Exclaimer

Exclaimer is an email signature management platform used by IT, marketing, and sales teams to centrally create, deploy, and govern corporate email signatures across Microsoft 365, Microsoft Exchange, and Google Workspace. It manages signatures for more than 9 million email accounts, adding campaign banners, meeting-branding backgrounds, click-tracking analytics, directory synchronization with Azure AD and Google Directory, and role-based access control. Exclaimer publishes the Exclaimer Cloud API — a partner/distributor provisioning REST API documented at cloudapi.exclaimer.com with a machine- readable OpenAPI 3.0.1 definition covering subscriptions, MSP subscriptions, subscription users, resellers, end users, mailbox counts, subscription transfers and reference data. It operates a multi-region Exclaimer Cloud with a real-time status page and a strong security and compliance program (SOC 2 Type II, ISO 27001/27018, HIPAA, PCI DSS, CSA STAR, Cyber Essentials).

Exclaimer publishes 9 API contracts indexed on the APIs.io network, including End Users API, Mailboxes API, Miscellaneous API, and 6 more. Tagged areas include Company, Email, Email Signatures, Email Signature Management, and Microsoft 365.

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

Exclaimer’s developer surface includes pricing, engineering blog, signup flow, documentation, API reference, getting-started guide, support, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

67.7/100 exemplar ▬ flat Agent 30/100 agent ready Front door AI 1/6 silent Heartbeat 58/100 slowing saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

10 published contracts 4 Agent Skills

Company EmailEmail SignaturesEmail Signature Management Microsoft 365 Google Workspace Marketing Productivity Software-as-a-Service Security

What this lets a business do 2

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Subscription Lifecycle Management

BC-4240

MSPMailboxesSubscription TransfersSubscriptions

POST /1.0/msp/subscriptions GET /1.0/msp/subscriptions GET /1.0/msp/subscriptions/{SubscriptionID} GET /1.0/msp/subscriptions/{SubscriptionID}/status

Sales Management

BC-410

Resellers

PUT /1.0/resellers GET /1.0/resellers

Kin Score

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

Composite quality — 67.7/100 · exemplar

Contract Quality 10.6 / 19

Developer Ergonomics 9.9 / 15

Access Clarity 15.0 / 15

Operational Transparency 5.1 / 10

Contract Governance 1.6 / 9

Discoverability 5.9 / 8

Regulatory Posture 5.3 / 15

Create-or-Update Ergonomics 1.1 / 10

Agent readiness — 30/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 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 Horizontal (data, software, accessibility, platform) 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
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
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)

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 56.7 — up to +10.8 composite points
Contract Governance scores 18.2 — up to +9.8 composite points
Developer Ergonomics scores 66.1 — up to +6.8 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/exclaimer/apis.yml: open an issue on github.com/api-evangelist/exclaimer 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
Workplace Collaboration App Marketplaces	builds-on	47.1	-	-
Zoom App Marketplace and Partner Ecosystem (builders and partners on Zoom)	builds-on	47.1	-	-
HubSpot App Marketplace (CRM add-ons, outbound, performance marketing, chat)	builds-on	47.1	-	-

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 1

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.

OpenAPI

measured — observed by APIs.io (published)

APIs 9

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

Exclaimer End Users API

The End Users API from Exclaimer — 1 operation(s) for end users.

Exclaimer Mailboxes API

The Mailboxes API from Exclaimer — 1 operation(s) for mailboxes.

Exclaimer Miscellaneous API

The Miscellaneous API from Exclaimer — 2 operation(s) for miscellaneous.

Exclaimer MSP API

The MSP API from Exclaimer — 4 operation(s) for msp.

Exclaimer Reference Resources API

The Reference Resources API from Exclaimer — 3 operation(s) for reference resources.

Exclaimer Resellers API

The Resellers API from Exclaimer — 1 operation(s) for resellers.

Exclaimer Subscription Transfers API

The Subscription Transfers API from Exclaimer — 3 operation(s) for subscription transfers.

