MCP server

isotopo-mcp exposes the agent loop as Model Context Protocol tools over stdio, so Claude Code / Claude Desktop / Cursor / any MCP client can draw isometric diagrams without shelling out to the CLI.

Install

go install github.com/MarkovWangRR/iso-topology/cmd/isotopo-mcp@main

Single static binary, no runtime deps — same as the CLI.

Register

Claude Code:

claude mcp add isotopo -- isotopo-mcp

Claude Desktop / generic MCP client — add to the client’s MCP config (e.g. claude_desktop_config.json):

{
  "mcpServers": {
    "isotopo": {
      "command": "isotopo-mcp"
    }
  }
}

(Use the absolute path from which isotopo-mcp if your client doesn’t inherit $GOPATH/bin on PATH.)

Tools

Tool	Arguments	Returns
`iso_capabilities`	—	the full machine-readable DSL inventory (shapes, primitives, style keys). Call once per session before emitting DSL.
`iso_validate`	`dsl` (required), `format: yaml\|d2\|json`	JSONPath-located issues with `suggest` fixes; `isError: true` when any issue is severity `error`.
`iso_evaluate`	`dsl` (required), `format`	layout scorecard JSON — edge crossings, node overlaps, edge-through-node tunnelling, bends, overall readability score — from three views (`readability`, `iso`, `plan`), plus a `composition` block (balance / alignment / spacing rhythm / aspect / hero dominance / accent-hue discipline, each 0–1 with located findings). Aim for 0 crossings / 0 tunnels, then raise `composition.score` by acting on its findings.
`iso_repair`	`dsl` (required), `format`, `compose: bool`	auto-fixes the DSL and returns the REPAIRED source: label occlusions, node overlaps, low-contrast labels; `compose: true` additionally snaps off-track parts onto neighbours’ alignment tracks (bounded moves, never creates overlaps). Comment-preserving, idempotent — continue the session with the returned `dsl`.
`iso_render`	`dsl` (required), `format`, `output_dir` (optional)	validates first (refuses on errors), then writes `topology.svg`, `topology.html`, source copy, and per-element `nodes/<id>.{svg,yaml}`; returns the file paths. Omitting `output_dir` uses a fresh temp dir.
`iso_snapshot`	`dsl` (required), `format`, `output_dir` (optional)	render + rasterize to a FAITHFUL deterministic `topology.png` (viewport == viewBox, no trim) for visual self-review — LOOK at the image before delivering. Uses resvg / ImageMagick / headless Chrome, whichever is installed.
`iso_preview`	`dsl` (required), `selectors` (required), `format`, `projection: \|top`, `output_dir` (optional)	crops ONE node / group / `edge:N` and returns its SVG markup, so an agent can inspect a single element up close. `projection: top` gives the flat plan view.

The loop, MCP-shaped

iso_capabilities → learn the DSL surface.
Emit YAML following the positioning rules in PROMPT_TEMPLATE.md (or install the draw-iso-diagram skill, which encodes them).
iso_validate → apply suggest values until issues is empty.
iso_evaluate → fix layout until crossings and tunnels are 0, then act on composition.findings (balance / alignment / color) to lift composition.score toward the gallery band (≥ 0.85).
iso_repair (compose: true) → apply the returned dsl — defects and off-track parts fixed in one call, comment-preserved.
iso_render → read back output_dir/topology.svg.
iso_snapshot → LOOK at the PNG before delivering — visual self-review catches what numbers cannot.
iso_preview (optional) → crop a single node or edge to inspect it close up without re-reading the whole scene.

Protocol notes

Minimal, dependency-free implementation: JSON-RPC 2.0 over newline-delimited stdio per the MCP spec. Supported methods: initialize (echoes the client’s protocolVersion), ping, tools/list, tools/call; notifications are accepted and ignored. Resources and prompts are not implemented — the capability surface is deliberately tools-only for now.

Connect an agent

Author reliable diagrams

Install

Register

Tools

The loop, MCP-shaped

Protocol notes

​Install

​Register

​Tools

​The loop, MCP-shaped

​Protocol notes

Install

Register

Tools

The loop, MCP-shaped

Protocol notes