Digital Public Library of America

The Digital Public Library of America (DPLA) provides a free REST API that gives access to metadata for 50 million+ cultural heritage items aggregated from 4,000+ US libraries, archives, and museums. The API supports full-text search, field-specific queries, geographic and date range filtering, faceted browsing, and JSONP callbacks. All results are returned as JSON-LD. API keys are issued free of charge via a self-service email-based registration endpoint. DPLA aggregates contributions from cultural heritage institutions across the United States and makes the combined metadata freely available to researchers, developers, and the public.

Digital Public Library of America publishes 4 APIs on the APIs.io network, including Authentication API, Items API, Primary Source Sets API, and 1 more. Tagged areas include Cultural Heritage, Libraries, Archives, Museums, and Open Data.

The Digital Public Library of America catalog on APIs.io includes 1 JSON-LD context.

Digital Public Library of America’s developer surface includes authentication, documentation, engineering blog, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub
38.4/100 thin ▬ flat Agent 31/100 agent ready open core · MIT Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessFreeSelf serve⚡ Free to try
1 APIs
Cultural HeritageLibrariesArchivesMuseumsOpen DataMetadataDigital CollectionsPublic Domain

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Composite quality — 38.4/100 · thin
Contract Quality 11.7 / 19
Developer Ergonomics 6.8 / 15
Access Clarity 4.3 / 15
Operational Transparency 0.3 / 10
Contract Governance 0.0 / 9
Discoverability 5.1 / 8
Regulatory Posture 4.7 / 15
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 31/100 · 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 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
Regulatory Posture applies to this provider. Its tags matched the Government & Public Sector 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/.
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/dpla: 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 5

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

DPLA API Key Registration

Self-service API key registration endpoint that issues free access keys via email. Developers submit their email address via HTTP POST and receive an API key by email. The key i...

Digital Public Library of America Authentication API

API key registration and management

Digital Public Library of America Items API

Search and retrieve cultural heritage item metadata records

Digital Public Library of America Primary Source Sets API

Search and retrieve primary source sets (PSS) for education

Digital Public Library of America Utilities API

Utility endpoints for health checks and random item retrieval

Open Collections 5

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

API Collection

OPEN COLLECTION

Digital Public Library of America (DPLA) Authentication API

OPEN COLLECTION

Digital Public Library of America (DPLA) Authentication Items API

OPEN COLLECTION

Digital Public Library of America (DPLA) Authentication Primary Source Sets API

OPEN COLLECTION

Digital Public Library of America (DPLA) Authentication Utilities API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Plans

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Rate Limits

0 limits

RATE LIMITS

FinOps 1

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

Finops

FINOPS

Semantic Vocabularies 1

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

context Context

47 classes · 0 properties

JSON-LD

Security Posture 2

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

Dpla Authentication

apiKey · 2 schemes

SECURITY

Dpla Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

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

Dpla Agentic Access

8 operations · 1 acting

8 operations · 1 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLDContext
JSONLDContext

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 GitHubRepository
GitHubRepository

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 3

Pricing, plans, and the legal terms of use

License
License
 Plans
Plans
 FinOps
FinOps

Company 4

The organization behind the API

Website
Website
 Blog
Blog
 LinkedIn
LinkedIn
 Twitter
Twitter

Source (apis.yml)

