Highline

Highline is an embedded payment infrastructure company whose Pay by Paycheck product captures funds from a consumer's payroll before they reach the checking account and routes them to billers and lenders. The platform pairs with payroll providers to create a split direct deposit at payroll run time, so designated bills are paid on time and in full, and the remainder is deposited to the consumer's bank as normal. Highline ships an API-first developer experience with hosted documentation at docs.highline.co, a Highline Link client widget, webhook-based notifications, sandbox simulations, daily ACH settlements, and an llms.txt for AI agents. The company is sometimes referenced as highline.fi but operates today at highline.co.

Highline publishes 10 API contracts indexed on the APIs.io network, including Auth API, Companies API, Connections API, and 7 more. Tagged areas include Embedded Finance, Payroll, Payments, ACH, and Bill Pay.

The Highline catalog on APIs.io includes 1 Spectral governance ruleset.

Highline’s developer surface includes authentication, documentation, engineering blog, and 14 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

23.9/100 emerging ▬ flat Agent 24/100 agent aware Front door AI 1/6 silent Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreeSelf serve⚡ Free to try

1 published contract

Embedded Finance Payroll Payments ACH Bill Pay Lending Direct Deposit API-First WebhookPay by Paycheck

Kin Score

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

Composite quality — 23.9/100 · emerging

Contract Quality 8.5 / 19

Developer Ergonomics 3.6 / 15

Access Clarity 0.8 / 15

Operational Transparency 0.5 / 10

Contract Governance 1.2 / 9

Discoverability 4.8 / 8

Regulatory Posture 1.6 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 24/100 · 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 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 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Payments 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
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
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)

7 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 5.3 — up to +18.9 composite points
Developer Ergonomics scores 23.8 — up to +15.2 composite points
Contract Quality scores 45.4 — up to +13.7 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/highline-fi/apis.yml: open an issue on github.com/api-evangelist/highline-fi 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 →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Consumer Lending Licensing (UK, US, Canada credit licence registers)	undeclared	-	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

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.

NACHA

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

OpenAPI

measured — observed by APIs.io (published)

APIs 10

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

Highline Pay by Paycheck API

The Highline API lets billers, lenders, and platforms verify consumer eligibility for paycheck-deduction payments, present the Highline Link flow to authorize a connection, subm...

Highline Auth API

The Auth API from Highline — 2 operation(s) for auth.

Highline Companies API

The Companies API from Highline — 1 operation(s) for companies.

Highline Connections API

The Connections API from Highline — 2 operation(s) for connections.

Highline Employments API

The Employments API from Highline — 1 operation(s) for employments.

Highline Payment Requests API

The Payment Requests API from Highline — 4 operation(s) for payment requests.

Highline Payments API

The Payments API from Highline — 3 operation(s) for payments.

Highline Products API

The Products API from Highline — 4 operation(s) for products.

Highline Settlements API

The Settlements API from Highline — 3 operation(s) for settlements.

Highline Users API

The Users API from Highline — 4 operation(s) for users.

Scroll for all 10

Open Collections 10

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

Highline Auth API

OPEN COLLECTION

Highline Auth Companies API

OPEN COLLECTION

Highline Auth Connections API

OPEN COLLECTION

Highline Auth Employments API

OPEN COLLECTION

Highline Auth Payment Requests API

OPEN COLLECTION

Highline Auth Payments API

OPEN COLLECTION

Highline Auth Products API

OPEN COLLECTION

Highline Auth Settlements API

OPEN COLLECTION

Highline Auth Users API

OPEN COLLECTION

Highline API

OPEN COLLECTION

Scroll for all 10

Highline API pricing

Not yet checked against Highline's own pricing page. Compiled by API Evangelist on 2026-05-22; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Pro Tier Default: 120 requests per minute

Compiled by API Evangelist, not yet checked against Highline's documentation. Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Highline Fi Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Highline Fi Rate Limits

2 limits

RATE LIMITS

Service Levels 1

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

Highline

SLA

FinOps 1

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

Highline Fi Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Highline API Rules

56 rules · 54 errors 1 warnings 1 info

SPECTRAL

Security Posture 2

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

Highline Fi Authentication

http · 1 scheme

SECURITY

Highline Fi Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Highline Fi Agentic Access

