Project Nessie

Project Nessie is an open-source project providing a transactional catalog for data lakes, offering Git‑like semantics for versioned data. It enables users to manage and query data across multiple storage systems, supports branching, tagging, and merging of data states, and integrates with tools such as Apache Iceberg, Spark, Flink, and Hive. The project aims to simplify data governance, reproducibility, and collaboration in modern data engineering workflows, fostering a community-driven ecosystem with extensive documentation, guides, and community support.

Project Nessie publishes 1 API contract indexed on the APIs.io network: Config API. Tagged areas include Company, Open Source, Data Lake, Version Control, and Community.

The Project Nessie catalog on APIs.io includes 1 Spectral governance ruleset.

Project Nessie’s developer surface includes changelog, documentation, API reference, getting-started guide, engineering blog, and 13 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

22.4/100 emerging ▼ -5.3 Agent 22/100 agent aware Heartbeat 49/100 alive Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract

Company Open Source Data Lake Version Control Community

Kin Score

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

Composite quality — 22.4/100 · emerging

Contract Quality 6.2 / 21

Developer Ergonomics 4.1 / 17

Access Clarity 0.0 / 17

Operational Transparency 2.0 / 11

Contract Governance 1.9 / 10

Discoverability 5.3 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 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 4 / 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 does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

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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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
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document

6 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 0.0 — up to +20.0 composite points
Contract Quality scores 29.4 — up to +17.7 composite points
Developer Ergonomics scores 24.3 — up to +15.1 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/project-nessie/apis.yml: open an issue on github.com/api-evangelist/project-nessie 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 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 1

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

Project Nessie Config API

The Config API from Project Nessie — 1 operation(s) for config.

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Project Nessie API Rules

7 rules · 5 errors 1 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.

Project Nessie Openapi Overlay

0 actions · update

UNRECORDED

Security Posture 1

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

Project Nessie Domain Security

TLSv1.3 · HSTS · DNSSEC

SECURITY

Agentic Access 1

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

Project Nessie Agentic Access

1 operation

1 operations · 0 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

AgentSkill

AgenticAccess

AgenticAccess

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Spectral

Spectral

ErrorCatalog

ErrorCatalog

Conformance

Conformance

Build 1

SDKs, sample code, and the tooling you integrate with

SourceCode

SourceCode

Access & Security 2

Authentication, authorization, and security posture

Security

Security

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

ChangeLog

ChangeLog

ChangeLog

ChangeLog

Community

Community

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: project-nessie
name: Project Nessie
description: Project Nessie is an open-source project providing a transactional catalog for data lakes, offering Git‑like
  semantics for versioned data. It enables users to manage and query data across multiple storage systems, supports branching,
  tagging, and merging of data states, and integrates with tools such as Apache Iceberg, Spark, Flink, and Hive. The project
  aims to simplify data governance, reproducibility, and collaboration in modern data engineering workflows, fostering a community-driven
  ecosystem with extensive documentation, guides, and community support.
url: https://raw.githubusercontent.com/api-evangelist/project-nessie/refs/heads/main/apis.yml
x-type: company
x-source: harvest:tag-qc
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-13 (modular-v1; was harvest)
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - security
  generated: '2026-11-06'
  method: derived
specificationVersion: '0.20'
created: '2026-10-13'
modified: '2026-10-13'
x-docs-platform: mkdocs
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-17
tags:
- Company
- Open Source
- Data Lake
- Version Control
- Community
tags_raw:
- Company
- OpenSource
- DataLake
- VersionControl
- Community
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgentSkill
  url: skills/_index.yml
- type: AgenticAccess
  url: agentic-access/project-nessie-agentic-access.yml
- type: Spectral
  url: rules/project-nessie-rules.yml
- type: ChangeLog
  url: changelog/project-nessie-changelog.yml
- type: ErrorCatalog
  url: errors/project-nessie-problem-types.yml
- type: Conformance
  url: conformance/project-nessie-conformance.yml
- type: Hosts
  url: hosts/project-nessie-hosts.yml
- type: Vendors
  url: vendors/project-nessie-vendors.yml
- type: Security
  url: https://projectnessie.org/nessie-0-101-3/security/
- type: ChangeLog
  url: https://projectnessie.org/releases/
- type: DomainSecurity
  url: security/project-nessie-domain-security.yml
- type: Website
  url: https://projectnessie.org
- type: Documentation
  url: https://projectnessie.org/guides/
- type: APIReference
  url: https://projectnessie.org/develop/rest/
- type: GettingStarted
  url: https://projectnessie.org/guides/try-nessie/
- type: Blog
  url: https://projectnessie.org/blog/
- type: Community
  url: https://projectnessie.org/community/
- type: SourceCode
  url: https://github.com/projectnessie/nessie
apis:
- aid: project-nessie:project-nessie-config-api
  name: Project Nessie Config API
  description: The Config API from Project Nessie — 1 operation(s) for config.
  humanURL: https://projectnessie.org/develop/rest/
  baseURL: https://api.projectnessie.org
  tags:
  - Config
  properties:
  - type: OpenAPI
    url: openapi/project-nessie-config-api-openapi.yml
x-enrichment:
  date: '2026-10-13'
  status: enriched
  artifacts_added: 13
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Project Nessie API — frequently asked questions

Does Project Nessie have an API?

Yes. APIs.io lists 1 API from Project Nessie, including Project Nessie Config API.

Is there an OpenAPI specification for the Project Nessie API?

Yes. APIs.io indexes 1 OpenAPI specification for Project Nessie, each linked for download from this page.

Is the Project Nessie API ready for AI agents?

Project Nessie has a Kin Score of 22.4 out of 100 (emerging) and an Agent Readiness score of 21.7 (agent-aware), scored by API Evangelist on 2026-11-06.

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