Understudy Labs

Understudy Labs (YC S26) is an LLM gateway and model-optimization platform that helps teams move repeated production LLM workloads onto open-weight models they own. The Understudy gateway is a drop-in replacement for the Anthropic and OpenAI API endpoints that captures request/response traces by project and workload, routes measured slices of traffic to managed open models, and falls back safely. A REST control plane manages keys, projects, workloads, routing, captures, evaluation cohorts, and reporting, while the MIT-licensed understudy-agent-tools repo ships a CLI, a coding-agent skill library, a local MCP server, and Understudy Desktop with a documented loopback OpenAPI 3.1 contract.

Understudy Labs publishes 10 APIs on the APIs.io network, including Capabilities API, Conversations API, Downloads API, and 7 more. Tagged areas include Artificial Intelligence, LLM Gateway, Machine-Learning, Open-Source, and Model Routing.

Understudy Labs’ developer surface includes authentication, documentation, API reference, getting-started guide, support, engineering blog, CLI, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub

47.4/100 developing ▬ flat Agent 40/100 agent ready Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

AccessSelf serve

12 APIs 1 MCP Servers

Artificial IntelligenceLLM GatewayMachine-LearningOpen-SourceModel RoutingEvaluationsFine-TuningAI InfrastructureDeveloper Tools

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 47.4/100 · developing

Contract Quality 12.3 / 25

Developer Ergonomics 14.3 / 20

Access Clarity 5.5 / 20

Operational Transparency 2.4 / 13

Contract Governance 3.6 / 12

Discoverability 9.3 / 10

Agent readiness — 40/100 · 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 0 / 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

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/understudy-labs: 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 12

