Who Is Funded to Build Agent Infrastructure in 2026
The horizontal infrastructure layer for AI agents has emerged as one of the most heavily funded categories in 2025-2026 enterprise AI. The space splits into roughly three sub-categories: durable execution and orchestration (Temporal, Inngest, Restate), observability and evaluation (Braintrust, LangSmith, Helicone, Langfuse, AgentOps), and gateway / proxy (LiteLLM, Helicone's gateway). This page consolidates the funded companies, their rounds, and the category positioning as of May 2026.
Durable Execution and Workflow Orchestration
| Company | Total Funding | Latest Round | Valuation | Notable Customers / Notes |
|---|---|---|---|---|
| Temporal | ~$430M cumulative | $300M Series D (Feb 2026) | $5 billion | Led by a16z; 380% YoY revenue growth; 20M+ monthly installs |
| Inngest | ~$34M cumulative | $20.5M (May 2025) | Undisclosed | Notable Capital + a16z; shipped Temporal-compatible workflows in Feb 2026 |
| Restate | ~$7M cumulative | $7M seed | Undisclosed | Lightweight workflows-as-code; launched commercially March 2026 |
Observability and Evaluation
| Company | Total Funding | Latest Round | Valuation | Notable Customers / Notes |
|---|---|---|---|---|
| Braintrust | ~$120M cumulative | $80M Series B | $800 million | Iconiq + a16z + Greylock; customers Notion, Replit, Cloudflare, Ramp, Dropbox |
| LangSmith (LangChain Inc) | Part of LangChain Inc raises (~$125M+ cumulative) | Latest LangChain round | Undisclosed | Native observability for LangChain / LangGraph stacks |
| Helicone | ~$10M cumulative | Seed-to-Series-A range | Undisclosed | Open-source AI gateway + observability; YC alumnus |
| Langfuse | Acquired | Acquired by ClickHouse Jan 2026 | Part of ClickHouse $400M Series D ($15B) | Open-source code still maintained; community active |
| AgentOps | ~$2.6M | Seed | Undisclosed | 645 Ventures + Afore Capital + Plug and Play; partnered with Red Hat |
| Arize Phoenix | Part of Arize AI cumulative ~$100M+ | Series C | Undisclosed | Open-source observability inside Arize's larger MLOps platform |
Gateway and Proxy
| Company | Total Funding | Notable Detail |
|---|---|---|
| LiteLLM (BerriAI) | ~$15M (seed + Series A) | ~418M monthly PyPI downloads; OpenAI-compatible multi-vendor proxy |
| Portkey | ~$10M | Gateway + observability hybrid; strong APAC presence |
| OpenRouter | Bootstrapped / undisclosed | Multi-model aggregation; profitable |
Six Things the Infrastructure Landscape Tells You
- Durable execution is the highest-funded sub-category. Temporal's $5B valuation after a $300M Series D in Feb 2026 anchors the category. Inngest and Restate are the smaller challengers. The thesis: in-memory agent state (LangGraph) breaks in production; durable execution is the production architecture.
- Observability is consolidating. Langfuse was acquired by ClickHouse in January 2026 (part of ClickHouse's $400M Series D at $15B valuation). The pattern echoes earlier observability consolidation cycles (Datadog acquiring multiple smaller players). Expect more acquisitions through 2026-2027 as larger DevOps platforms move into agent observability.
- Braintrust is the funded leader in evaluation. $80M Series B at $800M valuation with marquee AI-native customers (Notion, Replit, Cloudflare, Ramp, Dropbox) makes Braintrust the category benchmark. LangSmith competes on LangChain-stack lock-in; Helicone competes on open-source positioning.
- LiteLLM monetisation is the open question. 418M monthly PyPI downloads positions LiteLLM as the most-deployed agent-infra component, but commercial monetisation lags adoption substantially. The team has raised modest capital and the path to revenue at scale is the structural question.
- YC alumni dominate observability. Helicone, AgentOps, and several smaller observability startups are YC alumni. The pattern reflects observability being a developer-tools category with predictable bottom-up adoption motion that YC-style growth fits well.
- Cross-category convergence is happening. Helicone (gateway + observability), Braintrust (observability + evaluation), Inngest (durable execution + observability) all span multiple sub-categories. Expect further blurring; the pure-play categories will narrow as platforms expand horizontally.
What This Means for AI Visibility
Agent infrastructure startups themselves are AI-visibility-relevant in two ways. First, brand-visibility programmes selling to AI-native companies need to surface inside the agent stacks these companies run on; visibility on Braintrust, Helicone, and Temporal dashboards (via integrations and partner programs) matters disproportionately for developer-tool brands. Second, the agent infrastructure layer is itself a customer category buying B2B products; brands selling into the infra-startup buyer (logging, observability adjacencies, payment processing, cloud) should track their visibility within that buyer segment.
Methodology
Funding and valuation data collected May 15, 2026 from Crunchbase, PitchBook, vendor press releases, and TechCrunch / Yahoo Finance / SiliconANGLE coverage of the major rounds. Customer lists from public case studies on vendor websites. Refreshed quarterly as the category continues to consolidate.
How Presenc AI Helps
Presenc AI tracks brand-mention rates inside AI-native company deployments. When a brand sells products that integrate with Temporal, Braintrust, Helicone, or other infra-layer products, our instrumentation captures visibility inside those buyer demographics. For brands selling to the agent infrastructure layer or building products that depend on it, this is the operational signal that connects developer-tool visibility to revenue.