Erd Editor vs OSCAR
A side-by-side look at the Erd Editor and OSCAR MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Erd Editor for developer tools work as a local process; choose OSCAR for developer tools as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Erd Editor when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
- You want tools like
erd_list_documents, erd_open_document, erd_save.
Choose OSCAR when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
- You want tools like
status, list_projects, read_project.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Developer Tools | Developer Tools |
| Quality signal | 71/100 · Great | 64/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | No auth required | No auth required |
| Pricing | Free | Free |
| Required env vars | None listed | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 1,729 | 192 |
| Directory activity | 0 views 0 installs 0 upvotes | 0 views 0 installs 0 upvotes |
| Tools | 77 | 11 |
| Full listing | View Erd Editor | View OSCAR |
Tools & capabilities
Erd Editor tools 77
erd_list_documentsLists ERD documents with path, open, active, dirty and readonly. With an editor serving the working directory (the VS Code extension, the Obsidian plugin or the JetBrains IDE plugin) it lists that editor's, every open project's in a JetBrains IDE; otherwise the ERD files under the working directory.erd_open_documentOpens a document for editing, in the ERD editor of the editor that serves it, if one does (the VS Code extension, the Obsidian plugin or the JetBrains IDE plugin). With create it makes the file first if missing; a name with no extension gets .erd.json.erd_saveSaves a document an editor holds to disk. VS Code keeps edits unsaved until this is called; Obsidian and JetBrains IDEs save them as they save the user’s edits, and this writes them at once. On disk, with no editor, edits are written at once and this does nothing.erd_undoReverts the last edit this agent made to the document, never the user’s edits. Calls that made no undo entry are skipped and named.erd_redoApplies again the edit erd_undo last reverted.erd_readReads a document as a snapshot, as DDL, as its raw JSON or, with the scripts format, its before and after scripts alone. The sql format of the whole document includes the document's before and after scripts. The sql format with tableIds, tableNames or groupNames gives the DDL of just those tables, the way to read a large schema; a read too large for one answer is refused with how to narrow it. For ids and details prefer erd_list and erd_get. Change a document only through the erd_ tools, never by writing its file.erd_listLists a document: its settings and counts, then a page of tables, each with its id, position and size on the ERD canvas (the width approximate, the height exact), with their indexes and relationships (each relationship once, with one of its tables) and, for a table in a table group or with a logical name, its groupId or logicalName; after the tables come the table groups, the memos, then the rows of the domain, term and word dictionaries, each with its name and what it gives a physical name or column. A small schema fits in one page. On a larger one, nextOffset and note say how to go on: query finds tables by a word, namesOnly lists every table name in a call or a few. Columns, comments, memo text, the tables of a group and every field of a dictionary row come from erd_get; the foreign keys a table holds, from erd_read sql with tableNames.erd_getGives the entities named, in full: tables with their columns and size, relationships with their columns, indexes with their columns, memos with their text, table groups with their tables, and words, terms and domains with every field. Ids and names that name nothing live are listed in missing; ids one answer has no room for are listed in notReturned, to ask for again.erd_list_checksLists what the word, term and domain dictionaries find, as the Checks sheet of the editor's Dictionary tab does, and changes nothing. Errors: a name two rows of one dictionary share, a link to a domain the document does not list, a forbidden word in a logical name or a term's name. Warnings: a word no dictionary lists, a synonym used for a standard word, each in a logical name or a term's name, a physical name other than the one the term of its logical name gives, a column type other than its domain's. Each check names its target (a table, a column with its table, or a word, term or domain row) with its names, the field read, the text found and, where the dictionaries have them, the suggestions to use instead, and counts gives each code's total. The words, terms and domains come first in sheet order, then each table and its columns in document order. With no dictionary row nothing is checked. A long list comes a page at a time: pass nextOffset, or list again from offset 0 after fixing some, since a fixed check leaves the list.erd_add_tableAdds an empty table at a free spot and returns its id in createdIds. Name it with erd_change_table_name.erd_remove_tableRemoves a table with its columns, indexes and every relationship that touches it.erd_change_table_nameRenames a table. The name is then its own: nameDerived goes off, so a later logical name leaves a name that is not empty as it is.- +65 more on the listing page