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

Open Collections 11

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

MCP Servers 1

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

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

LLMsTxt

WellKnown

MCPServer

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

ErrorCatalog

Conventions

Lifecycle

Conformance

DataModel

Arazzo

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

CLI

CLI

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

Support

Support

ChangeLog

ChangeLog

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: understudy-labs
name: Understudy Labs
description: Understudy Labs (YC S26) is an LLM gateway and model-optimization platform that helps teams move repeated production
  LLM workloads onto open-weight models they own. The Understudy gateway is a drop-in replacement for the Anthropic and OpenAI
  API endpoints that captures request/response traces by project and workload, routes measured slices of traffic to managed
  open models, and falls back safely. A REST control plane manages keys, projects, workloads, routing, captures, evaluation
  cohorts, and reporting, while the MIT-licensed understudy-agent-tools repo ships a CLI, a coding-agent skill library, a
  local MCP server, and Understudy Desktop with a documented loopback OpenAPI 3.1 contract.
url: https://raw.githubusercontent.com/api-evangelist/understudy-labs/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://bookface-images.s3.amazonaws.com/small_logos/034b1bab6d92bd99439aee47bf2312630046798c.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- y-combinator
x-tier: profile
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Artificial Intelligence
- LLM Gateway
- Machine-Learning
- Open-Source
- Model Routing
- Evaluations
- Fine-Tuning
- AI Infrastructure
- Developer Tools
tags_raw:
- Artificial Intelligence
- LLM Gateway
- Machine Learning
- Open Source
- Model Routing
- Evaluations
- Fine-Tuning
- AI Infrastructure
- Developer Tools
apis:
- aid: understudy-labs:understudy-gateway-api
  name: Understudy Gateway API
  description: Anthropic- and OpenAI-compatible LLM proxy at api.understudylabs.com. POST /v1/messages (Anthropic Messages),
    POST /v1/chat/completions (OpenAI Chat Completions), POST /v1/messages/count_tokens, GET /v1/models (public managed-model
    catalog), and GET /healthz. Supports bring-your-own-key passthrough and managed catalog models, capture of request/response
    evidence, canary routing with fallback, and x-understudy-* scoping, tagging, and legibility headers.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - LLM Gateway
  - Proxy
  - Model Routing
  properties:
  - type: Documentation
    url: https://docs.understudylabs.com/reference/proxy-endpoints
  - type: APIReference
    url: https://docs.understudylabs.com/reference/request-headers
- aid: understudy-labs:understudy-control-plane-api
  name: Understudy Control Plane API
  description: REST surface behind the dashboard and CLI, served from the gateway host under /admin/v1 and /customer/v1, org-scoped
    and authenticated with sk_* bearer keys. Covers API key mint/list/revoke, project CRUD by slug, workload CRUD, the model
    catalog, route writes with traffic percentages, capture listing and envelope fetch, evaluation capture catalogs with frozen
    cohorts and audited short-lived exports, and reporting endpoints for routing status, provider health, workload status,
    and usage summaries.
  humanURL: https://docs.understudylabs.com/reference/control-plane
  baseURL: https://api.understudylabs.com
  tags:
  - Control Plane
  - APIKeys
  - Routing
  - Evaluations
  tags_raw:
  - Control Plane
  - API Keys
  - Routing
  - Evaluations
  properties:
  - type: Documentation
    url: https://docs.understudylabs.com/reference/control-plane
  - type: APIReference
    url: https://docs.understudylabs.com/reference/control-plane/keys
- aid: understudy-labs:understudy-labs-capabilities-api
  name: Understudy Labs Capabilities API
  description: The Capabilities API from Understudy Labs — 1 operation(s) for capabilities.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Capabilities
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-capabilities-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-conversations-api
  name: Understudy Labs Conversations API
  description: The Conversations API from Understudy Labs — 1 operation(s) for conversations.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Conversations
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-conversations-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-downloads-api
  name: Understudy Labs Downloads API
  description: The Downloads API from Understudy Labs — 3 operation(s) for downloads.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Downloads
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-downloads-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-feedback-api
  name: Understudy Labs Feedback API
  description: The Feedback API from Understudy Labs — 1 operation(s) for feedback.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Feedback
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-feedback-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-metrics-api
  name: Understudy Labs Metrics API
  description: The Metrics API from Understudy Labs — 1 operation(s) for metrics.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Metrics
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-metrics-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-models-api
  name: Understudy Labs Models API
  description: The Models API from Understudy Labs — 2 operation(s) for models.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Models
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-models-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-residency-api
  name: Understudy Labs Residency API
  description: The Residency API from Understudy Labs — 6 operation(s) for residency.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Residency
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-residency-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-runs-api
  name: Understudy Labs Runs API
  description: The Runs API from Understudy Labs — 2 operation(s) for runs.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Runs
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-runs-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-status-api
  name: Understudy Labs Status API
  description: The Status API from Understudy Labs — 1 operation(s) for status.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Status
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-status-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
- aid: understudy-labs:understudy-labs-supervision-api
  name: Understudy Labs Supervision API
  description: The Supervision API from Understudy Labs — 1 operation(s) for supervision.
  humanURL: https://docs.understudylabs.com/reference/proxy-endpoints
  baseURL: https://api.understudylabs.com
  tags:
  - Supervision
  properties:
  - type: OpenAPI
    url: openapi/understudy-labs-supervision-api-openapi.yml
  - type: Documentation
    url: https://docs.understudylabs.com/open-source/desktop-task-models
common:
- type: Overlay
  url: overlays/understudy-labs-desktop-api-overlay.yaml
- type: AgenticAccess
  url: agentic-access/understudy-labs-agentic-access.yml
- type: Authentication
  url: authentication/understudy-labs-authentication.yml
- type: DomainSecurity
  url: security/understudy-labs-domain-security.yml
- type: Website
  url: https://understudylabs.com
- type: DeveloperPortal
  url: https://docs.understudylabs.com
- type: Documentation
  url: https://docs.understudylabs.com
- type: APIReference
  url: https://docs.understudylabs.com/reference/proxy-endpoints
- type: GettingStarted
  url: https://docs.understudylabs.com/quickstart
- type: Login
  url: https://app.understudylabs.com
- type: Support
  url: https://understudylabs.com/contact
- type: Blog
  url: https://understudylabs.com/research
- type: GitHubOrganization
  url: https://github.com/understudylabs
- type: TermsOfService
  url: https://understudylabs.com/terms
- type: PrivacyPolicy
  url: https://understudylabs.com/privacy
- type: LLMsTxt
  url: llms/understudy-labs-llms.txt
- type: WellKnown
  url: well-known/understudy-labs-well-known.yml
- type: MCPServer
  url: mcp/understudy-labs-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: ErrorCatalog
  url: errors/understudy-labs-problem-types.yml
- type: Conventions
  url: conventions/understudy-labs-conventions.yml
- type: Lifecycle
  url: lifecycle/understudy-labs-lifecycle.yml
- type: Conformance
  url: conformance/understudy-labs-conformance.yml
- type: Packages
  url: packages/understudy-labs-packages.yml
- type: CLI
  url: cli/understudy-labs-cli.yml
- type: ChangeLog
  url: changelog/understudy-labs-changelog.yml
- type: DataModel
  url: data-model/understudy-labs-data-model.yml
- type: Arazzo
  url: arazzo/understudy-labs-download-warm-and-chat.yml
  name: Download, warm, and chat with a local model on Understudy Desktop
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 24
  pass: local-v1