Exclaimer Subscription Users API

The Subscription Users API from Exclaimer — 4 operation(s) for subscription users.

Exclaimer Subscriptions API

The Subscriptions API from Exclaimer — 13 operation(s) for subscriptions.

Scroll for all 9

Open Collections 9

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

Exclaimer Cloud API — End Users

OPEN COLLECTION

Exclaimer Cloud API — Mailboxes

OPEN COLLECTION

Exclaimer Cloud API — Miscellaneous

OPEN COLLECTION

Exclaimer Cloud API — MSP

OPEN COLLECTION

Exclaimer Cloud API — Reference Resources

OPEN COLLECTION

Exclaimer Cloud API — Resellers

OPEN COLLECTION

Exclaimer Cloud API — Subscription Transfers

OPEN COLLECTION

Exclaimer Cloud API — Subscription Users

OPEN COLLECTION

Exclaimer Cloud API — Subscriptions

OPEN COLLECTION

Scroll for all 9

Agent Skills 4

Packaged agent skills for driving this provider's APIs from an AI assistant.

exclaimer-manage-seats-and-users

AGENT SKILL

exclaimer-msp-usage-reporting

AGENT SKILL

exclaimer-provision-subscription

AGENT SKILL

exclaimer-transfer-subscription

AGENT SKILL

Exclaimer API pricing

Prices published by Exclaimer, read 2026-10-28 from exclaimer.com/pricing/.

Plan	Price
Starter	$0.90 Includes: Centrally managed email signatures, 1 signature template, 1 Brand Kit, single promotional banner
Standard	$1.45 Includes: Unlimited email signature templates, three Brand Kits, campaign scheduling
Pro	$1.75 Includes: Unlimited brands, engagement dashboard, HRIS directory integration
Enterprise	Custom pricing based on your requirements Includes: Standard or Pro plans plus dedicated CSM and guided implementation

Plan details, limits and sources →

Billed by: user / month, billed annually · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Exclaimer Plans Pricing

4 plans

PLANS

Exclaimer Price Estimates

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Exclaimer Rate Limits

0 limits

RATE LIMITS

Service Levels 1

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

Exclaimer

SLA

FinOps 1

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

Exclaimer Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Exclaimer API Rules

55 rules · 52 errors 2 warnings 1 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Exclaimer Cloud Api Overlay

44 actions · servers · exclaimer-cloud-api-openapi.json

DERIVED

Security Posture 4

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

Exclaimer Authentication

apiKey · 1 scheme

SECURITY

Exclaimer Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Exclaimer Vulnerability Disclosure

security.txt · contact published

SECURITY

Exclaimer Trust Center

SOC 2 Type II, ISO/IEC 27001, ISO/IEC 27018, PCI DSS, CSA (Cloud Security Alliance), Cyber Essentials, HIPAA, GDPR, CCPA

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

SignUp

SignUp

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

AgentSkill

WellKnown

WellKnown

LLMsTxt

LLMsTxt

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Lifecycle

Lifecycle

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 6

Authentication, authorization, and security posture

Compliance

Compliance

TrustCenter

TrustCenter

Security

Security

VulnerabilityDisclosure

VulnerabilityDisclosure

SecurityTxt

SecurityTxt

DomainSecurity

DomainSecurity

Operate 6

Status, limits, changes, and where to get help

RateLimits

HelpCenter

StatusPage

Support

ChangeLog

Deprecation

Commercial 4

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

Plans

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Overlay

Overlay

Source (apis.yml)

aid: exclaimer
name: Exclaimer
description: Exclaimer is an email signature management platform used by IT, marketing, and sales teams to centrally create,
  deploy, and govern corporate email signatures across Microsoft 365, Microsoft Exchange, and Google Workspace. It manages
  signatures for more than 9 million email accounts, adding campaign banners, meeting-branding backgrounds, click-tracking
  analytics, directory synchronization with Azure AD and Google Directory, and role-based access control. Exclaimer publishes
  the Exclaimer Cloud API — a partner/distributor provisioning REST API documented at cloudapi.exclaimer.com with a machine-
  readable OpenAPI 3.0.1 definition covering subscriptions, MSP subscriptions, subscription users, resellers, end users, mailbox
  counts, subscription transfers and reference data. It operates a multi-region Exclaimer Cloud with a real-time status page
  and a strong security and compliance program (SOC 2 Type II, ISO 27001/27018, HIPAA, PCI DSS, CSA STAR, Cyber Essentials).
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: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-11-06'
  method: derived
image: https://exclaimer.com/img/og-image.jpg
url: https://raw.githubusercontent.com/api-evangelist/exclaimer/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- insight-partners
x-tier: enriched
x-tier-reason: 'Promoted from stub 2026-08-13: the Exclaimer Cloud API and its OpenAPI 3.0.1 were discovered and captured,
  with 22 artifacts wired.'
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-08-13'
tags:
- Company
- Email
- Email Signatures
- Email Signature Management
- Microsoft 365
- Google Workspace
- Marketing
- Productivity
- Software-as-a-Service
- Security
tags_raw:
- Company
- Email
- Email Signatures
- Email Signature Management
- Microsoft 365
- Google Workspace
- Marketing
- Productivity
- SaaS
- Security
- Microsoft-365
apis:
- aid: exclaimer:exclaimer-end-users-api
  name: Exclaimer End Users API
  description: The End Users API from Exclaimer — 1 operation(s) for end users.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - End Users
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-end-users-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-mailboxes-api
  name: Exclaimer Mailboxes API
  description: The Mailboxes API from Exclaimer — 1 operation(s) for mailboxes.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Mailboxes
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-mailboxes-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-miscellaneous-api
  name: Exclaimer Miscellaneous API
  description: The Miscellaneous API from Exclaimer — 2 operation(s) for miscellaneous.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags: []
  tags_raw:
  - Miscellaneous
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-miscellaneous-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-msp-api
  name: Exclaimer MSP API
  description: The MSP API from Exclaimer — 4 operation(s) for msp.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - MSP
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-msp-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-reference-resources-api
  name: Exclaimer Reference Resources API
  description: The Reference Resources API from Exclaimer — 3 operation(s) for reference resources.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Reference Resources
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-reference-resources-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-resellers-api
  name: Exclaimer Resellers API
  description: The Resellers API from Exclaimer — 1 operation(s) for resellers.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Resellers
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-resellers-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-subscription-transfers-api
  name: Exclaimer Subscription Transfers API
  description: The Subscription Transfers API from Exclaimer — 3 operation(s) for subscription transfers.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Subscription Transfers
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-subscription-transfers-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-subscription-users-api
  name: Exclaimer Subscription Users API
  description: The Subscription Users API from Exclaimer — 4 operation(s) for subscription users.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Subscription Users
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-subscription-users-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
- aid: exclaimer:exclaimer-subscriptions-api
