HackMD

HackMD is a real-time collaborative Markdown editor and knowledge base for individuals and teams. Multiple people can co-edit a Markdown document live, organize notes into folders and team workspaces, and publish them as web pages, slide decks or books. HackMD exposes a v1 REST API at api.hackmd.io that lets developers programmatically create, read, update and delete personal and team notes, manage folders and folder ordering, upload image attachments, restore notes from trash, and read the current user profile and view history. The API authenticates with a personal access token sent as an HTTP bearer credential, is described by a published OpenAPI 3.0 specification and Swagger UI, ships an official Node.js/TypeScript client (@hackmd/api) and command-line interface, and advertises its full developer surface through an RFC 9727 api-catalog. HackMD is a Techstars-backed company.

HackMD publishes 8 APIs on the APIs.io network, including History API, Profile API, Team Folders API, and 5 more. Tagged areas include Company, Markdown, Collaboration, Documentation, and Note Taking.

HackMD’s developer surface includes documentation, API reference, getting-started guide, engineering blog, pricing, signup flow, changelog, and 24 more developer resources.

🌐 Visit website 📡 Source on GitHub
50.4/100 developing ▬ flat Agent 62/100 agent native Full breakdown ↓
scored 2026-07-23 · rubric v0.5
AccessSelf serve
8 APIs 1 MCP Servers
CompanyMarkdownCollaborationDocumentationNote TakingKnowledge BaseProductivityContent

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-23 · rubric v0.5
Composite quality — 50.4/100 · developing
Contract Quality 11.5 / 25
Developer Ergonomics 15.2 / 20
Commercial Clarity 8.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 62/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/hackmd: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 8

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

HackMD History API

Operations related to user's note history.

HackMD Profile API

Operations to retrieve user profile information.

HackMD Team Folders API

Operations related to folders within a team.

HackMD Team Notes API

Operations related to notes within a team.

HackMD Teams API

Operations related to user teams.

HackMD Trash API

Operations for listing and restoring trashed notes.

HackMD User Folders API

Operations related to a user's personal folders.

HackMD User Notes API

Operations related to a user's personal notes.

Scroll for all 8

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

hackmd-mcp.yml

MCP SERVER

Rate Limits 1

Documented rate limits and quota policies.

Hackmd Rate Limits

0 limits

RATE LIMITS

Security Posture 2

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

Hackmd Authentication

http · 1 scheme

SECURITY

Hackmd Domain Security

TLSv1.2 · HSTS · DNSSEC · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 SignUp
SignUp

Documentation 3

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference
 OpenAPI
OpenAPI

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer
MCPServer
 AgentSkill
AgentSkill
 LLMsTxt
LLMsTxt
 WellKnown
WellKnown

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 DataModel
DataModel
 Conformance
Conformance

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages
 SDKs
SDKs
 CLI
CLI

Access & Security 2

Authentication, authorization, and security posture

Authentication
Authentication
 DomainSecurity
DomainSecurity

Operate 3

Status, limits, changes, and where to get help

StatusPage
StatusPage
 ChangeLog
ChangeLog
 RateLimits
RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Other 2

Properties that don't map to a standard resource type

Overlay
Overlay
 APICatalog
APICatalog

Source (apis.yml)