27 operations · 11 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 2

Status, limits, changes, and where to get help

RateLimits

RateLimits

Contact

Contact

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 6

The organization behind the API

Website

Website

About

About

Careers

Careers

LinkedIn

Crunchbase

Crunchbase

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Payroll

Payroll

PayrollAndHR

PayrollAndHR

Source (apis.yml)

aid: highline-fi
name: Highline
description: 'Highline is an embedded payment infrastructure company whose Pay by Paycheck

  product captures funds from a consumer''s payroll before they reach the

  checking account and routes them to billers and lenders. The platform pairs

  with payroll providers to create a split direct deposit at payroll run time,

  so designated bills are paid on time and in full, and the remainder is

  deposited to the consumer''s bank as normal. Highline ships an API-first

  developer experience with hosted documentation at docs.highline.co, a Highline

  Link client widget, webhook-based notifications, sandbox simulations, daily

  ACH settlements, and an llms.txt for AI agents. The company is sometimes

  referenced as highline.fi but operates today at highline.co.

  '
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Free · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
position: Producing
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/highline-fi.png
x-docs-platform: readme
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-03
tags:
- Embedded Finance
- Payroll
- Payments
- ACH
- Bill Pay
- Lending
- Direct Deposit
- API-First
- Webhook
- Pay by Paycheck
tags_raw:
- Embedded Finance
- Payroll
- Payments
- ACH
- Bill Pay
- Lending
- Direct Deposit
- API-First
- Webhooks
- Pay by Paycheck
url: https://raw.githubusercontent.com/api-evangelist/highline-fi/refs/heads/main/apis.yml
created: '2026-05-23'
modified: '2026-05-23'
specificationVersion: '0.23'
apis:
- aid: highline-fi:pay-by-paycheck-api
  name: Highline Pay by Paycheck API
  description: 'The Highline API lets billers, lenders, and platforms verify consumer

    eligibility for paycheck-deduction payments, present the Highline Link

    flow to authorize a connection, submit and manage payment requests, and

    reconcile daily ACH settlements. It is documented at docs.highline.co

    with API keys, webhooks, simulations, and an llms.txt index for AI

    agents.

    '
  humanURL: https://docs.highline.co/
  tags:
  - Payments
  - Eligibility
  - Link
  - Webhook
  - Settlement
  - Reconciliation
  tags_raw:
  - Payments
  - Eligibility
  - Link
  - Webhooks
  - Settlements
  - Reconciliation
  properties:
  - type: Documentation
    url: https://docs.highline.co/
  - type: Website
    url: https://highline.co/
  - type: Payroll
    url: https://highline.co/payroll/
  - type: PayrollAndHR
    url: https://highline.co/for-payroll-and-hr-providers/
  - type: LlmsText
    url: https://docs.highline.co/llms.txt
  - type: LinkedIn
    url: https://www.linkedin.com/company/highlineco/
  features:
  - name: Eligibility API
    description: Check whether a consumer qualifies for Pay by Paycheck based on payroll connections.
  - name: Highline Link
    description: Client-side widget for users to authorize a connection between their employer payroll and the biller or lender.
  - name: Payment Requests
    description: Submit, update, and cancel payment requests for upcoming paychecks.
  - name: Payment Monitoring
    description: Track status of in-flight payments in real time.
  - name: Daily ACH Settlements
    description: Receive funds via same-day or daily ACH batch transfers.
  - name: Reconciliation Reports
    description: Pull settlement reports for arbitrary date ranges.
  - name: Webhooks
    description: Subscribe to payment lifecycle events with signed webhook verification.
  - name: Sandbox Simulations
    description: Test integration flows end-to-end against a sandbox environment.
  - name: llms.txt for AI Agents
    description: Markdown-formatted page index and OpenAPI endpoints exposed at docs.highline.co/llms.txt.
  useCases:
  - name: Lender Loan Repayment
    description: Lenders ensure on-time, in-full loan repayments by collecting from paychecks before consumer checking accounts
      receive funds.
  - name: Biller Recurring Payments
    description: Billers reduce churn by routing recurring bills through paycheck deductions.
  - name: Payroll Platform Partnership
    description: Payroll providers offer Highline as a partner capability to their employer customers.
  - name: Embedded Consumer Apps
    description: Consumer fintech apps embed Pay by Paycheck for automated bill management.
  - name: Hardship Programs
    description: Lenders and billers offer paycheck-aligned hardship programs to consumers.
  integrations:
  - name: ACH network
  - name: Payroll providers
  - name: Direct deposit systems
  - name: Banking platforms
  - name: Lending platforms
  - name: Billing platforms
  authentication:
  - type: APIKey
    description: API keys issued through the Highline dashboard, with sandbox and live environments.
  - type: Webhooks
    description: Signed webhooks for payment lifecycle events with verification mechanisms.
- aid: highline-fi:highline-fi-auth-api
  name: Highline Auth API
  description: The Auth API from Highline — 2 operation(s) for auth.
  humanURL: https://docs.highline.co/
  tags:
  - Authentication
  tags_raw:
  - Auth
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-auth-api-openapi.yml
- aid: highline-fi:highline-fi-companies-api
  name: Highline Companies API
  description: The Companies API from Highline — 1 operation(s) for companies.
  humanURL: https://docs.highline.co/
  tags:
  - Companies
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-companies-api-openapi.yml
- aid: highline-fi:highline-fi-connections-api
  name: Highline Connections API
  description: The Connections API from Highline — 2 operation(s) for connections.
  humanURL: https://docs.highline.co/
  tags:
  - Connections
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-connections-api-openapi.yml
- aid: highline-fi:highline-fi-employments-api
  name: Highline Employments API
  description: The Employments API from Highline — 1 operation(s) for employments.
  humanURL: https://docs.highline.co/
  tags:
  - Employments
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-employments-api-openapi.yml
- aid: highline-fi:highline-fi-payment-requests-api
  name: Highline Payment Requests API
  description: The Payment Requests API from Highline — 4 operation(s) for payment requests.
  humanURL: https://docs.highline.co/
  tags:
  - Payment Requests
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-payment-requests-api-openapi.yml
- aid: highline-fi:highline-fi-payments-api
  name: Highline Payments API
  description: The Payments API from Highline — 3 operation(s) for payments.
  humanURL: https://docs.highline.co/
  tags:
  - Payments
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-payments-api-openapi.yml
- aid: highline-fi:highline-fi-products-api
  name: Highline Products API
  description: The Products API from Highline — 4 operation(s) for products.
  humanURL: https://docs.highline.co/
  tags:
  - Product
  tags_raw:
  - Products
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-products-api-openapi.yml
- aid: highline-fi:highline-fi-settlements-api
  name: Highline Settlements API
  description: The Settlements API from Highline — 3 operation(s) for settlements.
  humanURL: https://docs.highline.co/
  tags:
  - Settlement
  tags_raw:
  - Settlements
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-settlements-api-openapi.yml
- aid: highline-fi:highline-fi-users-api
  name: Highline Users API
  description: The Users API from Highline — 4 operation(s) for users.
  humanURL: https://docs.highline.co/
  tags:
  - User
  tags_raw:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/highline-fi-users-api-openapi.yml
common:
- type: Plans
  url: plans/highline-fi-plans-pricing.yml
- type: RateLimits
  url: rate-limits/highline-fi-rate-limits.yml
- type: FinOps
  url: finops/highline-fi-finops.yml
- type: AgenticAccess
  url: agentic-access/highline-fi-agentic-access.yml
- type: DomainSecurity
  url: security/highline-fi-domain-security.yml
- type: Authentication
  url: authentication/highline-fi-authentication.yml
- type: Website
  url: https://highline.co/
- type: Payroll
  url: https://highline.co/payroll/
- type: PayrollAndHR
  url: https://highline.co/for-payroll-and-hr-providers/
- type: Documentation
  url: https://docs.highline.co/
- type: LlmsText
  url: https://docs.highline.co/llms.txt
- type: About
  url: https://highline.co/about/
- type: Careers
  url: https://highline.co/careers/
- type: Contact
  url: https://highline.co/contact/
- type: LinkedIn
  url: https://www.linkedin.com/company/highlineco/
- type: Crunchbase
  url: https://www.crunchbase.com/organization/HighlineCo
- url: https://highline.co/feed/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Highline API — frequently asked questions

Does Highline have an API?

Yes. APIs.io lists 10 APIs from Highline, including Highline Pay by Paycheck API, Highline Auth API and Highline Companies API, and 7 more.

Is there an OpenAPI specification for the Highline API?

Yes. APIs.io indexes 9 OpenAPI specifications for Highline, each linked for download from this page.

How do I authenticate with the Highline API?

Highline uses bearer-token authentication (http · 1 scheme). The details are profiled on APIs.io as Highline Fi Authentication.

How much does the Highline API cost?

APIs.io lists 1 pricing plan for Highline, with each plan's price, limits and inclusions under Pricing on this page.

Is the Highline API ready for AI agents?

Highline has a Kin Score of 23.9 out of 100 (emerging) and an Agent Readiness score of 23.8 (agent-aware), scored by API Evangelist on 2026-11-06.

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