apis.yml Raw ↑ 
aid: dpla
name: Digital Public Library of America
description: The Digital Public Library of America (DPLA) provides a free REST API that gives access to metadata for 50 million+
  cultural heritage items aggregated from 4,000+ US libraries, archives, and museums. The API supports full-text search, field-specific
  queries, geographic and date range filtering, faceted browsing, and JSONP callbacks. All results are returned as JSON-LD.
  API keys are issued free of charge via a self-service email-based registration endpoint. DPLA aggregates contributions from
  cultural heritage institutions across the United States and makes the combined metadata freely available to researchers,
  developers, and the public.
type: Index
deliveryModel:
  model: open-core
  license: MIT
  open_source: true
  commercial: true
  callable_host: true
  label: Open core · an OSS project plus a commercial hosted product
  confidence: high
  source:
  - license
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
position: Producing
access: Public
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/dpla.png
tags:
- Cultural Heritage
- Libraries
- Archives
- Museums
- Open Data
- Metadata
- Digital Collections
- Public Domain
url: https://raw.githubusercontent.com/api-evangelist/dpla/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
apis:
- aid: dpla:api-key-registration
  name: DPLA API Key Registration
  description: Self-service API key registration endpoint that issues free access keys via email. Developers submit their
    email address via HTTP POST and receive an API key by email. The key is then passed as the api_key query parameter or
    Authorization header on all subsequent Items API requests.
  humanURL: https://pro.dp.la/developers/api-codex
  baseURL: https://api.dp.la/v2
  tags:
  - Authentication
  - APIKeys
  - Registration
  tags_raw:
  - Authentication
  - API Keys
  - Registration
  properties:
  - type: Documentation
    url: https://pro.dp.la/developers/api-codex
- aid: dpla:dpla-authentication-api
  name: Digital Public Library of America Authentication API
  description: API key registration and management
  humanURL: https://pro.dp.la/developers/api-codex
  baseURL: https://api.dp.la/v2
  tags:
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/dpla-authentication-api-openapi.yml
  - type: Documentation
    url: https://pro.dp.la/developers/api-codex
  - type: GettingStarted
    url: https://pro.dp.la/developers/api-codex
  - type: Authentication
    url: https://pro.dp.la/developers/api-codex
  - type: GitHubRepository
    url: https://github.com/dpla/api
- aid: dpla:dpla-items-api
  name: Digital Public Library of America Items API
  description: Search and retrieve cultural heritage item metadata records
  humanURL: https://pro.dp.la/developers/api-codex
  baseURL: https://api.dp.la/v2
  tags:
  - Item
  tags_raw:
  - Items
  properties:
  - type: OpenAPI
    url: openapi/dpla-items-api-openapi.yml
  - type: Documentation
    url: https://pro.dp.la/developers/api-codex
  - type: GettingStarted
    url: https://pro.dp.la/developers/api-codex
  - type: Authentication
    url: https://pro.dp.la/developers/api-codex
  - type: GitHubRepository
    url: https://github.com/dpla/api
- aid: dpla:dpla-primary-source-sets-api
  name: Digital Public Library of America Primary Source Sets API
  description: Search and retrieve primary source sets (PSS) for education
  humanURL: https://pro.dp.la/developers/api-codex
  baseURL: https://api.dp.la/v2
  tags:
  - Primary Source Sets
  properties:
  - type: OpenAPI
    url: openapi/dpla-primary-source-sets-api-openapi.yml
  - type: Documentation
    url: https://pro.dp.la/developers/api-codex
  - type: GettingStarted
    url: https://pro.dp.la/developers/api-codex
  - type: Authentication
    url: https://pro.dp.la/developers/api-codex
  - type: GitHubRepository
    url: https://github.com/dpla/api
- aid: dpla:dpla-utilities-api
  name: Digital Public Library of America Utilities API
  description: Utility endpoints for health checks and random item retrieval
  humanURL: https://pro.dp.la/developers/api-codex
  baseURL: https://api.dp.la/v2
  tags:
  - Utilities
  properties:
  - type: OpenAPI
    url: openapi/dpla-utilities-api-openapi.yml
  - type: Documentation
    url: https://pro.dp.la/developers/api-codex
  - type: GettingStarted
    url: https://pro.dp.la/developers/api-codex
  - type: Authentication
    url: https://pro.dp.la/developers/api-codex
  - type: GitHubRepository
    url: https://github.com/dpla/api
common:
- type: License
  name: MIT
  url: https://github.com/dpla/api/blob/main/LICENSE
- type: AgenticAccess
  url: agentic-access/dpla-agentic-access.yml
- type: DomainSecurity
  url: security/dpla-domain-security.yml
- type: Authentication
  url: authentication/dpla-authentication.yml
- type: Website
  url: https://dp.la/
- type: DeveloperPortal
  url: https://pro.dp.la/developers
- type: Documentation
  url: https://pro.dp.la/developers/api-codex
- type: GitHubOrganization
  url: https://github.com/dpla
- type: GitHubRepository
  url: https://github.com/dpla/api
- type: Blog
  url: https://dp.la/news
- type: LinkedIn
  url: https://www.linkedin.com/company/digital-public-library-of-america
- type: Twitter
  url: https://twitter.com/dpla
- type: RateLimits
  url: https://raw.githubusercontent.com/api-evangelist/dpla/refs/heads/main/rate-limits/rate-limits.yml
- type: Plans
  url: https://raw.githubusercontent.com/api-evangelist/dpla/refs/heads/main/plans/plans.yml
- type: FinOps
  url: https://raw.githubusercontent.com/api-evangelist/dpla/refs/heads/main/finops/finops.yml
- type: JSONLDContext
  url: https://raw.githubusercontent.com/api-evangelist/dpla/refs/heads/main/json-ld/context.jsonld
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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