Agent harness testing and observability for reliable LLM apps

Agent harness testing and observability for reliable LLM apps targets a $5.0B = 100,000 organizations building production LLM apps x $50K ACV. Rationale: tens of thousands of orgs across startups and enterprises are adding agentized features; a mid-market/enterprise ACV of roughly $50K is realistic for org-wide observability and testing tooling. total addressable market with medium saturation and a year-over-year growth rate of 35-50% growth in teams building production LLM agents, driven by SDKs and cloud hosted model APIs.

Key trends driving demand: Agentization of features -- teams are replacing single-call prompts with multi-step agents, increasing brittleness and need for harnessing; LLM observability demand -- as models get integrated into production, teams require logging, traces, and behavior diffs similar to traditional APM; SDK consolidation -- widespread adoption of LangChain, Semantic Kernel, and similar SDKs creates a standardized integration point for harness products; Function and tool-calling features -- model-level tool invocation creates new deterministic failure modes that standard unit tests miss.