OSCAR tools 11
statusOSCAR's version, its ports (HTTP, the fixed OSC listening port, the socket bridge), whether editing is locked, the MIDI driver's condition, and how many projects and published interfaces there are. Start here.list_projectsEvery project OSCAR holds, with its id and its title, as File > Open project or template lists them. A project is what a person edits; it reaches phones only once it is published (list_published).read_projectEvery widget in one project, published or not, with its full settings as the editor holds them: addresses, ports, channels, MIDI mappings, DMX targets. Also says where the project is published, if it is. A setting nobody touched reads as its default. What phones see is the published copy, which may be older: read_published reads that one.list_publishedEvery published interface: its name, the project it was published from, the path it is served at, who can open it (access: "network", or "off" for one no device can open, whose schedules and bridges still run), and how many widgets it holds. Published interfaces are running -- phones and tablets may be on them, and the rig hears them.read_publishedEvery widget on one published interface, with its full settings as phones have them: addresses, ports, channels, MIDI mappings, DMX targets. For answering why something does or does not respond.installation_mapOne picture of the whole installation: this computer's network addresses and ports, its MIDI ports and USB interfaces (a USB DMX interface among them), and everything the published interfaces talk to and listen for -- each OSC destination with the addresses sent to it, each MIDI port with its channels and controllers, each DMX output with its universe and channels -- with the control and interface behind every one. notices lists what does not add up: a MIDI port or USB interface that is not there, OSC followed while OSCAR cannot listen, two controls on the same DMX channels. It is worked out from settings and sends nothing onto the network: it says where OSCAR sends, not whether anything is there to hear it.midi_portsThe MIDI inputs and outputs this machine has right now, and the driver's condition.recent_activityThe network log's recent rows: what OSCAR's server actually received and sent, oldest first, repeats within a moment gathered into one row with a count n. Each row has what (OSC address, MIDI control, DMX universe and channels) and value (what the latest carried). Incoming rows: device (the sender's address, or the MIDI port), surfaces (published interfaces that follow it), canvas (the editor's canvas followed it); with neither, nothing follows it. Outgoing rows: to (where it went), origin (whose move: canvas, local, internet, schedule, bridge), surface (the published interface) and widget. dropped, on either, says why it was refused. The first place to look when something moves that should not, or does not move when it should.describe_widgetsEvery widget OSCAR has -- tag, attributes, defaults, and each setting with its type, options and meaning -- plus how an interface is written as HTML. Read this before building one.validate_draftRun an interface written as HTML through the widgets' own validators: unknown settings, values their panels would refuse, missing or repeated ids. Returns the complaints to correct. Nothing is saved.create_draftValidate an interface and, if it is clean, save it as a draft: it appears in OSCAR under File > Open project or template, with a Draft badge. It is a file for a person to review: nothing is published, nothing is sent, and no project is changed. An existing draft of the same name is only replaced when overwrite is true.
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Erd Editor
{
"mcpServers": {
"erd-editor": {
"command": "npx",
"args": [
"-y",
"@dineug/erd-editor-mcp"
]
}
}
}
OSCAR
{
"mcpServers": {
"oscar": {
"command": "npx",
"args": [
"-y",
"createwithoscar"
]
}
}
}
Frequently asked questions
Erd Editor is categorized under Developer Tools and uses a local stdio subprocess. OSCAR belongs to Developer Tools and uses a local stdio subprocess. Pick Erd Editor for developer tools work and OSCAR for developer tools.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Erd Editor is listed as free. Auth: no auth required. OSCAR is listed as free. Auth: no auth required. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add erd-editor and oscar as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Erd Editor has a quality signal of 71/100 (Great) with 0 views, 0 installs and 1,729 GitHub stars. OSCAR has 64/100 (Good) with 0 views, 0 installs and 192 GitHub stars.