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, AI, 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
43.5/100 thin ▬ flat Agent 74/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
5 APIs 1 MCP Servers
CompanyAIData QualityData LabelingMachine LearningHuman in the LoopAttestationBlockchainConsensusMCP

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 43.5/100 · thin
Contract Quality 14.0 / 25
Developer Ergonomics 11.3 / 20
Commercial Clarity 6.8 / 20
Operational Transparency 1.4 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 74/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
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
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/sapien: 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 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.

MCP Servers 1

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

sapien-mcp.yml

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
AgenticAccess
 MCPServer
MCPServer
 LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 Idempotency
Idempotency
 ErrorCatalog
ErrorCatalog
 Conformance
Conformance
 Lifecycle
Lifecycle
 DataModel
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)

apis.yml Raw ↑ 
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
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://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: '0.20'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- AI
- Data Quality
- Data Labeling
- Machine Learning
- Human in the Loop
- Attestation
- Blockchain
- Consensus
- MCP
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:
  - 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:
  - 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