apis.yml Raw ↑ 
aid: hackmd
name: HackMD
description: HackMD is a real-time collaborative Markdown editor and knowledge base for individuals and teams. Multiple people
  can co-edit a Markdown document live, organize notes into folders and team workspaces, and publish them as web pages, slide
  decks or books. HackMD exposes a v1 REST API at api.hackmd.io that lets developers programmatically create, read, update
  and delete personal and team notes, manage folders and folder ordering, upload image attachments, restore notes from trash,
  and read the current user profile and view history. The API authenticates with a personal access token sent as an HTTP bearer
  credential, is described by a published OpenAPI 3.0 specification and Swagger UI, ships an official Node.js/TypeScript client
  (@hackmd/api) and command-line interface, and advertises its full developer surface through an RFC 9727 api-catalog. HackMD
  is a Techstars-backed company.
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://hackmd.io/favicon.png
url: https://raw.githubusercontent.com/api-evangelist/hackmd/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- techstars
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Markdown
- Collaboration
- Documentation
- Note Taking
- Knowledge Base
- Productivity
- Content
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: hackmd:hackmd-history-api
  name: HackMD History API
  description: Operations related to user's note history.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - History
  properties:
  - type: OpenAPI
    url: openapi/hackmd-history-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-profile-api
  name: HackMD Profile API
  description: Operations to retrieve user profile information.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - Profile
  properties:
  - type: OpenAPI
    url: openapi/hackmd-profile-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-team-folders-api
  name: HackMD Team Folders API
  description: Operations related to folders within a team.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - Team Folders
  properties:
  - type: OpenAPI
    url: openapi/hackmd-team-folders-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-team-notes-api
  name: HackMD Team Notes API
  description: Operations related to notes within a team.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - Team Notes
  properties:
  - type: OpenAPI
    url: openapi/hackmd-team-notes-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-teams-api
  name: HackMD Teams API
  description: Operations related to user teams.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - Teams
  properties:
  - type: OpenAPI
    url: openapi/hackmd-teams-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-trash-api
  name: HackMD Trash API
  description: Operations for listing and restoring trashed notes.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - Trash
  properties:
  - type: OpenAPI
    url: openapi/hackmd-trash-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-user-folders-api
  name: HackMD User Folders API
  description: Operations related to a user's personal folders.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - User Folders
  properties:
  - type: OpenAPI
    url: openapi/hackmd-user-folders-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
- aid: hackmd:hackmd-user-notes-api
  name: HackMD User Notes API
  description: Operations related to a user's personal notes.
  humanURL: https://hackmd.io/@docs/developer-portal
  baseURL: https://api.hackmd.io/v1
  tags:
  - User Notes
  properties:
  - type: OpenAPI
    url: openapi/hackmd-user-notes-api-openapi.yml
  - type: APIReference
    url: https://api.hackmd.io/v1/docs/
  - type: Documentation
    url: https://hackmd.io/@docs/developer-portal
  - type: Authentication
    url: authentication/hackmd-authentication.yml
  - type: RateLimits
    url: rate-limits/hackmd-rate-limits.yml
common:
- type: Website
  url: https://hackmd.io/
- type: DeveloperPortal
  url: https://hackmd.io/@docs/developer-portal
- type: Documentation
  url: https://hackmd.io/@docs/developer-portal
- type: APIReference
  url: https://api.hackmd.io/v1/docs/
- type: GettingStarted
  url: https://hackmd.io/@docs/how-to-issue-an-api-token
- type: GitHubOrganization
  url: https://github.com/hackmdio
- type: Blog
  url: https://hackmd.io/blog
- type: Pricing
  url: https://hackmd.io/pricing
- type: SignUp
  url: https://hackmd.io/login
- type: TermsOfService
  url: https://hackmd.io/s/terms
- type: PrivacyPolicy
  url: https://hackmd.io/s/privacy
- type: StatusPage
  url: https://status.hackmd.io/
- type: ChangeLog
  url: changelog/hackmd-changelog.yml
- type: Authentication
  url: authentication/hackmd-authentication.yml
- type: OpenAPI
  url: openapi/hackmd-openapi-original.json
- type: Overlay
  url: overlays/hackmd-openapi-overlay.yaml
- type: Packages
  url: packages/hackmd-packages.yml
- type: SDKs
  url: packages/hackmd-packages.yml
- type: CLI
  url: cli/hackmd-cli.yml
- type: MCPServer
  url: mcp/hackmd-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/hackmd-llms.txt
- type: WellKnown
  url: well-known/hackmd-well-known.yml
- type: APICatalog
  url: well-known/hackmd-api-catalog.json
- type: Conventions
  url: conventions/hackmd-conventions.yml
- type: ErrorCatalog
  url: errors/hackmd-problem-types.yml
- type: RateLimits
  url: rate-limits/hackmd-rate-limits.yml
- type: Lifecycle
  url: lifecycle/hackmd-lifecycle.yml
- type: DataModel
  url: data-model/hackmd-data-model.yml
- type: Conformance
  url: conformance/hackmd-conformance.yml
- type: DomainSecurity
  url: security/hackmd-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence