Chempirical

Chempirical (operated as Nitramine per the submission) publishes free tools for chemists and a free, keyless, read-only JSON API at chempirical.com/api covering compounds (names, formula, SMILES/InChI identifiers, molar mass, density, melting and boiling points, Antoine constants, azeotropes), substructure and similarity search, structure SVGs, reactions with participants and reaction scaling. CORS is open; the docs ask for a few requests per second.

Chempirical is listed with 4 APIs on the APIs.io network, including Chempirical (Nitramine) API, Molecule Svg API, Molecules API, and 1 more. Tagged areas include Company, Chemistry, Compounds, Reactions, and Science.

The Chempirical catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Chempirical’s developer surface includes documentation, engineering blog, and 12 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

23.4/100 emerging ▬ flat Agent 19/100 agent aware Heartbeat 26/100 dormant Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFree

4 APIs

Company Chemistry Compounds Reactions Science Open Data JSON:API

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 23.4/100 · emerging

Contract Quality 3.9 / 19

Developer Ergonomics 0.9 / 15

Access Clarity 4.1 / 15

Operational Transparency 2.1 / 10

Contract Governance 2.0 / 9

Discoverability 5.4 / 8

Regulatory Posture 1.6 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 19/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 0 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Government & Public Sector regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 21.0 — up to +19.8 composite points
Developer Ergonomics scores 6.0 — up to +18.8 composite points
Access Clarity scores 27.6 — up to +14.5 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/chempirical/apis.yml: open an issue on github.com/api-evangelist/chempirical to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

JSON:API

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

OpenAPI

measured — observed by APIs.io (published)

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

Chempirical Chempirical (Nitramine) API

The Chempirical (Nitramine) API API from Chempirical — 1 operation(s) for chempirical (nitramine) api.

Chempirical Molecule Svg API

The Molecule Svg API from Chempirical — 1 operation(s) for molecule svg.

Chempirical Molecules API

The Molecules API from Chempirical — 1 operation(s) for molecules.

Chempirical Reactions API

The Reactions API from Chempirical — 2 operation(s) for reactions.

Chempirical API pricing

Prices published by Chempirical.

Plan	Price
Free JSON API	No key, no sign-up.

Plan details, limits and sources →

Rate limits

Courtesy request rate: Please keep it to a few requests per second.

Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Chempirical Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Chempirical Rate Limits

1 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Chempirical

SLA

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Chempirical Context

7 classes · 9 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Chempirical API Rules

11 rules · 9 errors 1 warnings 1 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

GetApiApiidResponse

1 properties

JSON SCHEMA

GetApiMoleculeSvg50782Response

1 properties

JSON SCHEMA

GetApiMoleculesMoleculeidResponse

3 properties

JSON SCHEMA

GetApiReactionsHenryNitroaldolResponse

1 properties

JSON SCHEMA

GetApiReactionsHenryNitroaldolScaleResponse

1 properties

JSON SCHEMA

PostApiMoleculesMoleculeidResponse

3 properties

JSON SCHEMA

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Chempirical Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

Login

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conventions

Conformance

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 1

Pricing, plans, and the legal terms of use

Plans

Plans

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Hosts

Hosts

Source (apis.yml)

