API & MCP

Everything a person can do on Interactive Periodic Table & Property Trends, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

POST https://prooflineperiodictable.usefulweb.app/api/v1/calculate – run Interactive Periodic Table & Property Trends
GET https://prooflineperiodictable.usefulweb.app/api/v1/tool – inputs, output schema, examples
OpenAPI 3.1: /openapi.json · /openapi.yaml
Errors: application/problem+json; 422 includes per-field errors.

Interactive Periodic Table & Property Trends

Colour the periodic table by a property — electronegativity, atomic radius, first ionisation energy, electron affinity, melting and boiling point, density, atomic weight or year of discovery — or by category, block and state. See how the property changes across a period, down a group or along the atomic number, look up one element at a glance or compare up to twelve side by side. Values come from the PubChem periodic table (compiled from NIST, LANL and Jefferson Lab) and the IUPAC standard atomic weights. Part of the Proofline math notebook.

Inputs of Interactive Periodic Table & Property Trends
Field	Type	Default	Description
`property`	select (electronegativity, radius, ionization, affinity, melting, boiling, density, mass, year, category, block, state)	"electronegativity"	Property
`elements`	text	—	Elements to look up (optional). Symbols, names or atomic numbers separated by commas; one element shows its card, several (at most 12) a comparison table.
`trend`	select (atomic-number, period, group)	"atomic-number"	Trend
`index`	integer	—	Period or group number. For a period trend 1–7, for a group trend 1–18. Empty: the period or group of the first element looked up.
`scale`	select (auto, linear, log)	"auto"	Colour scale

Example request

Electronegativity across period 2, with fluorine

curl -X POST https://prooflineperiodictable.usefulweb.app/api/v1/calculate -H 'content-type: application/json' -d '{"property":"electronegativity","elements":"F","trend":"period","index":2}'

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

Streamable HTTP endpoint: https://prooflineperiodictable.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
Tools: proofline_periodic_table
Local stdio connector: node src/mcp-stdio.ts --tool=proofline-periodic-table

{
  "mcpServers": {
    "proofline-periodic-table": { "type": "http", "url": "https://prooflineperiodictable.usefulweb.app/mcp" }
  }
}