Capacities

Capacities is a note‑taking and knowledge‑management app that organizes ideas as connected objects instead of traditional files and folders. It offers a free tier across macOS, Windows, Linux, iOS, and Android, focusing on linking thoughts, visualizing relationships, and enhancing personal knowledge workflows.

Capacities publishes 4 API contracts indexed on the APIs.io network, including Blocks API, Object API, Objects API, and 1 more. Tagged areas include Knowledge Management, Note Taking, Productivity, Cross-Platform, and Collaboration.

The Capacities catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Capacities’ developer surface includes authentication, support, changelog, API reference, documentation, engineering blog, pricing, and 23 more developer resources.

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50.7/100 developing Agent 47/100 agent ready Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaidSelf serve

1 published contract

Knowledge Management Note Taking Productivity Cross-Platform Collaboration

Kin Score

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

Composite quality — 50.7/100 · developing

Contract Quality 13.1 / 21

Developer Ergonomics 6.1 / 17

Access Clarity 8.1 / 17

Operational Transparency 5.8 / 11

Contract Governance 3.6 / 10

Discoverability 5.7 / 9

Regulatory Posture 3.1 / 15

Agent readiness — 47/100 · 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 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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<a href="https://apis.io/providers/capacities-io/"><img src="https://apis.io/badge/capacities-io/card.svg" alt="Capacities on APIs.io — Kin Score by API Evangelist"></a>

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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
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

4 more unmet checks in the Agent Readiness table above.

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

Developer Ergonomics scores 35.7 — up to +12.9 composite points
Access Clarity scores 47.4 — up to +10.5 composite points
Contract Quality scores 61.8 — up to +9.6 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/capacities-io/apis.yml: open an issue on github.com/api-evangelist/capacities-io 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 →

Standards implemented 3

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.

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 4

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

Capacities Blocks API

Block content operations on objects

Capacities Object API

Operations on objects in a space

Capacities Objects API

Search and list objects in a space

Capacities Space API

Space related operations

Capacities API pricing

Prices published by Capacities. A free plan or tier is listed.

Plan	Price
Capacities Basic	Free Includes: Unlimited spaces, objects, and blocks
Capacities Pro	$9.99/month USD Includes: Everything in Free, and AI assistant, Whiteboards, Task management, Smart queries, Calendar integrat
Capacities Believer	from $12.49/month USD Includes: Everything in Pro, and Boost a product you love, Beta access to major new features

Plan details, limits and sources →

Rate limits

General request rate limit: RateLimit: limit=5, remaining=4, reset=58
General request rate limit (exhaustion response): RateLimit: limit=5, remaining=0, reset=43
Object creation quota: Hard limit 10,000 objects

Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Capacities Io Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Capacities Io Rate Limits

3 limits

RATE LIMITS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Capacities Io Context

63 classes · 41 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Capacities API Rules

53 rules · 45 errors 4 warnings 4 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

ApiBlock

0 properties

JSON SCHEMA

ApiIconOutput

2 properties

JSON SCHEMA

ApiLabelOptionOutput

3 properties

JSON SCHEMA

AppendBlocksPosition

0 properties

JSON SCHEMA

CreateObjectFromUrlProperties

2 properties

JSON SCHEMA

WritableApiBlock

0 properties

JSON SCHEMA

Security Posture 2

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

Capacities Io Authentication

2 schemes

SECURITY

Capacities Io Domain Security

TLSv1.3 · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Capacities Io Agentic Access

22 operations · 14 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

Documentation 2

Reference material describing how the API behaves

APIReference

APIReference

Documentation

Documentation

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conformance

Build 3

SDKs, sample code, and the tooling you integrate with

SDKs

SDKs

Packages

Packages

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 5

Status, limits, changes, and where to get help

RateLimits

Support

StatusPage

Roadmap

ChangeLog

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 3

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Leadership

Leadership

Source (apis.yml)