  name: Exclaimer Subscriptions API
  description: The Subscriptions API from Exclaimer — 13 operation(s) for subscriptions.
  humanURL: https://cloudapi.exclaimer.com/
  baseURL: https://cloudapi.exclaimer.com/exclaimerapi
  tags:
  - Subscription
  tags_raw:
  - Subscriptions
  properties:
  - type: OpenAPI
    url: openapi/exclaimer-subscriptions-api-openapi.yml
  - type: APIReference
    url: https://cloudapi.exclaimer.com/
  - type: Documentation
    url: https://cloudapi.exclaimer.com/
  - type: Authentication
    url: authentication/exclaimer-authentication.yml
  - type: Conventions
    url: conventions/exclaimer-conventions.yml
  - type: ErrorCatalog
    url: errors/exclaimer-problem-types.yml
  - type: DataModel
    url: data-model/exclaimer-data-model.yml
  - type: RateLimits
    url: rate-limits/exclaimer-rate-limits.yml
  - type: Sandbox
    url: sandbox/exclaimer-sandbox.yml
  - type: Conformance
    url: conformance/exclaimer-conformance.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: RateLimits
  url: rate-limits/exclaimer-rate-limits.yml
- type: CapabilityMap
  url: capabilities/exclaimer-capability-edges.yml
  name: Exclaimer Business Capability Map
- type: Overlay
  url: overlays/exclaimer-cloud-api-overlay.yaml
- type: AgentSkill
  url: skills/_index.yml
- type: Website
  url: https://exclaimer.com/
- type: Pricing
  url: https://exclaimer.com/pricing/
- type: Blog
  url: https://exclaimer.com/blog/
- type: SignUp
  url: https://go.exclaimer.com/trial
- type: HelpCenter
  url: https://support.exclaimer.com/hc/en-gb
- type: TermsOfService
  url: https://exclaimer.com/legal/website-terms-of-use/
- type: PrivacyPolicy
  url: https://exclaimer.com/legal/privacy-policy/
- type: StatusPage
  url: https://status.exclaimer.com/
- type: Lifecycle
  url: lifecycle/exclaimer-lifecycle.yml
- type: Compliance
  url: https://exclaimer.com/product/security/
- type: TrustCenter
  url: security/exclaimer-trust-center.yml
- type: Security
  url: https://vdp.exclaimer.com/p/Welcome
- type: VulnerabilityDisclosure
  url: security/exclaimer-vulnerability-disclosure.yml
- type: SecurityTxt
  url: well-known/exclaimer-security.txt
- type: WellKnown
  url: well-known/exclaimer-well-known.yml
- type: DomainSecurity
  url: security/exclaimer-domain-security.yml
- type: DeveloperPortal
  url: https://cloudapi.exclaimer.com/
- type: Documentation
  url: https://support.exclaimer.com/hc/en-gb
- type: APIReference
  url: https://cloudapi.exclaimer.com/
- type: GettingStarted
  url: https://support.exclaimer.com/hc/en-gb/articles/360050643511-Onboarding-Connect-to-Microsoft-365
- type: Support
  url: https://support.exclaimer.com/hc/en-gb
- type: GitHubOrganization
  url: https://github.com/exclaimerltd
- type: ChangeLog
  url: changelog/exclaimer-changelog.yml
- type: Deprecation
  url: https://exclaimer.com/support/discontinued/
- type: LLMsTxt
  url: llms/exclaimer-llms.txt
- type: Plans
  url: plans/exclaimer-plans-pricing.yml
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 22
  pass: local-v1
  note: Round 1 (2026-07-19) recorded "Exclaimer does not publish a public developer API reference". That was wrong. STEP
    0b contract discovery found the Exclaimer Cloud API reference at https://cloudapi.exclaimer.com/ — server-rendered, not
    a JS shell — with a real OpenAPI 3.0.1 served anonymously at https://cloudapi.exclaimer.com/openapi.json (HTTP 200, 39
    operations, 59 schemas). The docs are public; only the ExApiToken is gated to the distributor network.

Exclaimer API — frequently asked questions

Does Exclaimer have an API?

Yes. APIs.io lists 9 APIs from Exclaimer, including Exclaimer End Users API, Exclaimer Mailboxes API and Exclaimer Miscellaneous API, and 6 more.

Is there an OpenAPI specification for the Exclaimer API?

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

How do I authenticate with the Exclaimer API?

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

How much does the Exclaimer API cost?

Exclaimer publishes its prices; its Starter plan is $0.90 as of 2026-10-28. APIs.io lists 4 pricing plans for Exclaimer, with each plan's price, limits and inclusions under Pricing on this page.

Is the Exclaimer API ready for AI agents?

Exclaimer has a Kin Score of 67.7 out of 100 (exemplar) and an Agent Readiness score of 30.0 (agent-ready), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/exclaimer"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/exclaimer/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/exclaimer/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

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