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Equation.io

by equation.io · remote · no sign-in to list tools · v1.0.1 · published by io.equation

Create interactive 2D and 3D graphs with validated equations, shareable links, and PNG previews.

Changes · 2
CompareRegistry entry

3 tools: 2 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http equation https://equation.io/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

3 tools

Changes things 2Claude Code: ask
  • decode_graph_urlDecode an equation.io link (either the #-fragment form or the /g/ share form) into its list of equation rows, so you can edit them and build a new link with encode_graph_url.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Decode an equation.io link (either the #-fragment form or the /g/ share form) into its list of equation rows, so you can edit them and build a new link with encode_graph_url. The rows use the equation.io syntax documented in the "syntax" MCP resource (also at https://equation.io/llms.txt).

    Annotations the server declares

    • title: Read a graph link
    • readOnlyHint: true
    • openWorldHint: false
    • destructiveHint: false
    • idempotentHint: true
  • encode_graph_urlBuild an equation.io graph link, validating every row with the app's parser.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Build an equation.io graph link, validating every row with the app's parser. Pass the COMPLETE graph in "equations": a flat array of strings, one equation or definition per string, in display order — when editing an existing graph (see decode_graph_url), include unchanged rows too. Rows can be: equations and inequalities in x,y (curves, regions; z makes it 3D), bare expressions in x, y (scalar fields — a curve is written y = f(x); complex plots via w), points (rows report "draggable"), parametric tuples in u,v — and definitions: "a = 2" (a draggable slider), "f(x) = x^3 - a x", coordinate fields like "r = sqrt(x^2+y^2)" for polar. t animates. Also derivatives d/dx, integrals int[a..b] f dx, sums sum[n=1..N], domain()/conformal()/iter() for complex plots, rgb()/hsl()/oklch() color fields, y' = … slope fields, random variables "X ~ Normal(m, s)"/"P(0<X<2)"/"E(X^2)", and "view(x = -5..5, y = -2..2)"/"camera(theta, phi)" framing rows. That is a menu, not the syntax: before your first non-trivial graph, read the "syntax" MCP resource (also at https://equation.io/llms.txt). The result returns text and structured data only. "rows" gives each equation's validation result: status "ok" with its kind, or "error" with the parser message. The link is usable only once every row is "ok". Give users the share_url (it unfurls to a link card in chat apps); url is the equivalent #-fragment form. No image is attached to the tool response.

    Annotations the server declares

    • title: Create a graph link
    • readOnlyHint: true
    • openWorldHint: false
    • destructiveHint: false
    • idempotentHint: true
Only reads 1Claude Code: allow
  • show_graphDisplay an interactive equation.io graph inside the conversation, with editable equations, sliders, pan/zoom, and 3D rotation.No findings

    Why it is in this group

    • The name "show_graph" says "show": a word for reading.
    Description, as the server wrote it
    Display an interactive equation.io graph inside the conversation, with editable equations, sliders, pan/zoom, and 3D rotation. Use when the user asks to see or explore a graph. Pass the COMPLETE graph as "equations", one equation or definition per string, preserving unchanged rows when editing. For a slider use "a = 2" then "y = a sin(x)". For advanced syntax read the "syntax" resource (https://equation.io/llms.txt). Returns per-row validation and share links; a row with status "error" is not drawn until its text is corrected and the graph resubmitted. Use encode_graph_url for validation or link-only requests (including share-link preview notes). In clients without UI support, provide share_url.

    Annotations the server declares

    • title: Show an interactive graph
    • readOnlyHint: true
    • openWorldHint: false
    • destructiveHint: false
    • idempotentHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.1. Values in angle brackets are yours to fill in.

claude mcp add --transport http equation https://equation.io/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__equation__show_graph"
    ],
    "ask": [
      "mcp__equation__encode_graph_url",
      "mcp__equation__decode_graph_url"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as equation. Review it before you use it.