Kosmoy vs Braintrust: LLM Evaluation and Governance Compared (2026)
Braintrust is one of the strongest LLM evaluation tools for AI product engineers. Kosmoy is an AI management platform with evaluation and red teaming built in. One is where you author and run evals; the other is where the enterprise governs, enforces and proves.
Alejo HernandezCTO, KosmoyBraintrust and Kosmoy both help teams ship AI they can trust, but they aim at different buyers. Braintrust made evaluation a first-class engineering discipline — a code-first `Eval()` primitive, datasets, experiments, a prompt playground and production online scoring — and rode it to an $80M Series B at an $800M valuation in February 2026, with Notion, Stripe and Zapier as customers. Kosmoy is the platform an enterprise wraps around its AI: an inventory of every system, a gateway that enforces policy, a sandbox for agents that act, compliance evidence for auditors — and, since 2026, its own evaluation and red-teaming suite.
This page compares the two honestly, axis by axis, with every Braintrust claim cited. The short version: Braintrust is the deeper evaluation-authoring tool, and this page says so; Kosmoy wins where evaluation has to connect to enforcement, inventory, containment and audit evidence, in your own infrastructure.
Who each product is for
Braintrust
Braintrust speaks to AI product engineers. Its code-first `Eval()` primitive, datasets, experiments, prompt playground, the Loop agent and production online scoring make evaluation a fast, iterative part of the build loop — the reason it counts Notion, Stripe, Airtable and Zapier as customers and raised at an $800M valuation in February 2026.
Its buyer is the engineer shipping an LLM feature who wants to know, quantitatively, whether the new prompt or model is better than the last. On pure evaluation authoring it is among the strongest tools in the category.
Kosmoy
Kosmoy speaks to the people accountable for AI as a whole: CTOs, CISOs and AI governance leads in regulated industries. Its unit of work is the AI system — registered with an owner and a risk tier, enforced through the gateway, tested by the built-in evaluation and red-teaming suite, and, where it acts, contained in an Action Capsule.
It is a full platform you run single-tenant in your own Kubernetes, air-gap capable — in production at Italy's central bank and banking regulator and Europe's largest defence and aerospace group.
The capability radar
Each spoke is one capability, scored 0–10. Braintrust peaks sharply on one: Testing, Evals & Red-teaming 9 to Kosmoy's 7, and it is strong on Observability (8) too. Everywhere else its shape is narrow by design — no gateway, guardrails, inventory, containment or compliance tooling — while Kosmoy's is the wide web, scoring 10 on sovereignty as self-hosted-only software.
- Braintrust
- Kosmoy
| Capability (0–10) | Braintrust | Kosmoy | Notes on Braintrust |
|---|---|---|---|
| AI Inventory & Discovery | 1 | 9 | Projects and experiments live inside the workspace; no org-wide registry. |
| Security & Shadow AI | 1 | 8 | SSO, RBAC and SOC 2; no AI-specific security posture product. |
| Observability & FinOps | 8 | 7 | Brainstore built for million-token agent traces; online scoring; Topics pattern clustering. |
| Gateway & Policy Control | 3 | 8 | The open-source AI Proxy unifies providers with caching and key management, but enforces no policy on traffic. |
| Guardrails & Runtime Safety | 1 | 8 | Scorers run asynchronously as online evals; no runtime blocking. |
| Agent Containment | 0 | 9 | No sandboxing, kill switch or scoped-credential controls documented. |
| Compliance & Audit | 3 | 9 | SOC 2 and a signed BAA on Enterprise; hybrid keeps data in your environment; no AI-regulation tooling. |
| Testing, Evals & Red-teaming | 9 | 7 | Evals-first: Eval() SDK, autoevals, judge and code scorers, human review, and Loop generating evals from traces. |
| Agent Building | 1 | 6 | Loop is an internal eval assistant, not an agent-building product. |
| Deployment Sovereignty | 7 | 10 | Self-hosted data plane (Terraform, Docker, Helm) on Enterprise; the control plane stays Braintrust-hosted — no air gap. |
Bold marks the highest score on each row. 10 is reserved for categorical architectural facts; specialists are expected to outscore platforms on their own spoke.
Where Braintrust wins
Evaluation authoring. Braintrust's code-first `Eval()` workflow, with datasets, experiments and a prompt playground, is among the best eval-authoring experiences in the category — it scores 9 on evals to Kosmoy's 7 (Braintrust). Kosmoy's suite is comprehensive but newer, and Braintrust leads on the iterate-in-code loop.
Dataset and experiment management. Braintrust's dataset curation and experiment comparison are a core strength; Kosmoy manages datasets and numbered runs, but Braintrust's experiment workflow is deeper.
Developer adoption. A free tier and self-serve pricing let a single engineering team adopt Braintrust this afternoon. Kosmoy has no self-service tier; procurement runs through enterprise sales.
Product-engineering focus. Braintrust is built end-to-end for the AI product engineer's inner loop, an ergonomics a governance platform does not match on that specific workflow.
Where Kosmoy wins
Red teaming. Braintrust does not offer red teaming. Kosmoy runs single- and multi-turn adversarial attacks with a policy-compliance judge, per-case remediation and a false-refusal rate (AI Red Teaming) — a capability Braintrust simply does not have.
A gateway that enforces. Braintrust scores; it is not in the traffic path. Kosmoy's AI Gateway is one OpenAI-compatible policy point across LLM, MCP and A2A calls, with RBAC, routing, budgets and guardrails on every request — where a finding becomes an enforced rule.
