
Orionbelt Analytics
io.github.ralfbecherPublished by GitHub account ralfbecherv0.5.0Updated Oct 24, 2026
Ontology-based MCP server for database schema analysis and RDF/OWL ontology generation
Overview
Ontology-based MCP server that analyzes relational database schemas, generates RDF/OWL ontologies, and runs validated Text-to-SQL with charts.
- What you can do
- Connect to and inspect databases: connect, list databases and schemas, discover schema structure, get table details, reset cache, clean up workspace
- Build and manage ontologies: generate RDF/OWL ontologies with SQL mappings, suggest and apply semantic names, load custom Turtle files, validate relationships, download ontology or R2RML artifacts
- Query and visualize: sample table data, execute SQL with deterministic ontology-based checks and fan-trap detection, render Plotly charts
- Explore schemas with GraphRAG: semantic search, optimized SQL context, join-path discovery, reachability and measure planning
- Work with RDF: store ontologies in an Oxigraph store, run SPARQL queries, add metadata…
- When to use it
- Useful when an assistant needs to explore an unfamiliar relational database, produce a reusable ontology or semantic model, or generate SQL that is checked against the schema before it runs. Also fits teams wanting fan-trap-aware aggregation and chart output inside an MCP client.
- Requirements
- Runs locally as a Python package (Python 3.13+ and uv per the README). Database credentials are supplied through a .env file, for example POSTGRES_HOST, POSTGRES_PORT, POSTGRES_DATABASE, POSTGRES_USERNAME and POSTGRES_PASSWORD. The server listens on a local HTTP port (MCP_SERVER_PORT) that the client connects to, and network access to the target database is needed.
Installation
In SourceWeft
- Open Orionbelt Analytics in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
OrionBelt® Analytics
The Ontology-based MCP server for your Text-2-SQL convenience.
[Version 2.2.2] [Python 3.13+] [License: BUSL-1.1] [FastMCP 4.0.5+] [RDF/OWL]
[BigQuery] [PostgreSQL] [Snowflake] [ClickHouse] [Dremio] [Databricks] [DuckDB] [MySQL]
[Docker Hub] [Docker pulls] [Image size]
OrionBelt Analytics is an MCP server that analyzes relational database schemas and generates RDF/OWL ontologies with embedded SQL mappings. It provides relationship-aware Text-to-SQL with automatic fan-trap prevention, GraphRAG for intelligent schema discovery, and interactive charting -- all accessible through any MCP-compatible AI client.
The OrionBelt Ecosystem
Run Analytics and Semantic Layer side-by-side in Claude Desktop for schema-aware ontology generation and guaranteed-correct SQL compilation.
Architecture
[OrionBelt Analytics Architecture]
- 8 database connectors -- PostgreSQL, MySQL, Snowflake, ClickHouse, Dremio, BigQuery, DuckDB/MotherDuck, Databricks SQL
- RDF/OWL ontology generation with
oba:namespace SQL annotations and W3C R2RML mappings - GraphRAG -- graph traversal (up to 12 hops) + ChromaDB vector embeddings for semantic schema discovery, run locally; a multilingual option lets questions in other languages find the schema (German "Umsatz" finds a column named "Net revenue")
- SPARQL 1.1 query interface via persistent Oxigraph RDF store
- OBQC validation -- deterministic SQL checks against the ontology (table/column existence, join validity, type mismatches, fan-traps)
- Interactive charting -- Plotly charts with MCP-UI rendering in Claude Desktop
- Multi-schema support -- analyze multiple schemas simultaneously; ontology and GraphRAG state are isolated per schema
- Workspace persistence -- reconnect to the same database and restore your previous session
- MCP sampling -- when the connected client supports sampling (e.g. OrionBelt Chat),
suggest_semantic_namesasks the host LLM to pre-fill rename suggestions for cryptic identifiers viasampling/createMessage, collapsing the previous review-then-apply flow into a single tool call. Clients without sampling support (e.g. Claude Desktop) silently fall back to the manual review path
OBQC -- Ontology-Based Query Check
A key differentiator of OrionBelt is OBQC (Ontology-Based Query Check), a deterministic, rule-based SQL validator that catches errors before queries reach the database. Unlike LLM-only approaches that rely on the model "getting it right," OBQC cross-references every generated SQL statement against the loaded RDF/OWL ontology to enforce structural correctness.
