KG-SSOT

A verifiable knowledge graph: every claim says where it came from, when it was verified, and what depends on it. Your CI rejects the claims that don't.

This package ships the formal KG-SSOT contract and the tools that enforce it:

• the reference reader, which checks a .kg.yaml or .kg.json graph against the contract at two levels: MUST, which fails, and SHOULD, which warns;
• the conformance suite, as plain data, that every reader must pass;
• the per-graph gate for CI, with a ratchet: existing debt stays named and can't get worse;
• the store, which only writes what passes the contract;
• the reference MCP server, which gives a model the contract and the store over stdio or local HTTP;
• the domain vocabulary, with the source and verification date of each synonym, exported to SKOS-XL and Apache Ossie;
• the provenance exporter to PROV-O in JSON-LD.

The contract, the suite, and the verdict schema ship inside the package. The reader depends on no agent harness. It needs Python 3.11 or later, PyYAML, and jsonschema.

Install

pip install kg-ssot

To run the commands without installing them into your environment, use pipx install kg-ssot or uvx --from kg-ssot kg-validate.

Quickstart

Check your graphs against the current contract:

kg-validate graph.kg.yaml other.kg.json

PASS graph.kg.yaml
FAIL other.kg.json
  MUST   form.range.node.impact ×1 · integrity.orphan-node ×1
· 2 files; 1 pass the MUST; 0 with a SHOULD warning (kg-contract-v4.schema.json + kg-contract-v4.should.schema.json)

The exit code is 0 when every file passes the MUST, 1 when any file fails, and 2 on broken input. Two useful modes:

• kg-validate --where shows the node or edge of each occurrence and, for a MUST occurrence that has a canonical fix, the fix right below it;
• kg-validate --format json returns the structured verdict (code, path, line, message, and hint) in the versioned kg-ssot.verdict/1 format.

Run the bundled conformance suite against the reference reader:

kg-conformance | tail -2

latest: 438/438 (gates the rc)
optional: 10/24 (report only)

Only latest/ sets the exit code. The optional/ cases are reported and never change it.

Commands

As a library, the modules live under kg_ssot: kg_ssot.kg_validate, kg_ssot.kg_store, kg_ssot.kg_mcp, and the rest.

MCP server

kg-mcp --root ./graphs --init
uvx kg-ssot --root ./graphs --init   # the same server, no install: kg-ssot is an alias for kg-mcp

The server speaks MCP over stdio. With --http PORT, it serves HTTP on loopback (127.0.0.1) by default, with no TLS. To listen beyond loopback, you need --allow-remote plus a shared secret (--secret-env), and you still put a proxy that handles TLS in front of it.

Package or vendor

Use the package to run the reader as a library, a command, or an MCP server. For the gate in a repository's CI, the recommended channel is still vendoring by tag: kg_vendor.py brings the release into your repository and verifies the sha256 of every file. That way, the contract that judges your graph shows up in your diff. The adoption guide covers both paths.

Documentation

• Manual: the format, the contract, the tools, adoption, and troubleshooting
• Adoption guide
• Conformance suite
• For AI agents (llms.txt)
• Source and releases

License

Apache-2.0. See LICENSE and NOTICE.

Documentação em português: README.pt-BR.