AgentX 1.0 Brings Realism to Inference Benchmarks
SemiAnalysis released AgentX 1.0, an Apache 2.0 open-source benchmark built from agentic coding traces representing more than $3M in API spend. It replays 393 multi-turn Claude Code sessions with contexts up to 1 million tokens, prefix reuse, timing, and subagent activity.
AgentX is a meaningful upgrade for inference benchmarking because it tests the workload shape modern coding agents actually create, not isolated prompt-and-response throughput.
- –Replaces fixed-sequence tests with closed-loop sessions featuring growing context, KV-cache reuse, tool delays, and parallel subagents.
- –The 393-session dataset has a 142k-token median input and 44% subagent participation, stressing cache capacity, offload bandwidth, scheduling, and routing.
- –Privacy-preserving synthetic payloads retain workload structure without exposing original prompts, code, or tool results.
- –AgentX measures serving performance—not coding correctness—so teams should pair it with task benchmarks such as SWE-bench.
- –Its common methodology gives vLLM, SGLang, and other stacks a reproducible target for validating real agentic-inference optimizations.
DISCOVERED
1h ago
2026-08-25
PUBLISHED
3h ago
2026-08-25
RELEVANCE
AUTHOR
vllm_project