Local Development

Prerequisites

Node.js (for wrangler dev server)
Cloudflare account with Workers + KV enabled
Two TTF fonts uploaded to KV (see Configuration page)

Install

git clone https://github.com/lingion/plot-mcp-worker
cd plot-mcp-worker
npm install    # installs wrangler, typescript, expr-eval, opentype.js, resvg-wasm

Locked deps in package-lock.json; npm ci also works.

Scripts (from `package.json`)

npm script	Command	Purpose
`dev`	`wrangler dev`	Local Worker dev server (Miniflare under the hood)
`deploy`	`wrangler deploy`	Push to Cloudflare Workers
`check`	`tsc --noEmit`	TypeScript type-check only (no emit)
`test:smoke`	`node scripts/smoke.mjs`	Hit /healthz and a few tool calls
`probe:force-analysis`	`node scripts/local-force-analysis-probe.mjs`	Generate 8 force-analysis samples locally
`check:force-drift`	`node scripts/force-analysis-drift-check.mjs`	Compare local vs deployed SVG byte hash
`check:force-struct`	`node scripts/force-analysis-struct-diff.mjs`	Diff structure of local vs deployed SVG
`check:force-compact`	`node scripts/force-analysis-compact-diagnose.mjs`	Compact diagnose of force analysis output
`check:force-verify`	`node scripts/force-analysis-verify.mjs`	Full verification of force analysis
`check:bundle-fingerprint`	`node scripts/deploy-bundle-fingerprint.mjs`	Fingerprint the deployed worker bundle
`check:deploy-preflight`	`node scripts/deploy-preflight.mjs`	Pre-deploy sanity checks
`check:deploy-and-verify`	`node scripts/deploy-and-verify.mjs`	Deploy then immediately verify
`check:remote-health`	`node scripts/remote-health.mjs`	Hit deployed `/healthz` and parse JSON

Typical workflow

# 1. Type-check
npm run check

# 2. Smoke test against local dev server (needs wrangler dev running in another terminal)
npm run dev   # in terminal 1
npm run test:smoke  # in terminal 2

# 3. Verify force analysis output before deploying
npm run probe:force-analysis
npm run check:force-drift

# 4. Deploy
npm run deploy

# 5. Verify deployed
npm run check:remote-health

Calling the MCP endpoint from curl

# initialize
curl -s -X POST https://your-worker.workers.dev/mcp   -H "Content-Type: application/json"   -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}'

# tools/list
curl -s -X POST https://your-worker.workers.dev/mcp   -H "Content-Type: application/json"   -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

# tools/call -&gt; plot
curl -s -X POST https://your-worker.workers.dev/mcp   -H "Content-Type: application/json"   -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"plot","arguments":{"expr":"sin(x)","x_min":-6.28,"x_max":6.28,"title":"Sine","render":{"format":"link"}}}}'

Calling web endpoints

The web endpoints (/plot, /png, etc.) take a ?d= query parameter with gzipped base64url JSON. Easiest path: use the MCP tool (which returns the URL), or generate the encoded payload in Node:

import { toCompressedBase64UrlFromJson } from "./src/utils.js";
const d = await toCompressedBase64UrlFromJson({
  expr: "sin(x)", x_min: -6.28, x_max: 6.28, points: 1000,
  title: "Sine", xlabel: "x", ylabel: "y"
});
console.log("https://your-worker.workers.dev/plot?d=" + d);