Merovingian

Cross-repository dependency intelligence for AI agents via MCP.

Merovingian maps cross-repo dependencies — API contracts, shared schemas, consumer relationships — and detects breaking changes before they propagate. It answers: "What else will break if I change this?"

Part of the EvoIntel MCP Suite (Sentinel, Niobe, Merovingian, Seraph, Anno).

Features

• OpenAPI spec parsing — detects endpoints, request/response schemas, $ref resolution (recursive, with cycle detection), allOf/anyOf/oneOf support

• Pydantic model extraction — AST-parses Python files for BaseModel subclasses, no runtime imports needed

• Direction-aware breaking change detection — request vs response changes have opposite breaking semantics

• Consumer registry — track which services consume which endpoints

• Dependency graph — visualize producer/consumer relationships across repos

• Contract versioning — deterministic SHA256 spec hashing, version history with diff tracking

• MCP interface — 8 tools for AI agent consumption

• CLI — 12 commands via Typer with Rich output

Related MCP server: SGraph MCP Server

Installation

pip install merovingian

Quick Start

# Register repositories
merovingian register user-service /path/to/user-service --type openapi
merovingian register billing-service /path/to/billing-service

# Scan for contracts
merovingian scan user-service

# Register consumer relationships
merovingian add-consumer billing-service user-service GET /users/{id}

# Check for breaking changes
merovingian breaking user-service

# Full impact assessment with consumer mapping
merovingian impact user-service

# View dependency graph
merovingian graph

# Contract version history
merovingian contracts user-service

CLI Commands

MCP Server

Add to your Claude Code configuration (~/.claude.json):

{
  "mcpServers": {
    "merovingian": {
      "command": "merovingian-mcp",
      "args": []
    }
  }
}

MCP Tools

Breaking Change Detection

Merovingian classifies changes with direction-aware logic:

Breaking (blocks consumers):

• Endpoint removed

• Required field added to request body

• Response field removed

• Field type changed (non-widening)

• Optional field made required in request

Warning:

• Type widened (e.g., integer → number)

• Required field made optional in response

Info (non-breaking):

• Endpoint added

• Optional field added to request

• Response field added

• Summary/description changed

Configuration

Merovingian uses layered configuration: TOML file → environment variables → defaults.

Create .merovingian/config.toml in your project root:

[store]
db_name = "merovingian.db"

[scanner]
openapi_patterns = ["openapi.yaml", "openapi.json", "swagger.yaml", "swagger.json"]
pydantic_scan_dirs = ["src", "app", "lib"]

[mcp]
default_query_limit = 50

Part of the EvoIntel MCP Suite

Merovingian solves AI Blindness #3: Cross-Service Dependencies — API contracts, consumer relationships, and breaking changes that span repository boundaries.

Part of the EvoIntel MCP Suite by Evolving Intelligence AI: five tools for five blindnesses no model improvement will ever fix.

License

MIT