What OBQC validates:
How it works:
generate_ontologyorload_my_ontologycreates/loads an ontology withoba:namespace annotations that map OWL classes and properties to actual database tables, columns, types, and foreign keys.- When
execute_sql_queryis called, OBQC parses the SQL with sqlglot and validates every table, column, join, and aggregation against the ontology's schema model. - Issues are returned with severity levels (error, warning, info) alongside the query results, so the LLM can self-correct before the user sees wrong data.
OBQC is fully deterministic -- no LLM calls, no probabilistic reasoning. It acts as a safety net that complements the LLM's SQL generation with hard structural guarantees. Errors block query execution; warnings are attached to the response for the LLM to act on. See OBQC documentation for the full rule reference, severity behavior, and annotation requirements.
Quick Start
1. Install
Requires Python 3.13+ and uv.
2. Configure
Edit .env with your database credentials. At minimum, set the variables for one database (e.g. POSTGRES_HOST, POSTGRES_PORT, POSTGRES_DATABASE, POSTGRES_USERNAME, POSTGRES_PASSWORD).
See docs/configuration.md for all environment variables, transport options, and troubleshooting.
3. Run
The server starts on http://localhost:9000 (HTTP transport, configurable via MCP_SERVER_PORT).
Connect Your AI Client
Claude Desktop
Start the server, then add to your claude_desktop_config.json:
Claude Code
LibreChat
Add to librechat.yaml:
Other Frameworks
OrionBelt works with LangChain, OpenAI Agents SDK, CrewAI, Google ADK, Vercel AI SDK, n8n, and ChatGPT Custom GPTs. See docs/integrations.md for setup examples.
Tools
OrionBelt exposes 26 MCP tools. Here is a summary by category:
Connection & Schema
Ontology & Semantic
Query & Visualization
GraphRAG
SPARQL & RDF
Semantic Models
For full parameter details, return values, and examples, see docs/tools-reference.md.
Typical Workflows
Full analysis session:
Quick data exploration:
Query with visualization:
execute_sql_query runs OBQC validation, security checks, and fan-trap detection before executing — no separate validation step is needed.
Resume a previous session (auto-restores workspace):
Development
uv sync installs everything; uv run pytest, black/isort/ruff and strict
mypy are the gates. The Development guide has the full
setup, project layout, and contribution checklist.
One thing worth knowing before you open a workflow file: every GitHub Action is
pinned to a 40-character commit SHA carrying a # vX.Y.Z comment, which is why
they are full of hex. A git tag is a movable label, so actions/checkout@v7 runs
whatever commit that label points at when the job starts; a SHA cannot move. The
comments name exact patch releases rather than # v7, because a major tag moves
with every upstream release. ./scripts/check-action-pins.sh resolves each tag
upstream and fails when the commit it names is not the one pinned -- which is the
only thing that distinguishes a real bump from a hash quietly swapped for one
taken from a fork. It runs as the pins job on every pull request and as the
first step of both publishing workflows; --offline skips the upstream lookups
and checks only the SHA and comment format.
Documentation
License
Copyright 2025-2026 RALFORION d.o.o.
Licensed under the Business Source License 1.1. The Licensed Work will convert to Apache License 2.0 on 2030-03-16.
By contributing to this project, you agree to the Contributor License Agreement.
For commercial licensing inquiries, contact: [email protected]
Third-party software
OrionBelt Analytics builds on open source. THIRD_PARTY_NOTICES.md lists every bundled dependency with its licence, and calls out the few that carry obligations beyond attribution (psycopg2's LGPL, wordfreq's CC-BY-SA data, the MPL-2.0 components).
The Docker image redistributes those packages, so it ships their verbatim licence texts at /app/licenses/THIRD_PARTY_LICENSES.txt, alongside the Debian copyright files under /usr/share/doc/. The PyPI wheel bundles nothing third-party — it declares its dependencies and the installer fetches them from PyPI.
Copyright © 2026 RALFORION d.o.o.
OrionBelt® is a registered trademark of RALFORION d.o.o.
Source: README.md at commit bf65b12
Tools
0Version history
1- v0.5.0LatestSep 16, 2026
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