Mattermark

Mattermark is a business-intelligence platform for data-driven deal making, providing profiles on roughly four million companies and twenty million key contacts along with their investors, funding events, and news. Relaunched as an independent company, Mattermark exposes its dataset through a REST API (api.mattermark.com) and a GraphQL API (eapi.mattermark.com), both authenticated with a Bearer API key and queryable with the Mattermark Search Filter Language (MSFL). Originally an a16z / Slow Ventures / Version One Ventures-backed startup, it is tracked in the API Evangelist network as a company profile.

Mattermark publishes 6 APIs on the APIs.io network, including Companies API, Complex Queries API, Funding Events API, and 3 more. Tagged areas include Company, Business Intelligence, Company Data, Investors, and Funding.

Mattermark’s developer surface includes documentation, API reference, getting-started guide, pricing, engineering blog, authentication, changelog, and 23 more developer resources.

🌐 Visit website 📡 Source on GitHub

47.0/100 developing ▬ flat Agent 29/100 agent ready Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessPaid

2 APIs

Company Business Intelligence Company Data Investors Funding Sales Intelligence Market Research

Kin Score

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

Composite quality — 47.0/100 · developing

Contract Quality 12.8 / 23

Developer Ergonomics 9.3 / 18

Access Clarity 11.4 / 18

Operational Transparency 2.2 / 12

Contract Governance 0.5 / 11

Discoverability 6.8 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 29/100 · agent ready

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 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

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/mattermark: 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 7

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

Mattermark GraphQL API

GraphQL access to the Mattermark dataset using the Mattermark Search Filter Language (MSFL) for complex company and investor queries. Read-only: the published schema declares 57...

Mattermark Companies API

The Companies API from Mattermark — 5 operation(s) for companies.

Mattermark Complex Queries API

The Complex Queries API from Mattermark — 1 operation(s) for complex queries.

Mattermark Funding Events API

The Funding Events API from Mattermark — 1 operation(s) for funding events.

Mattermark Investors API

The Investors API from Mattermark — 2 operation(s) for investors.

Mattermark Search API

The Search API from Mattermark — 1 operation(s) for search.

Mattermark Utilities API

The Utilities API from Mattermark — 1 operation(s) for utilities.

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Mattermark Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Mattermark Rate Limits

