Numeral

Numeral (Numeral HQ) is a sales-tax compliance and automation platform for ecommerce and SaaS companies. Its REST API calculates real-time sales tax by customer location at state, county, city, and district granularity, records transactions and refunds, and manages products and customers, while the broader platform handles registrations, nexus monitoring, filing, and remittance. Not to be confused with Numeral (numeral.io), an unrelated payment-operations company now part of Mambu.

Numeral publishes 6 APIs on the APIs.io network, including Customers API, Health API, Products API, and 3 more. Tagged areas include Sales Tax, Tax Compliance, Tax Calculation, Ecommerce, and SaaS.

Numeral’s developer surface includes authentication, documentation, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub
36.6/100 thin ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemiumSelf serve⚡ Free to try
9 APIs
Sales TaxTax ComplianceTax CalculationEcommerceSaaS

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 36.6/100 · thin
Contract Quality 14.0 / 25
Developer Ergonomics 3.9 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 3.4 / 13
Governance 0.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 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
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/numeral: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 9

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

Numeral Filings API

Sales-tax return filing and remittance (Autofile) across all US states, driven by recorded transactions. Filing and remittance are delivered as managed platform services rather ...

Numeral Registrations & Nexus API

State sales-tax registration (Autoregister) and physical/economic nexus monitoring with state-crossing alerts. Provided as managed platform services on top of API-captured trans...

Numeral Webhooks

Event notifications for compliance and transaction lifecycle changes (e.g., filing, registration, and nexus events). Webhook delivery is offered through the Numeral platform; no...

Numeral Customers API

The Customers API from Numeral — 2 operation(s) for customers.

Numeral Health API

The Health API from Numeral — 1 operation(s) for health.

Numeral Products API

The Products API from Numeral — 2 operation(s) for products.

Numeral Refunds API

The Refunds API from Numeral — 3 operation(s) for refunds.

Numeral Tax Calculations API

The Tax Calculations API from Numeral — 2 operation(s) for tax calculations.

Numeral Transactions API

The Transactions API from Numeral — 2 operation(s) for transactions.

Scroll for all 9

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Numeral API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Numeral Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Numeral Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Numeral Finops

FINOPS

Security Posture 2

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

Numeral Authentication

http · 1 scheme

SECURITY

Numeral Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Numeral Agentic Access

16 operations · 10 acting

16 operations · 10 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 2

The organization behind the API

LinkedIn
LinkedIn
 Website
Website

Source (apis.yml)

apis.yml Raw ↑ 
aid: numeral
url: https://raw.githubusercontent.com/api-evangelist/numeral/refs/heads/main/apis.yml
name: Numeral
kind: company
description: Numeral (Numeral HQ) is a sales-tax compliance and automation platform for ecommerce and SaaS companies. Its
  REST API calculates real-time sales tax by customer location at state, county, city, and district granularity, records transactions
  and refunds, and manages products and customers, while the broader platform handles registrations, nexus monitoring, filing,
  and remittance. Not to be confused with Numeral (numeral.io), an unrelated payment-operations company now part of Mambu.
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/numeral.png
tags:
- Sales Tax
- Tax Compliance
- Tax Calculation
- Ecommerce
- SaaS
created: '2026-06-21'
modified: '2026-06-21'
specificationVersion: '0.19'
apis:
- aid: numeral:filings
  name: Numeral Filings API
  tags:
  - Filings
  - Remittance
  - Autofile
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.numeral.com/product/api
  baseURL: https://api.numeralhq.com
  properties:
  - url: https://docs.numeral.com/api-reference/introduction
    type: Documentation
  - url: https://www.numeral.com/pricing
    type: Plans
  description: Sales-tax return filing and remittance (Autofile) across all US states, driven by recorded transactions. Filing
    and remittance are delivered as managed platform services rather than self-serve public REST endpoints; transaction data
    captured via the API flows into them.
- aid: numeral:registrations-nexus
  name: Numeral Registrations & Nexus API
  tags:
  - Registrations
  - Nexus
  - Monitoring
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.numeral.com/product/api
  baseURL: https://api.numeralhq.com
  properties:
  - url: https://docs.numeral.com/api-reference/introduction
    type: Documentation
  - url: https://www.numeral.com/pricing
    type: Plans
  description: State sales-tax registration (Autoregister) and physical/economic nexus monitoring with state-crossing alerts.
    Provided as managed platform services on top of API-captured transaction data rather than as self-serve public REST endpoints.
- aid: numeral:webhooks
  name: Numeral Webhooks
  tags:
  - Webhooks
  - Events
  - Notifications
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  properties:
  - url: https://docs.numeral.com/api-reference/introduction
    type: Documentation
  description: Event notifications for compliance and transaction lifecycle changes (e.g., filing, registration, and nexus
    events). Webhook delivery is offered through the Numeral platform; no public webhook subscription endpoint is documented
    in the REST API reference as of this writing (see review.yml).
- aid: numeral:numeral-customers-api
  name: Numeral Customers API
  description: The Customers API from Numeral — 2 operation(s) for customers.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Customers
  properties:
  - type: OpenAPI
    url: openapi/numeral-customers-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
- aid: numeral:numeral-health-api
  name: Numeral Health API
  description: The Health API from Numeral — 1 operation(s) for health.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Health
  properties:
  - type: OpenAPI
    url: openapi/numeral-health-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
- aid: numeral:numeral-products-api
  name: Numeral Products API
  description: The Products API from Numeral — 2 operation(s) for products.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Products
  properties:
  - type: OpenAPI
    url: openapi/numeral-products-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
- aid: numeral:numeral-refunds-api
  name: Numeral Refunds API
  description: The Refunds API from Numeral — 3 operation(s) for refunds.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Refunds
  properties:
  - type: OpenAPI
    url: openapi/numeral-refunds-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
- aid: numeral:numeral-tax-calculations-api
  name: Numeral Tax Calculations API
  description: The Tax Calculations API from Numeral — 2 operation(s) for tax calculations.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Tax Calculations
  properties:
  - type: OpenAPI
    url: openapi/numeral-tax-calculations-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
- aid: numeral:numeral-transactions-api
  name: Numeral Transactions API
  description: The Transactions API from Numeral — 2 operation(s) for transactions.
  humanURL: https://docs.numeral.com/api-reference/introduction
  baseURL: https://api.numeralhq.com
  tags:
  - Transactions
  properties:
  - type: OpenAPI
    url: openapi/numeral-transactions-api-openapi.yml
  - type: Documentation
    url: https://docs.numeral.com/api-reference/introduction
  - type: APIReference
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/calculations
  - type: PostmanCollection
    url: collections/numeral.postman_collection.json
  - type: OpenCollection
    url: collections/numeral.opencollection.json
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/transactions
  - type: Documentation
    url: https://docs.numeral.com/api-reference/v2026-03-01/endpoint/products
common:
- type: AgenticAccess
  url: agentic-access/numeral-agentic-access.yml
- type: DomainSecurity
  url: security/numeral-domain-security.yml
- type: Authentication
  url: authentication/numeral-authentication.yml
- type: GitHubOrganization
  url: https://github.com/numeralhq
- type: LinkedIn
  url: https://www.linkedin.com/company/numeralhq
- type: Website
  url: https://www.numeral.com/
- type: Documentation
  url: https://docs.numeral.com/api-reference/introduction
- type: Plans
  url: plans/numeral-plans-pricing.yml
- type: RateLimits
  url: rate-limits/numeral-rate-limits.yml
- type: FinOps
  url: finops/numeral-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com