# Pi Labs

**Canonical:** https://apis.io/providers/pi-labs/  
**Website:** https://withpi.ai  
**APIs profiled:** 1

Pi Labs (withpi.ai) is an applied-AI company, backed by Accel and later acquired by Microsoft, that builds tooling to evaluate and enhance AI applications. Its core product, Pi Scorer, is a deterministic, roughly 200ms foundation model that scores any text against a rubric of natural-language questions — reported to be about 500x more efficient than using an LLM as a judge. Teams use it to calibrate rubrics, gate and rank LLM outputs, and close the loop across training, inference, and feedback. The scoring engine is exposed as an OpenAPI-compatible REST API at api.withpi.ai with official Python and TypeScript SDKs (both published as "withpi"), a copilot for building scoring specs, and a Promptfoo integration (Pi Scorer).

## Kin Score — 16.9 / 100 (emerging)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 16.9).

| Facet | Score |
|---|---|
| Discoverability | 75.9 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 10.5 |
| Developer Ergonomics | 39.9 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

## Agent readiness — 9.6 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Self-serve signup — onboarding: self-serve, pricing: unknown, trial: no (confidence: medium).

## APIs (1)

- **Pi Scoring API** — OpenAPI-compatible REST API for scoring, calibrating, and optimizing LLM outputs against rubrics of natural-language questions. Authenticated with an API key (WITHPI_API_KEY) se...

## Security (1)

- **Pi Labs Authentication** — apiKey · 1 scheme

## Tags

Company, Artificial Intelligence, Evaluation, LLM, Scoring, Machine-Learning, Developer Tools

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/pi-labs/). Scores are computed from the provider's own public artifacts under a published rubric.