0 limits

RATE LIMITS

Security Posture 2

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

Mattermark Authentication

apiKey/http · 2 schemes

SECURITY

Mattermark Domain Security

TLSv1.3

SECURITY

Agentic Access 1

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

Mattermark Agentic Access

11 operations · 1 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Sandbox

Sandbox

Documentation 4

Reference material describing how the API behaves

Documentation

APIReference

OpenAPI

GraphQL

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

X-MCPServerCandidate

X-MCPServerCandidate

AgentSkill

AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

ToolCrosswalk

ToolCrosswalk

Packages

Packages

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

RateLimits

RateLimits

ChangeLog

ChangeLog

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 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: mattermark
deliveryModel:
  model: unknown
  open_source: unknown
  commercial: true
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  - pricing
  - repository-unlicensed
  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: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/mattermark.png
name: Mattermark
description: Mattermark is a business-intelligence platform for data-driven deal making, providing profiles on roughly four
  million companies and twenty million key contacts along with their investors, funding events, and news. Relaunched as an
  independent company, Mattermark exposes its dataset through a REST API (api.mattermark.com) and a GraphQL API (eapi.mattermark.com),
  both authenticated with a Bearer API key and queryable with the Mattermark Search Filter Language (MSFL). Originally an
  a16z / Slow Ventures / Version One Ventures-backed startup, it is tracked in the API Evangelist network as a company profile.
url: https://raw.githubusercontent.com/api-evangelist/mattermark/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- a16z
- slow-ventures
- version-one-ventures
x-tier: profiled
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-08-14'
tags:
- Company
- Business Intelligence
- Company Data
- Investors
- Funding
- Sales Intelligence
- Market Research
apis:
- name: Mattermark GraphQL API
  description: 'GraphQL access to the Mattermark dataset using the Mattermark Search Filter Language (MSFL) for complex company
    and investor queries. Read-only: the published schema declares 57 types under a single RootQuery and no mutation type.
    Organizations model both companies and investors, discriminated by companyPersona / investorPersona.'
  humanURL: https://developer.mattermark.com/graphql
  baseURL: https://eapi.mattermark.com/
  properties:
  - type: GraphQL
    url: graphql/mattermark.graphql
  - type: Documentation
    url: https://developer.mattermark.com/graphql
  - type: Documentation
    name: Mattermark GraphQL API docs (docs.mattermark.com)
    url: https://docs.mattermark.com/graphql_api/index.html
  - type: Authentication
    url: authentication/mattermark-authentication.yml
- aid: mattermark:mattermark-companies-api
  name: Mattermark Companies API
  description: The Companies API from Mattermark — 5 operation(s) for companies.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Companies
  properties:
  - type: OpenAPI
    url: openapi/mattermark-companies-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
- aid: mattermark:mattermark-complex-queries-api
  name: Mattermark Complex Queries API
  description: The Complex Queries API from Mattermark — 1 operation(s) for complex queries.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Complex Queries
  properties:
  - type: OpenAPI
    url: openapi/mattermark-complex-queries-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
- aid: mattermark:mattermark-funding-events-api
  name: Mattermark Funding Events API
  description: The Funding Events API from Mattermark — 1 operation(s) for funding events.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Funding Events
  properties:
  - type: OpenAPI
    url: openapi/mattermark-funding-events-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
- aid: mattermark:mattermark-investors-api
  name: Mattermark Investors API
  description: The Investors API from Mattermark — 2 operation(s) for investors.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Investors
  properties:
  - type: OpenAPI
    url: openapi/mattermark-investors-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
- aid: mattermark:mattermark-search-api
  name: Mattermark Search API
  description: The Search API from Mattermark — 1 operation(s) for search.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/mattermark-search-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
- aid: mattermark:mattermark-utilities-api
  name: Mattermark Utilities API
  description: The Utilities API from Mattermark — 1 operation(s) for utilities.
  humanURL: https://developer.mattermark.com/reference
  baseURL: https://api.mattermark.com/
  tags:
  - Utilities
  properties:
  - type: OpenAPI
    url: openapi/mattermark-utilities-api-openapi.yml
  - type: Documentation
    url: https://developer.mattermark.com/docs
  - type: Documentation
    url: https://docs.mattermark.com/rest_api/index.html
  - type: APIReference
    url: https://developer.mattermark.com/reference
  - type: SourceCode
    url: https://github.com/Mattermark/mattermark-openapi
  - type: Authentication
    url: authentication/mattermark-authentication.yml
  - type: Conventions
    url: conventions/mattermark-conventions.yml
  - type: ErrorCatalog
    url: errors/mattermark-problem-types.yml
  - type: DataModel
    url: data-model/mattermark-data-model.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/mattermark-agentic-access.yml
- type: Website
  url: https://mattermark.com
- type: DeveloperPortal
  url: https://developer.mattermark.com/
- type: Documentation
  url: https://developer.mattermark.com/docs
- type: APIReference
  url: https://developer.mattermark.com/reference
- type: GettingStarted
  url: https://developer.mattermark.com/docs
- type: Pricing
  url: https://mattermark.com/pricing
- type: TermsOfService
  url: https://mattermark.com/terms
- type: PrivacyPolicy
  url: https://mattermark.com/privacy-policy/
- type: Blog
  url: https://mattermark.com/blog
- type: GitHubOrganization
  url: https://github.com/mattermark
- type: LLMsTxt
  url: llms/mattermark-llms.txt
- type: Authentication
  url: authentication/mattermark-authentication.yml
- type: Conventions
  url: conventions/mattermark-conventions.yml
- type: ErrorCatalog
  url: errors/mattermark-problem-types.yml
- type: RateLimits
  url: rate-limits/mattermark-rate-limits.yml
- type: Lifecycle
  url: lifecycle/mattermark-lifecycle.yml
- type: ChangeLog
  url: changelog/mattermark-changelog.yml
- type: X-MCPServerCandidate
  url: mcp/mattermark-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: ToolCrosswalk
  url: mcp/mattermark-tool-crosswalk.yml
- type: Packages
  url: packages/mattermark-packages.yml
- type: Conformance
  url: conformance/mattermark-conformance.yml
- type: DataModel
  url: data-model/mattermark-data-model.yml
- type: DomainSecurity
  url: security/mattermark-domain-security.yml
- type: OpenAPI
  url: openapi/mattermark-rest-api-openapi.yml
- type: GraphQL
  url: graphql/mattermark.graphql
- type: Overlay
  url: overlays/mattermark-rest-api-overlay.yaml
- type: Sandbox
  url: sandbox/mattermark-sandbox.yml
- type: Plans
  url: plans/mattermark-plans-pricing.yml
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-08-14'
  status: enriched
  artifacts_added: 13
  pass: local-v1

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