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ERD Builder Pro
Local MCP access to ERD Builder Pro diagrams, notes, flowcharts and saved database connections
Official · Hadziq JavaScript Local · stdio DatabasesDesign
53 popularity score ★ 207 ↓ 529/wk
Connect your client
Local (npm)
Add in one click
Opens the app, which asks before it adds the server.
Or add it by command or config
Claude CodeTerminal
claude mcp add erd-builder-pro -- npx -y erdbpro mcpClaude Desktopclaude_desktop_config.json
{
"mcpServers": {
"erd-builder-pro": {
"command": "npx",
"args": [
"-y",
"erdbpro",
"mcp"
]
}
}
}Cursor~/.cursor/mcp.json
{
"mcpServers": {
"erd-builder-pro": {
"command": "npx",
"args": [
"-y",
"erdbpro",
"mcp"
]
}
}
}VS Code.vscode/mcp.json
{
"servers": {
"erd-builder-pro": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"erdbpro",
"mcp"
]
}
}
}Codex~/.codex/config.toml
[mcp_servers.erd-builder-pro]
command = "npx"
args = ["-y", "erdbpro", "mcp"]Gemini CLITerminal
gemini mcp add --scope user erd-builder-pro npx -- -y erdbpro mcpSettings 1
ERDBPRO_MCP_USER_ID |
Optional: ID of the local user whose workspace the server opens; needed only when the database holds more than one user. |
|---|
What it does
ERD Builder Pro is a self-hosted workspace for database design: entity-relationship diagrams, flowcharts, rich-text notes, drawings, and a database client for PostgreSQL, MySQL and SQLite. The `erdbpro` npm package starts that workspace as a local web app, and its `erdbpro mcp` subcommand runs a separate MCP server over stdio that works on the same local data in `~/.erdbpro/data.db`. With `--desktop` it opens the data of the installed desktop app instead, without launching its window.
Through the server an assistant can list and search the projects, notes, flowcharts and ERD diagrams in the workspace, read any of them, find the workspace linked to the code repository it is working in, and browse the snapshot history of a document. For the database client it can list the saved connections (without passwords or TLS keys), read a connection's tables, columns, indexes and foreign keys, and run a single SELECT or CTE against a PostgreSQL or MySQL connection in a read-only session.
Only two kinds of change are possible, and both go through a two-step proposal: appending plain text to a note, and restoring an older snapshot of a note, flowchart or diagram. The propose tool returns a preview and a proposal ID; the apply tool needs that ID repeated as confirmation, refuses if the document changed in the meantime, and saves a safety snapshot first. The published bundle (dist-server/mcp.js, version 3.4.7-rc.2) registers 13 tools; the package README mentions the `mcp` command but lists none of them, nor the `ERDBPRO_MCP_USER_ID` setting.
What it needs
| Runtime | Node.js 18+ |
|---|
Node.js 18 or later (22 LTS recommended) on macOS, Linux or Windows. The local workspace must have been opened once with `erdbpro` (or the desktop app, for `--desktop`) so that a local user exists; the MCP server stops with an error otherwise. Database tools need connections already saved in the app's DB Client.
Limits
Diagrams, flowcharts and drawings cannot be created or edited through MCP; the only writes are a note append and a history restore. Drawings are left out of listings. `db_query_read_only` runs one SELECT/CTE per call, only against PostgreSQL or MySQL connections, and returns 100 rows by default, up to 500 with `max_rows`. `workspace_search` returns 20 matches by default, up to 50. The `erdbpro mcp` server reads the CLI's SQLite database only; PostgreSQL storage is for the Docker and desktop builds. If the workspace holds more than one user, `ERDBPRO_MCP_USER_ID` must be set. The latest npm release is a release candidate (3.4.7-rc.2), and the package is licensed PolyForm Noncommercial.
Who it suits
Suits developers who already keep schemas, notes and flowcharts in ERD Builder Pro on their own machine and want a coding assistant to read them, tie them to the repository it is working in, or look up live table structure and run read-only queries on saved PostgreSQL or MySQL connections. It is not a way to have an assistant draw or change ERDs, and it does nothing without an existing ERD Builder Pro workspace; for general database work without that app, a dedicated database server is the plainer choice. The noncommercial licence matters for use at work.