Materials Project
The Materials Project API provides direct access to the Materials Project database, a large-scale computational materials science database with data on tens of thousands of materials. The API is offered free of charge and supports machine learning, automated analysis, and bulk data downloads.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles Materials Project the way a machine reads it — 36 machine-readable artifacts across 29 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Materials Project scores 40.6/100 (thin), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Materials Project
Each block below is one kind of artifact we hold for Materials Project. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 29
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Materials Project Defect Tasks API
The Defect Tasks API from Materials Project — 1 operation(s) for defect tasks.
Materials Project DOIs API
Route providing DOI and bibtex reference information for a material. Note that this data may not be available for all materials in the Materials Project database. See the `DOIDo...
Materials Project JCESR Electrolyte Genome API
Route providing computed data for a legacy molecule such as charge, electron affinity, and ionization energy. The unique identifier for a molecule is its `task_id` (e.g. `mol-45...
Materials Project Materials Absorption API
The Materials Absorption API from Materials Project — 1 operation(s) for materials absorption.
Materials Project Materials Alloys API
Route for retrevial of information about which hypothetical alloy(s) a given material might belong to, following the methodolgy discussed by [Woods-Robinson, Horton and Persson]...
Materials Project Materials API
Route for "core" information associated with a given material in the Materials Project database. The unique identifier for a material is its `material_id` (e.g. `mp-149`). Core ...
Materials Project Materials Bonds API
Route for retrevial of bonding information for a given material.
Materials Project Materials Chemical Environment API
The Materials Chemical Environment API from Materials Project — 1 operation(s) for materials chemical environment.
Materials Project Materials Dielectric API
Route providing computed dielectric data for a material following the methodology discussed by [Petousis *et al.*](https://doi.org/10.1038/sdata.2016.134) Note that dielectric d...
Materials Project Materials Elasticity API
Route providing computed elasticity data for a material following the methodology discussed by [de Jong *et al.*](https://doi.org/10.1038/sdata.2015.9) Note that elasticity data...
Materials Project Materials Electrodes API
Route providing computed electrode data for a material following the methodology discussed by [Shen *et al.*](https://doi.org/10.1038/s41524-020-00422-3) Note that electrode dat...
Materials Project Materials Electronic Structure API
Routes providing computed electronic structure related data for a material such as band gap and fermi level. Python objects for line-mode band structures, density of states, and...
Materials Project Materials EOS API
Route providing computed equations of state data for a material following the methodology discussed by [Latimer *et al.*](https://doi.org/10.1038/s41524-018-0091-x) Note that eq...
Materials Project Materials Grain Boundaries API
Route providing computed grain boundary data for a material following the methodology discussed by [Hui *et al.*](https://doi.org/10.1016/j.actamat.2019.12.030) Note that grain ...
Materials Project Materials Magnetism API
Route providing computed magnetic ordering related data for a material following the methodology discussed by [Horton *et al.*](https://doi.org/10.1038/s41524-019-0199-7) Note t...
Materials Project Materials Oxidation States API
Route providing computed oxidation state data for a material following the methodology employed by the [BVAnalyzer](https://pymatgen.org/pymatgen.analysis.bond_valence.html) in ...
Materials Project Materials Phonon API
**Under construction** Route providing computed phonon data for a material following the methodology discussed by [Petretto *et al.*](https://doi.org/10.1038/sdata.2018.65) Note...
Materials Project Materials Piezoelectric API
Route providing computed piezoelectric data for a material following the methodology discussed by [de Jong *et al.*](https://doi.org/10.1038/sdata.2015.53) Note that piezoelectr...
Materials Project Materials Provenance API
Route providing provenance data for a material such as whether it is theoretical, its associated ICSD entries, and relevant references in literature. Note that provenance data m...
Materials Project Materials Robocrystallographer API
Route providing a computed text description for a material following the methodology discussed by [Ganose *et al.*](https://doi.org/10.1557/mrc.2019.94) Note that descriptions m...
Materials Project Materials Similarity API
Route providing a computed similarity metric between materials following the methodology discussed by Zimmerman *et al.* in [10.3389/fmats.2017.00034](https://doi.org/10.3389/fm...
Materials Project Materials Substrates API
Route providing computed suggested substrate data for a material following the methodology discussed by [Ding *et al.*](https://doi.org/10.1021/acsami.6b01630) Note that substra...
Materials Project Materials Summary API
Route providing a large amount of amalgamated data for a material. This is constructed by combining subsets of data from many of the other API endpoints. The summary endpoint is...
Materials Project Materials Surface Properties API
Route providing computed surface property data for a material following the methodology discussed by [Tran *et al.*](https://doi.org/10.1038/sdata.2016.80) Note that surface dat...
Materials Project Materials Synthesis API
Route providing a synthesis recipes for materials extracted from literature following the methodology discussed by [Kononova *et al.*](https://doi.org/10.1038/s41597-019-0224-1)...
Materials Project Materials Tasks API
Route for "core" information associated with a given calculation in the Materials Project database. Multiple calculations can ultimately be associated with a unique material, an...
Materials Project Materials Thermo API
Route providing computed thermodynamic data for a material such as formation energy and energy above hull. Corrected energy values are also available that employ the schemes dis...
Materials Project Materials XAS API
Route providing computed x-ray absorption spectroscopy data for a material following the methodology discussed by [Mathew *et al.*](https://doi.org/10.1038/sdata.2018.151) and [...
Materials Project Molecules Summary API
Route for a summary of all data calculated on 'core' molecules in the Materials Project molecules database. See the `MoleculeSummaryDoc` schema for a full list of fields returne...
Scroll within the panel for all 29 ·
Open Collections 1
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Materials Project API
OPEN COLLECTIONPricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Materials Project Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Materials Project Finops
FINOPSSecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for Materials Project — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 2
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 2
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
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