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, E-Commerce, and Software-as-a-Service.

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

🌐 Visit website 📡 Source on GitHub

35.3/100 thin ▬ flat Agent 22/100 agent aware saas Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0

AccessFreemiumSelf serve⚡ Free to try

1 APIs

Sales Tax Tax Compliance Tax Calculation E-Commerce Software-as-a-Service

Kin Score

Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0

Composite quality — 35.3/100 · thin

Contract Quality 11.0 / 23

Developer Ergonomics 5.4 / 18

Access Clarity 7.1 / 18

Operational Transparency 2.8 / 12

Contract Governance 0.0 / 11

Discoverability 6.2 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

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.

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 github.com/api-evangelist/numeral: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

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 8

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

API Collection

OPEN COLLECTION

Numeral Customers API

OPEN COLLECTION

Numeral Customers Health API

OPEN COLLECTION

Numeral Customers Products API

OPEN COLLECTION

Numeral Customers Refunds API

OPEN COLLECTION

Numeral Customers Tax Calculations API

OPEN COLLECTION

Numeral Customers Transactions API

OPEN COLLECTION

Numeral API

OPEN COLLECTION

Scroll for all 8

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

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

Website

Website

Source (apis.yml)

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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/numeral.png
tags:
- Sales Tax
- Tax Compliance
- Tax Calculation
- E-Commerce
- Software-as-a-Service
tags_raw:
- Sales Tax
- Tax Compliance
- Tax Calculation
- Ecommerce
- SaaS
created: '2026-06-21'
modified: '2026-06-21'
specificationVersion: '0.23'
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:
  - Webhook
  - Event
  - Notification
  tags_raw:
  - 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:
  - Product
  tags_raw:
  - 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:
  - Transaction
  tags_raw:
  - 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

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