server is the point.

Supports Oracle 12c through 26ai, and is regression-tested against six live instances spanning that range.

The part that is hard

The usual way round is to hand the agent a run-sql tool, and it works until the schema is real: published text‑to‑SQL accuracy falls sharply on enterprise‑scale schemas compared with tidy benchmarks, and a wrong UPDATE is not a wrong answer, it is an incident.

The alternative is curated tools — but writing one per procedure by hand does not scale past a few, and PL/SQL is unusually hostile to deriving them automatically:

%ROWTYPEs, REF CURSORs, package types, and overloads

• a procedure can have any number of OUT and IN OUT parameters, not a single return value
• parameters can be records (including records nested inside records), collections,

• Oracle's own data dictionary describes these differently between versions

This project does that derivation. Every generated MCP tool carries a real JSON Schema built from the procedure's actual signature, so the agent is told what the parameters are rather than inferring them from prose.

oracle:  PROCEDURE order_summary(p_customer IN  NUMBER,
                                 p_totals   OUT summary_rec,
                                 p_lines    OUT SYS_REFCURSOR)

tool:    order_summary { "p_customer": <number> }
      -> { "p_totals": { "orderCount": 12, "value": 4210.55 },
           "p_lines":  [ { "sku": "AB-1", "qty": 3 }, ... ] }

A record crosses as a JSON object, a REF CURSOR as an array of row objects, a DATE as an ISO‑8601 string, RAW and binary vectors as base64, CLOB as text, BLOB as base64.

Quick start

Requires Java 21 and Maven. The Oracle JDBC driver (com.oracle.database.jdbc:ojdbc11) comes from Maven Central — nothing to install by hand.

mvn clean package

That produces two jars in target/: a plain one, and a self‑contained mcpdbwizard-app--shaded.jar with the driver bundled.

# Interactive (Swing) -- pick objects and options, save a config
java -jar target/mcpdbwizard-app-*-shaded.jar <log_dir> myconfig.pb2

# Batch -- regenerate from a saved config
java -jar target/mcpdbwizard-app-*-shaded.jar <log_dir> build myconfig.pb2

is created if missing.

Changed in 2026-08: there used to be a leading argument. It has been

removed, and a command line that still passes one will be read as the log directory.

It was validated for shape only — ≥19 characters, not a path, not the literal build —

and then ignored, so it authenticated nothing. Drop it from any script that supplies it.

Configs are .pb2 (a flat properties file) or .json; both are accepted, and convert losslessly either way:

java -cp target/mcpdbwizard-app-*-shaded.jar \
     com.mcpdbwizard.schema.ConfigConverter myconfig.pb2 myconfig.json

Shortened. The full README is on GitHub.