Symmetry

Symmetry provides payroll tax compliance software that enables employers, payroll providers, and platforms to calculate and file employee and employer taxes. Its products include a tax engine, payroll forms automation, I‑9 verification, payroll point location‑based tax rates, and minimum‑wage data for the United States and Canada. The company targets payroll providers, vertical payroll platforms, EOR and PEO services, recruiting and staffing firms, and large employers seeking automated, compliant payroll tax solutions.

Symmetry is profiled on the APIs.io network. Tagged areas include Payroll Tax Compliance, Payroll Platforms, EOR, PEO, and Recruiting.

The Symmetry catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Symmetry’s developer surface includes authentication, pricing, getting-started guide, documentation, API reference, and 14 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

33.7/100 thin Agent 39/100 agent ready Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

0 APIs

Payroll Tax CompliancePayroll PlatformsEORPEO Recruiting StaffingLarge EmployersTax APIs

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 33.7/100 · thin

Contract Quality 8.3 / 21

Developer Ergonomics 6.9 / 17

Access Clarity 5.4 / 17

Operational Transparency 3.8 / 11

Contract Governance 0.0 / 10

Discoverability 4.3 / 9

Regulatory Posture 2.9 / 15

Agent readiness — 39/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 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 0 / 7

Typed Event Surface 6 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

Regulatory Posture applies to this provider. Its tags matched the Employment & Payroll 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% 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
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)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

6 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 39.0 — up to +15.3 composite points
Access Clarity scores 31.6 — up to +13.7 composite points
Contract Governance scores 0.0 — up to +12.0 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/symmetry/apis.yml: open an issue on github.com/api-evangelist/symmetry 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 →

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Symmetry Webhooks

ASYNCAPI

Security Posture 2

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

Symmetry Authentication

5 schemes

SECURITY

Symmetry Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Webhooks

Webhooks

Conventions

Conventions

Access & Security 4

Authentication, authorization, and security posture

Authentication

SecurityTxt

Security

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

StatusPage

StatusPage

Commercial 3

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Pricing

Pricing

Company 2

The organization behind the API

Newsroom

Newsroom

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: symmetry
name: Symmetry
image: https://www.symmetry.com/symmetry-link-preview.png
description: Symmetry provides payroll tax compliance software that enables employers, payroll providers, and platforms to
  calculate and file employee and employer taxes. Its products include a tax engine, payroll forms automation, I‑9 verification,
  payroll point location‑based tax rates, and minimum‑wage data for the United States and Canada. The company targets payroll
  providers, vertical payroll platforms, EOR and PEO services, recruiting and staffing firms, and large employers seeking
  automated, compliant payroll tax solutions.
url: https://raw.githubusercontent.com/api-evangelist/symmetry/refs/heads/main/apis.yml
x-type: company
x-source: harvest:g2-catalog
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-21 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-21'
modified: '2026-10-21'
tags:
- Payroll Tax Compliance
- Payroll Platforms
- EOR
- PEO
- Recruiting
- Staffing
- Large Employers
- Tax APIs
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Webhooks
  url: asyncapi/symmetry-webhooks.yml
- type: Conventions
  url: conventions/symmetry-conventions.yml
- type: Authentication
  url: authentication/symmetry-authentication.yml
- type: LLMsTxt
  url: llms/symmetry-llms.txt
- type: SecurityTxt
  url: well-known/symmetry-status-security.txt
- type: WellKnown
  url: well-known/symmetry-well-known.yml
- type: Hosts
  url: hosts/symmetry-hosts.yml
- type: Vendors
  url: vendors/symmetry-vendors.yml
- type: TermsOfService
  url: https://www.symmetry.com/terms
- type: StatusPage
  url: https://status.symmetry.com
- type: Security
  url: https://www.symmetry.com/security
- type: PrivacyPolicy
  url: https://www.symmetry.com/privacy
- type: Pricing
  url: https://www.symmetry.com/pricing
- type: Newsroom
  url: https://www.symmetry.com/press
- type: GettingStarted
  url: https://docs.symmetry.com/ste/quickstarts/hosted-api-quickstart
- type: Documentation
  url: https://docs.symmetry.com/
- type: APIReference
  url: https://api.symmetry.com/i9/docs
- type: DomainSecurity
  url: security/symmetry-domain-security.yml
- type: Website
  url: https://symmetry.com/
apis: []
x-coverage:
  state: none
  reason: no-developer-program
  method: derived
  generated: '2026-10-21'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company publishes no developer documentation host and no machine-readable contract on its own domain
  evidence:
  - url: https://docs.symmetry.com/mcp
    status: null
  - url: https://api.symmetry.com/mcp
    status: 403
  - url: https://symmetry.com/mcp
    status: 403
  - url: https://symmetry.com/
    status: 200
x-enrichment:
  date: '2026-10-21'
  status: enriched
  artifacts_added: 14
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Symmetry API — frequently asked questions

How do I authenticate with the Symmetry API?

Symmetry documents its authentication (5 schemes). The details are profiled on APIs.io as Symmetry Authentication.

Is the Symmetry API ready for AI agents?

Symmetry has a Kin Score of 33.7 out of 100 (thin) and an Agent Readiness score of 38.8 (agent-ready), scored by API Evangelist on 2026-10-31.

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