aid: capacities-io
name: Capacities
accessModel:
  pricing: paid
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Paid · Self-serve signup
  confidence: high
  probe_state: gated
  source:
  - plans
  - authentication
  - rate-limits
  - security
  generated: '2026-11-06'
  method: derived
image: https://capacities.io/thumbnail/thumbnail_index.png
description: Capacities is a note‑taking and knowledge‑management app that organizes ideas as connected objects instead of
  traditional files and folders. It offers a free tier across macOS, Windows, Linux, iOS, and Android, focusing on linking
  thoughts, visualizing relationships, and enhancing personal knowledge workflows.
url: https://artifacts.apis.io/capacities-io/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-04 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-04'
modified: '2026-11-04'
tags:
- Knowledge Management
- Note Taking
- Productivity
- Cross-Platform
- Collaboration
tags_raw:
- Knowledge Management
- Note Taking
- Productivity
- Cross‑Platform
- Collaboration
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/capacities-io-agentic-access.yml
- type: RateLimits
  url: rate-limits/capacities-io-rate-limits.yml
- type: Plans
  url: plans/capacities-io-plans-pricing.yml
- type: Spectral
  url: rules/capacities-io-rules.yml
- type: JSONLD
  url: json-ld/capacities-io-context.jsonld
- type: Vocabulary
  url: vocabulary/capacities-io-vocabulary.yml
- type: DataModel
  url: data-model/capacities-io-data-model.yml
- type: Authentication
  url: authentication/capacities-io-authentication.yml
- type: Conformance
  url: conformance/capacities-io-conformance.yml
- type: LLMsTxt
  url: llms/capacities-io-llms.txt
- type: WellKnown
  url: well-known/capacities-io-well-known.yml
- type: Hosts
  url: hosts/capacities-io-hosts.yml
- type: Vendors
  url: vendors/capacities-io-vendors.yml
- type: SDKs
  url: packages/capacities-io-packages.yml
- type: Packages
  url: packages/capacities-io-packages.yml
- type: TermsOfService
  url: https://capacities.io/terms-and-conditions
- type: Support
  url: https://capacities.io/help
- type: StatusPage
  url: https://status.capacities.io
- type: Roadmap
  url: https://capacities.io/roadmap
- type: PrivacyPolicy
  url: https://capacities.io/privacy-policy
- type: Leadership
  url: https://capacities.io/about/team
- type: ChangeLog
  url: https://capacities.io/whats-new
- type: APIReference
  url: https://docs.capacities.io/raw/developer/api.md
- type: GitHubOrganization
  url: https://github.com/capacities
- type: DomainSecurity
  url: security/capacities-io-domain-security.yml
- type: Website
  url: https://capacities.io/
- type: Documentation
  url: https://docs.capacities.io
- type: DeveloperPortal
  url: https://docs.capacities.io
- type: Blog
  url: https://capacities.io/blog
- type: Pricing
  url: https://capacities.io/pricing
apis:
- aid: capacities-io:capacities-io-blocks-api
  name: Capacities Blocks API
  description: Block content operations on objects
  humanURL: https://developers.capacities.io
  baseURL: https://api.capacities.io
  tags:
  - Blocks
  properties:
  - type: OpenAPI
    url: openapi/capacities-io-blocks-api-openapi.yml
  - type: JSONSchema
    url: json-schema/capacities-io-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-writable-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-icon-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-append-blocks-position-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-label-option-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-create-object-from-url-properties-schema.json
- aid: capacities-io:capacities-io-object-api
  name: Capacities Object API
  description: Operations on objects in a space
  humanURL: https://developers.capacities.io
  baseURL: https://api.capacities.io
  tags:
  - Object
  properties:
  - type: OpenAPI
    url: openapi/capacities-io-object-api-openapi.yml
  - type: JSONSchema
    url: json-schema/capacities-io-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-writable-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-icon-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-append-blocks-position-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-label-option-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-create-object-from-url-properties-schema.json
- aid: capacities-io:capacities-io-objects-api
  name: Capacities Objects API
  description: Search and list objects in a space
  humanURL: https://developers.capacities.io
  baseURL: https://api.capacities.io
  tags:
  - Objects
  properties:
  - type: OpenAPI
    url: openapi/capacities-io-objects-api-openapi.yml
  - type: JSONSchema
    url: json-schema/capacities-io-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-writable-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-icon-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-append-blocks-position-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-label-option-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-create-object-from-url-properties-schema.json
- aid: capacities-io:capacities-io-space-api
  name: Capacities Space API
  description: Space related operations
  humanURL: https://developers.capacities.io
  baseURL: https://api.capacities.io
  tags:
  - Space
  properties:
  - type: OpenAPI
    url: openapi/capacities-io-space-api-openapi.yml
  - type: JSONSchema
    url: json-schema/capacities-io-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-writable-api-block-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-icon-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-append-blocks-position-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-api-label-option-output-schema.json
  - type: JSONSchema
    url: json-schema/capacities-io-create-object-from-url-properties-schema.json
x-coverage:
  state: gated
  reason: partner-login
  method: derived
  generated: '2026-11-04'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company serves an API surface but requires credentials before any description of it can be read
  evidence:
  - url: https://developers.capacities.io/openapi.json
    status: null
  - url: https://feedback.capacities.io/api/mcp
    status: 401
  - url: https://capacities.io/
    status: 200
x-enrichment:
  date: '2026-11-04'
  status: enriched
  artifacts_added: 27
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Capacities API — frequently asked questions

Does Capacities have an API?

Yes. APIs.io lists 4 APIs from Capacities, including Capacities Blocks API, Capacities Object API and Capacities Objects API, and 1 more.

Is there an OpenAPI specification for the Capacities API?

Yes. APIs.io indexes 4 OpenAPI specifications for Capacities, each linked for download from this page.

How do I authenticate with the Capacities API?

Capacities documents its authentication (2 schemes). The details are profiled on APIs.io as Capacities Io Authentication.

How much does the Capacities API cost?

Capacities publishes its prices; its Capacities Pro plan is $9.99/month USD as of 2026-11-04. APIs.io lists 3 pricing plans for Capacities, with each plan's price, limits and inclusions under Pricing on this page.

Is the Capacities API ready for AI agents?

Capacities has a Kin Score of 50.7 out of 100 (developing) and an Agent Readiness score of 46.9 (agent-ready), scored by API Evangelist on 2026-11-06.

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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.
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