Sequence

Sequence is a usage-based billing, pricing, and revenue orchestration platform for B2B SaaS and other recurring-revenue businesses. It turns product usage and negotiated contract terms into automated billing schedules, invoices, credit notes, and quotes, backed by a metering engine for usage events and usage metrics, plus revenue recognition and integrations to ERP/CRM, tax, and payment providers. The REST API (production base https://eu.sequencehq.com) uses HTTP Basic authentication with a Client ID and Client Secret, date-based API versioning (for example sequence-version 2024-07-30), and signed webhooks for event notifications. A Sandbox environment (https://sandbox.sequencehq.com) mirrors production for testing.

Sequence publishes 6 APIs on the APIs.io network, including Billing Schedules API, Customers API, Invoices API, and 3 more. Tagged areas include Billing, Usage-Based Billing, Revenue Recognition, Metering, and Invoicing.

Sequence’s developer surface includes authentication, documentation, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub

23.5/100 emerging ▬ flat Agent 20/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessPaid

1 APIs

Billing Usage-Based Billing Revenue Recognition Metering Invoicing Pricing Revenue Orchestration FinOps

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 23.5/100 · emerging

Contract Quality 0.0 / 23

Developer Ergonomics 5.8 / 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 — 20/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 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 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/sequence-hq: 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 6

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

Sequence Billing Schedules API

Recurring contract terms that generate invoices.

Sequence Customers API

Billable customer entities, contacts, and aliases.

Sequence Invoices API

Invoice and credit note lifecycle.

Sequence Products API

Product and price catalog.

Sequence Quotes API

Quotes and quote analytics.

Sequence Usage API

Usage event ingestion, usage metrics, and seats.

Open Collections 8

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

API Collection

OPEN COLLECTION

Sequence Billing Schedules API

OPEN COLLECTION

Sequence Billing Schedules Customers API

OPEN COLLECTION

Sequence Billing Schedules Invoices API

OPEN COLLECTION

Sequence Billing Schedules Products API

OPEN COLLECTION

Sequence Billing Schedules Quotes API

OPEN COLLECTION

Sequence Billing Schedules Usage API

OPEN COLLECTION

Sequence API

OPEN COLLECTION

Scroll for all 8

Pricing Plans 1

Published pricing tiers and plan structures.

Sequence Hq Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Sequence Hq Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Sequence Hq Finops

FINOPS

Security Posture 2

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

Sequence Hq Authentication

http · 1 scheme

SECURITY

Sequence Hq Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Sequence Hq Agentic Access

20 operations · 9 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 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: sequence-hq
url: https://raw.githubusercontent.com/api-evangelist/sequence-hq/refs/heads/main/apis.yml
name: Sequence
kind: company
description: Sequence is a usage-based billing, pricing, and revenue orchestration platform for B2B SaaS and other recurring-revenue
  businesses. It turns product usage and negotiated contract terms into automated billing schedules, invoices, credit notes,
  and quotes, backed by a metering engine for usage events and usage metrics, plus revenue recognition and integrations to
  ERP/CRM, tax, and payment providers. The REST API (production base https://eu.sequencehq.com) uses HTTP Basic authentication
  with a Client ID and Client Secret, date-based API versioning (for example sequence-version 2024-07-30), and signed webhooks
  for event notifications. A Sandbox environment (https://sandbox.sequencehq.com) mirrors production for testing.
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: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/sequence-hq.png
tags:
- Billing
- Usage-Based Billing
- Revenue Recognition
- Metering
- Invoicing
- Pricing
- Revenue Orchestration
- FinOps
created: '2026-07-12'
modified: '2026-07-12'
specificationVersion: '0.23'
apis:
- aid: sequence-hq:sequence-hq-billing-schedules-api
  name: Sequence Billing Schedules API
  description: Recurring contract terms that generate invoices.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Billing Schedules
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-billing-schedules-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
- aid: sequence-hq:sequence-hq-customers-api
  name: Sequence Customers API
  description: Billable customer entities, contacts, and aliases.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Customers
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-customers-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
- aid: sequence-hq:sequence-hq-invoices-api
  name: Sequence Invoices API
  description: Invoice and credit note lifecycle.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Invoices
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-invoices-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
- aid: sequence-hq:sequence-hq-products-api
  name: Sequence Products API
  description: Product and price catalog.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Product
  tags_raw:
  - Products
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-products-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
- aid: sequence-hq:sequence-hq-quotes-api
  name: Sequence Quotes API
  description: Quotes and quote analytics.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Quotes
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-quotes-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
- aid: sequence-hq:sequence-hq-usage-api
  name: Sequence Usage API
  description: Usage event ingestion, usage metrics, and seats.
  humanURL: https://docs.sequencehq.com/reference/latest/customer/list-customers
  baseURL: https://eu.sequencehq.com
  tags:
  - Usage
  properties:
  - type: OpenAPI
    url: openapi/sequence-hq-usage-api-openapi.yml
  - type: Documentation
    url: https://docs.sequencehq.com/reference/gettingStarted
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/customer/list-customers
  - type: PostmanCollection
    url: collections/sequence-hq.postman_collection.json
  - type: OpenCollection
    url: collections/sequence-hq.opencollection.json
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/usage/create-a-new-usage-event
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/billing/list-all-billing-schedules
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/invoices/list-all-invoices
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/product/list-all-products
  - type: APIReference
    url: https://docs.sequencehq.com/reference/latest/quote/list-quotes
common:
- type: AgenticAccess
  url: agentic-access/sequence-hq-agentic-access.yml
- type: DomainSecurity
  url: security/sequence-hq-domain-security.yml
- type: Authentication
  url: authentication/sequence-hq-authentication.yml
- type: GitHubOrganization
  url: https://github.com/sequencehq
- type: LinkedIn
  url: https://www.linkedin.com/company/sequence-hq
- type: Website
  url: https://www.sequencehq.com
- type: Documentation
  url: https://docs.sequencehq.com
- type: Plans
  url: plans/sequence-hq-plans-pricing.yml
- type: RateLimits
  url: rate-limits/sequence-hq-rate-limits.yml
- type: FinOps
  url: finops/sequence-hq-finops.yml
- url: https://www.sequencehq.com/blog
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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