# Cumulus Labs

**Canonical:** https://apis.io/providers/cumulus-labs/  
**Website:** https://cumuluslabs.io/  
**APIs profiled:** 1

Cumulus Labs is a Y Combinator (W26) company building a unified inference platform for production AI. Cumulus consolidates the eight subsystems teams normally assemble from separate vendors — an OpenAI-compatible gateway, a per-workflow router, a layered prompt/KV cache, request-level observability, continuous shadow evaluation, one-click LoRA fine-tuning, custom open-weight hosting, and the proprietary Ion inference engine running on NVIDIA Grace and Blackwell GPUs — behind a single OpenAI-compatible API at api.cumuluslabs.io/v1. Ion's custom attention kernels deliver 30-50% more throughput than stock vLLM and SGLang, and the gateway is a drop-in replacement for the OpenAI, Anthropic, LangChain, LlamaIndex, and Vercel AI SDKs — change one line of configuration and keep your existing code.

## Kin Score — 24.4 / 100 (emerging)

Scored 2026-08-17 under rubric 0.11.0. Trend: flat (+0.0 from 24.4).

| Facet | Score |
|---|---|
| Discoverability | 75.9 |
| Contract Quality | 0.0 |
| Governance | 12.5 |
| Operational Transparency | 5.3 |
| Developer Ergonomics | 52.2 |
| Commercial Clarity | 21.1 |

## Agent readiness — 9.0 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | 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 | no |
| 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)

- **Cumulus Inference Gateway** — OpenAI-compatible HTTP inference gateway. One client works against every upstream provider; per-workflow routing rules pick the model, provider, and infrastructure, with a layer...

## Security (2)

- **Cumulus Labs Authentication** — http · 1 scheme
- **Cumulus Labs Domain Security** — TLSv1.3 · DNSSEC · DMARC

## Tags

Company, Inference, LLM, AI Infrastructure, GPU, Machine Learning, Model Serving, Fine-Tuning, API Gateway, Y Combinator

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