Inventory and shadow AI. Braintrust sees the projects you evaluate in it. Kosmoy's four registries inventory every AI system, model, MCP server and agent — including external agents from Foundry, Bedrock, Vertex, Salesforce and ServiceNow — each with an owner and a risk tier.
Agent containment. Braintrust has no runtime containment. Kosmoy's Action Capsule sandboxes agents, MCP servers and private models with per-task credentials and a kill switch.
Compliance evidence and sovereignty. Braintrust documents SOC 2 for itself but no EU AI Act, ISO/IEC 42001 or NIST AI RMF tooling, and it is a US-cloud SaaS. Kosmoy produces framework-ready evidence and runs single-tenant in your own Kubernetes, air-gapped if needed — sovereignty scored 10.
Deployment and pricing model
| Braintrust | Kosmoy | |
|---|---|---|
| Primary shape | LLM evaluation & observability platform for product teams | AI management platform with evaluation and red teaming built in |
| Red teaming | Not offered | Single- and multi-turn, judged, with remediation |
| Enforcement | Scores and reports; no runtime policy point | Findings become enforced gateway guardrails |
| Hosting model | SaaS (US cloud); enterprise options | Self-hosted only — single-tenant, your own Kubernetes, air-gap capable |
| Compliance evidence | SOC 2 for itself; no EU AI Act / ISO 42001 / NIST AI RMF tooling documented | EU AI Act, ISO/IEC 42001 (aligned), NIST AI RMF evidence bundles |
| Pricing model | Free tier; Pro self-serve; Enterprise by quote | Enterprise subscription; no self-service tier |
Last verified July 31, 2026 against each vendor's public documentation.
Running them together
Braintrust and Kosmoy occupy different layers and coexist well. Engineers author and run evals in Braintrust during the build loop, iterating on prompts and models with its datasets and experiments; Kosmoy governs the path to production — inventory, gateway enforcement, red teaming against the deployed assistant, containment and compliance evidence. Because Kosmoy's own evaluation reads gateway traffic rather than requiring Braintrust's SDK, the two eval stories complement rather than collide. If the requirement is one self-hosted platform that evaluates, red-teams and enforces in your perimeter, that is Kosmoy; if it is the best eval-authoring experience for engineers, keep Braintrust.
Questions buyers ask
Is Kosmoy better than Braintrust?
Not for authoring and running evals — Braintrust is the deeper tool there, scoring 9 on evals to Kosmoy's 7, with a best-in-class code-first eval workflow and experiment management. Kosmoy is the stronger platform where governance is the requirement: red teaming (which Braintrust does not offer), gateway-enforced policy, organization-wide inventory, agent containment and EU AI Act / ISO 42001 evidence, with its own evaluation wired in. Product engineers should shortlist Braintrust; regulated enterprises proving control should shortlist Kosmoy.
Does Braintrust do red teaming?
No — Braintrust focuses on evaluation and observability and does not offer native red teaming as of July 2026. Kosmoy includes it: single- and multi-turn adversarial attacks against the deployed assistant, scored by a policy-compliance judge with per-case remediation and a false-refusal rate, mapped to the OWASP LLM Top 10. Teams on Braintrust that need adversarial testing pair it with a red-teaming tool; Kosmoy covers evaluation and red teaming in one platform.
Can Braintrust help with EU AI Act compliance?
Braintrust provides evaluation and production scoring that support a compliance program and holds SOC 2, but it does not document EU AI Act, ISO/IEC 42001 or NIST AI RMF evidence generation or risk classification as of July 2026, and it is a US-cloud SaaS. Kosmoy generates framework-mapped evidence from its registry, gateway logs and evaluation runs, self-hosted in your own infrastructure — a core product difference for regulated buyers.
Which is better for a regulated enterprise?
Kosmoy, in most cases: single-tenant in the enterprise's own Kubernetes (including air-gapped), risk-tiering every AI system, enforcing policy at a gateway, red-teaming the deployed system, and producing auditor-ready evidence. Braintrust is the stronger eval-authoring tool, but it offers no red teaming, no enforcement and no compliance evidence, and its data lives in a US cloud. Italy's central bank and banking regulator runs Kosmoy in production.
Can I run Braintrust and Kosmoy together?
Yes. Engineers author and run evals in Braintrust during development; Kosmoy governs production — inventory, gateway enforcement, red teaming, containment and compliance evidence — and evaluates production traffic gateway-natively without a separate SDK. The build-loop evals stay in Braintrust; the governed runtime, red teaming and evidence stay in Kosmoy.
Sources
Every factual claim about another vendor on this page traces to that vendor's own published material or a named third-party source below.
- Braintrust — Series B announcement — accessed July 31, 2026
- Braintrust pricing — accessed July 31, 2026
- Kosmoy AI Evaluation & Red Teaming — accessed July 31, 2026
- Kosmoy AI Compliance — accessed July 31, 2026
- Platform architecture docs (hybrid data plane) — accessed July 15, 2026
- Plans and limits — accessed July 15, 2026
- AI Proxy repository (MIT) — accessed July 15, 2026
- SiliconANGLE — Braintrust $80M Series B (Feb 2026) — accessed July 15, 2026
See the platform behind the scores
Kosmoy puts an inventory, a policy gateway and a containment sandbox around every AI your teams run — in your own Kubernetes.
Or email sales@kosmoy.com.