Sapien

Sapien is the company behind Proof of Quality (PoQ), an open protocol and consensus/attestation system for verifiable quality signals on AI data and subjective expert outputs. A panel of independent, collateral-backed validators reviews each item against a customer-defined rubric (a poq.toml spec), consensus collapses their scores into one rating per datapoint, and the result is sealed as a permanent onchain attestation (a PoQ Report) — while the underlying data never leaves the customer's systems. Use cases span training-data labeling, fine-tuning and evaluation gates, audit/compliance review, and production safety verification. Sapien ships a live Developer API (/developer/v1) and an MCP server, both authenticated with poq_live_ API keys, and runs on Base Mainnet with a $SAPIEN staking/slashing token. Backed by General Catalyst.

Sapien publishes 5 APIs on the APIs.io network, including Datapoints API, Projects API, System API, and 2 more. Tagged areas include Company, Artificial Intelligence, Data Quality, Data Labeling, and Machine Learning.

Sapien’s developer surface includes authentication, documentation, getting-started guide, engineering blog, signup flow, and 18 more developer resources.

🌐 Visit website 📡 Source on GitHub

39.2/100 thin ▬ flat Agent 33/100 agent ready saas Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

1 APIs 1 MCP Servers

Company Artificial Intelligence Data Quality Data Labeling Machine Learning Human-in-the-Loop Attestation Blockchain Consensus MCP

Kin Score

Kin Score How this is scored →
scored 2026-09-25 · rubric v0.23.0

Composite quality — 39.2/100 · thin

Contract Quality 8.3 / 19

Developer Ergonomics 8.1 / 15

Access Clarity 5.1 / 15

Operational Transparency 0.8 / 10

Contract Governance 0.4 / 9

Discoverability 5.6 / 8

Regulatory Posture 3.4 / 15

Create-or-Update Ergonomics 1.1 / 10

Agent readiness — 33/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 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 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 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 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/sapien: 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.

Sapien Datapoints API

The Datapoints API from Sapien — 1 operation(s) for datapoints.

Sapien Projects API

The Projects API from Sapien — 2 operation(s) for projects.

Sapien System API

The System API from Sapien — 1 operation(s) for system.

Sapien Upload Sessions API

The Upload Sessions API from Sapien — 6 operation(s) for upload sessions.

Sapien Validators API

The Validators API from Sapien — 9 operation(s) for validators.