aid: chempirical
name: Chempirical
accessModel:
  pricing: free
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Free
  confidence: medium
  probe_state: unreadable
  source:
  - plans
  - rate-limits
  - security
  generated: '2026-11-06'
  method: derived
image: https://chempirical.com/og-image.png
description: Chempirical (operated as Nitramine per the submission) publishes free tools for chemists and a free, keyless,
  read-only JSON API at chempirical.com/api covering compounds (names, formula, SMILES/InChI identifiers, molar mass, density,
  melting and boiling points, Antoine constants, azeotropes), substructure and similarity search, structure SVGs, reactions
  with participants and reaction scaling. CORS is open; the docs ask for a few requests per second.
url: https://raw.githubusercontent.com/api-evangelist/chempirical/refs/heads/main/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-09 (local-v5; was harvest)
specificationVersion: '0.20'
created: '2026-10-09'
modified: '2026-10-09'
tags:
- Company
- Chemistry
- Compounds
- Reactions
- Science
- Open Data
- JSON:API
tags_raw:
- Company
- Chemistry
- Compounds
- Reactions
- Science
- Open Data
- JSON API
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: RateLimits
  url: rate-limits/chempirical-rate-limits.yml
- type: Plans
  url: plans/chempirical-plans-pricing.yml
- type: Spectral
  url: rules/chempirical-rules.yml
- type: JSONLD
  url: json-ld/chempirical-context.jsonld
- type: Vocabulary
  url: vocabulary/chempirical-vocabulary.yml
- type: DataModel
  url: data-model/chempirical-data-model.yml
- type: Conventions
  url: conventions/chempirical-conventions.yml
- type: Conformance
  url: conformance/chempirical-conformance.yml
- type: Hosts
  url: hosts/chempirical-hosts.yml
- type: DomainSecurity
  url: security/chempirical-domain-security.yml
- type: Website
  url: https://chempirical.com
- type: Documentation
  url: https://chempirical.com/api/
- type: Blog
  url: https://chempirical.com/blog/
- type: Login
  url: https://chempirical.com/auth/login
apis:
- aid: chempirical:chempirical-chempirical-nitramine-api-api
  name: Chempirical Chempirical (Nitramine) API
  description: The Chempirical (Nitramine) API API from Chempirical — 1 operation(s) for chempirical (nitramine) api.
  humanURL: https://chempirical.com/api/
  baseURL: https://chempirical.com/api
  tags:
  - Chempirical (Nitramine) API
  properties:
  - type: OpenAPI
    url: openapi/chempirical-chempirical-nitramine-api-api-openapi.yml
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-apiid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-scale-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-post-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecule-svg50782-response-schema.json
- aid: chempirical:chempirical-molecule-svg-api
  name: Chempirical Molecule Svg API
  description: The Molecule Svg API from Chempirical — 1 operation(s) for molecule svg.
  humanURL: https://chempirical.com/api/
  baseURL: https://chempirical.com/api
  tags:
  - Molecule Svg
  properties:
  - type: OpenAPI
    url: openapi/chempirical-molecule-svg-api-openapi.yml
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-apiid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-scale-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-post-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecule-svg50782-response-schema.json
- aid: chempirical:chempirical-molecules-api
  name: Chempirical Molecules API
  description: The Molecules API from Chempirical — 1 operation(s) for molecules.
  humanURL: https://chempirical.com/api/
  baseURL: https://chempirical.com/api
  tags:
  - Molecules
  properties:
  - type: OpenAPI
    url: openapi/chempirical-molecules-api-openapi.yml
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-apiid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-scale-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-post-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecule-svg50782-response-schema.json
- aid: chempirical:chempirical-reactions-api
  name: Chempirical Reactions API
  description: The Reactions API from Chempirical — 2 operation(s) for reactions.
  humanURL: https://chempirical.com/api/
  baseURL: https://chempirical.com/api
  tags:
  - Reactions
  properties:
  - type: OpenAPI
    url: openapi/chempirical-reactions-api-openapi.yml
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-apiid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-reactions-henry-nitroaldol-scale-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-post-api-molecules-moleculeid-response-schema.json
  - type: JSONSchema
    url: json-schema/chempirical-get-api-molecule-svg50782-response-schema.json
x-submission-notes: Free keyless chemistry JSON API (compounds, reactions)
x-submission-probe: /api/ 200 HTML docs; /openapi.json and /api/openapi.json 404 (no contract found); invented path 404
x-submitted-by: marty@chempirical.com (apis.io/add, 2026-10-09)
x-coverage:
  state: unreadable
  reason: no-machine-readable-spec
  method: derived
  generated: '2026-10-09'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company publishes developer documentation but serves no machine-readable contract from it
  evidence:
  - url: https://chempirical.com
    status: 200
x-enrichment:
  date: '2026-10-09'
  status: enriched
  artifacts_added: 14
  pass: local-v5

Chempirical API — frequently asked questions

Does Chempirical have an API?

Yes. APIs.io lists 4 APIs from Chempirical, including Chempirical Chempirical (Nitramine) API, Chempirical Molecule Svg API and Chempirical Molecules API, and 1 more.

Is there an OpenAPI specification for the Chempirical API?

Yes. APIs.io indexes 4 OpenAPI specifications for Chempirical, each linked for download from this page.

How much does the Chempirical API cost?

Chempirical publishes its prices; its Free JSON API plan is No key, no sign-up. as of 2026-10-09. APIs.io lists 1 pricing plan for Chempirical, with each plan's price, limits and inclusions under Pricing on this page.

Is the Chempirical API ready for AI agents?

Chempirical has a Kin Score of 23.4 out of 100 (emerging) and an Agent Readiness score of 19.0 (agent-aware), scored by API Evangelist on 2026-11-06.

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