Open Collections 6

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

API Collection

OPEN COLLECTION

Sapien Developer Datapoints API

OPEN COLLECTION

Sapien Developer Datapoints Projects API

OPEN COLLECTION

Sapien Developer Datapoints System API

OPEN COLLECTION

Sapien Developer Datapoints Upload Sessions API

OPEN COLLECTION

Sapien Developer Datapoints Validators API

OPEN COLLECTION

MCP Servers 1

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

Sapien MCP Server

MCP SERVER

Security Posture 2

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

Sapien Authentication

http · 1 scheme

SECURITY

Sapien Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Sapien Agentic Access

22 operations · 12 acting · 1 human-in-the-loop

22 operations · 12 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

MCPServer

LLMsTxt

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions

Idempotency

ErrorCatalog

Conformance

Lifecycle

DataModel

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

Roadmap

Roadmap

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Blog

Blog

Website

Website

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: sapien
name: Sapien
description: Sapien is the company behind Proof of Quality (PoQ), an open protocol and consensus/attestation system for verifiable
  quality signals on AI data and subjective expert outputs. A panel of independent, collateral-backed validators reviews each
  item against a customer-defined rubric (a poq.toml spec), consensus collapses their scores into one rating per datapoint,
  and the result is sealed as a permanent onchain attestation (a PoQ Report) — while the underlying data never leaves the
  customer's systems. Use cases span training-data labeling, fine-tuning and evaluation gates, audit/compliance review, and
  production safety verification. Sapien ships a live Developer API (/developer/v1) and an MCP server, both authenticated
  with poq_live_ API keys, and runs on Base Mainnet with a $SAPIEN staking/slashing token. Backed by General Catalyst.
url: https://raw.githubusercontent.com/api-evangelist/sapien/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://docs.sapien.io/favicon.jpg
x-type: company
x-source: vc-portfolio
x-backed-by:
- general-catalyst
x-tier: active
x-tier-reason: enriched-has-api
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- Artificial Intelligence
- Data Quality
- Data Labeling
- Machine Learning
- Human-in-the-Loop
- Attestation
- Blockchain
- Consensus
- MCP
tags_raw:
- Company
- AI
- Data Quality
- Data Labeling
- Machine Learning
- Human in the Loop
- Attestation
- Blockchain
- Consensus
- MCP
- Machine-Learning
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: sapien:sapien-datapoints-api
  name: Sapien Datapoints API
  description: The Datapoints API from Sapien — 1 operation(s) for datapoints.
  humanURL: https://docs.sapien.io/integrate/developer-api
  baseURL: https://sapien-poq.up.railway.app/developer/v1
  tags:
  - Datapoints
  properties:
  - type: OpenAPI
    url: openapi/sapien-datapoints-api-openapi.yml
  - type: APIReference
    url: https://sapien-poq.up.railway.app/developer/v1/docs
  - type: Documentation
    url: https://docs.sapien.io/integrate/developer-api
- aid: sapien:sapien-projects-api
  name: Sapien Projects API
  description: The Projects API from Sapien — 2 operation(s) for projects.
  humanURL: https://docs.sapien.io/integrate/developer-api
  baseURL: https://sapien-poq.up.railway.app/developer/v1
  tags:
  - Project
  tags_raw:
  - Projects
  properties:
  - type: OpenAPI
    url: openapi/sapien-projects-api-openapi.yml
  - type: APIReference
    url: https://sapien-poq.up.railway.app/developer/v1/docs
  - type: Documentation
    url: https://docs.sapien.io/integrate/developer-api
- aid: sapien:sapien-system-api
  name: Sapien System API
  description: The System API from Sapien — 1 operation(s) for system.
  humanURL: https://docs.sapien.io/integrate/developer-api
  baseURL: https://sapien-poq.up.railway.app/developer/v1
  tags:
  - System
  properties:
  - type: OpenAPI
    url: openapi/sapien-system-api-openapi.yml
  - type: APIReference
    url: https://sapien-poq.up.railway.app/developer/v1/docs
  - type: Documentation
    url: https://docs.sapien.io/integrate/developer-api
- aid: sapien:sapien-upload-sessions-api
  name: Sapien Upload Sessions API
  description: The Upload Sessions API from Sapien — 6 operation(s) for upload sessions.
  humanURL: https://docs.sapien.io/integrate/developer-api
  baseURL: https://sapien-poq.up.railway.app/developer/v1
  tags:
  - Upload Sessions
  properties:
  - type: OpenAPI
    url: openapi/sapien-upload-sessions-api-openapi.yml
  - type: APIReference
    url: https://sapien-poq.up.railway.app/developer/v1/docs
  - type: Documentation
    url: https://docs.sapien.io/integrate/developer-api
- aid: sapien:sapien-validators-api
  name: Sapien Validators API
  description: The Validators API from Sapien — 9 operation(s) for validators.
  humanURL: https://docs.sapien.io/integrate/developer-api
  baseURL: https://sapien-poq.up.railway.app/developer/v1
  tags:
  - Validator
  tags_raw:
  - Validators
  properties:
  - type: OpenAPI
    url: openapi/sapien-validators-api-openapi.yml
  - type: APIReference
    url: https://sapien-poq.up.railway.app/developer/v1/docs
  - type: Documentation
    url: https://docs.sapien.io/integrate/developer-api
common:
- type: DomainSecurity
  url: security/sapien-domain-security.yml
- type: AgenticAccess
  url: agentic-access/sapien-agentic-access.yml
- type: Authentication
  url: authentication/sapien-authentication.yml
- type: MCPServer
  url: mcp/sapien-mcp.yml
- type: LLMsTxt
  url: llms/sapien-llms.txt
- type: Conventions
  url: conventions/sapien-conventions.yml
- type: Idempotency
  url: conventions/sapien-conventions.yml
- type: ErrorCatalog
  url: errors/sapien-problem-types.yml
- type: Conformance
  url: conformance/sapien-conformance.yml
- type: Lifecycle
  url: lifecycle/sapien-lifecycle.yml
- type: DataModel
  url: data-model/sapien-data-model.yml
- type: Overlay
  url: overlays/sapien-poq-overlay.yaml
- type: AgentSkill
  url: skills/_index.yml
- type: DeveloperPortal
  url: https://www.sapien.io/developers
- type: Documentation
  url: https://docs.sapien.io/
- type: GettingStarted
  url: https://docs.sapien.io/start/quickstart
- type: GitHubOrganization
  url: https://github.com/sapien-io
- type: Blog
  url: https://www.sapien.io/blog
- type: Roadmap
  url: https://www.sapien.io/roadmap
- type: SignUp
  url: https://www.sapien.io/developers
- type: TermsOfService
  url: https://www.sapien.io/terms-of-service
- type: PrivacyPolicy
  url: https://www.sapien.io/privacy-policy
- type: Website
  url: https://www.sapien.io
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 13
  pass: local-v1

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