diff --git a/benchmarks/single_node/agentic/qwen3.8next_fp8_h200_sglang_mtp.sh b/benchmarks/single_node/agentic/qwen3.8next_fp8_h200_sglang_mtp.sh
new file mode 100755
index 0000000000..5199d539cc
--- /dev/null
+++ b/benchmarks/single_node/agentic/qwen3.8next_fp8_h200_sglang_mtp.sh
@@ -0,0 +1,217 @@
+#!/usr/bin/env bash
+set -euo pipefail
+set -x
+
+# Agentic trace replay benchmark for Qwen3.8-Flash-Next FP8 on H200 using
+# SGLang with MTP speculative decoding. Day-zero recipe; SGLang is the
+# plan-of-record engine for this model (MODELS.md), and it is spec-decode only,
+# per the AgentX policy that new agentic arms ship with speculative decoding
+# enabled rather than as an STP/MTP A/B.
+#
+# H200 is Hopper, so this arm is FP8 (Qwen/Qwen3.8-Flash-Next-FP8, 172.8 GiB at
+# TP8) rather than the NVFP4 checkpoint the Blackwell arms use: NVFP4 needs
+# SM100 tensor cores. Attention backend stays flashinfer (sm_90).
+#
+# Structure follows the proven H100 MTP AgentX replay path
+# (HiCache host-DRAM offload, the multi_tokenizer cached_tokens_details patch,
+# aiperf-driven trace replay). H200's 141 GB HBM3e is roomier than H100's 80 GB,
+# so --mem-fraction-static is 0.8 rather than 0.75, matching
+# fixed_seq_len/qwen3.5_fp8_h200_mtp.sh. Attention backend stays flashinfer
+# (sm_90); the trtllm_mha path is Blackwell-only.
+#
+# Speculative decoding mirrors fixed_seq_len/qwen3.5_fp8_h100_mtp.sh:
+# SGLANG_ENABLE_SPEC_V2=1 with --speculative-algorithm EAGLE, 3 steps, eagle-topk
+# 1 and 4 draft tokens, i.e. 3 speculative tokens per verification step.
+#
+# Throughput runs pin acceptance to the committed golden AL through SGLang's
+# simulated-acceptance path; the EVAL_ONLY accuracy run leaves it off and keeps
+# real verification. See the SGLANG_SIMULATE_ACC_* block.
+#
+# Required env vars:
+#   MODEL, TP, CONC, KV_OFFLOADING, TOTAL_CPU_DRAM_GB, RESULT_DIR
+#
+# KV_OFFLOADING=dram requires KV_OFFLOAD_BACKEND=hicache.
+
+source "$(dirname "$0")/../../benchmark_lib.sh"
+
+check_env_vars MODEL TP CONC KV_OFFLOADING TOTAL_CPU_DRAM_GB RESULT_DIR DURATION EP_SIZE
+
+SCHEDULER_RECV_INTERVAL=${SCHEDULER_RECV_INTERVAL:-10}
+
+if [[ -n "${SLURM_JOB_ID:-}" ]]; then
+    echo "JOB $SLURM_JOB_ID running on ${SLURMD_NODENAME:-unknown}"
+fi
+
+# `hf download` creates the target dir if missing and is itself idempotent.
+# When MODEL_PATH is unset (stand-alone runs), fall back to the HF_HUB_CACHE
+# Either way, MODEL_PATH is what the server is launched with.
+if [[ -n "${MODEL_PATH:-}" ]]; then
+    if [[ ! -d "$MODEL_PATH" || -z "$(ls -A "$MODEL_PATH" 2>/dev/null)" ]]; then
+        hf download "$MODEL" --local-dir "$MODEL_PATH"
+    fi
+else
+    hf download "$MODEL"
+    export MODEL_PATH="$MODEL"
+fi
+nvidia-smi
+
+# ---- Resolve traces and install deps ----------------------------------------
+# Keep the 256k-capped with-subagents corpus the H100 Qwen3.5 AgentX recipe
+# uses (470 traces, max in+out <= 256k). The unfiltered corpus has requests up
+# to ~1M proxy tokens that the server would reject; H200's extra HBM raises the
+# context ceiling but not past 256k for this model at TP8.
+export WEKA_LOADER_OVERRIDE=semianalysis_cc_traces_weka_with_subagents_256k
+
+resolve_trace_source
+install_agentic_deps
+
+# ---- Server config ----------------------------------------------------------
+SERVER_LOG="$RESULT_DIR/server.log"
+mkdir -p "$RESULT_DIR"
+
+CACHE_ARGS=()
+if require_agentic_kv_offload_backend hicache; then
+    # HiCache extends RadixAttention, so do not pass --disable-radix-cache.
+    # Hybrid GDN/Mamba allocates one KV and one Mamba host pool per rank.
+    REQUESTED_HICACHE_TOTAL_GB="${HICACHE_TOTAL_CPU_DRAM_GB:-$TOTAL_CPU_DRAM_GB}"
+    if [ "$REQUESTED_HICACHE_TOTAL_GB" -gt "$TOTAL_CPU_DRAM_GB" ]; then
+        echo "Error: requested HiCache pool ${REQUESTED_HICACHE_TOTAL_GB} GB exceeds configured capacity ${TOTAL_CPU_DRAM_GB} GB" >&2
+        exit 1
+    fi
+    TOTAL_CPU_DRAM_GB="$REQUESTED_HICACHE_TOTAL_GB"
+    HICACHE_HOST_POOL_COUNT="${HICACHE_HOST_POOL_COUNT:-2}"
+    HICACHE_WRITE_POLICY="${HICACHE_WRITE_POLICY:-write_through_selective}"
+    MAX_HICACHE_SIZE_GB=$((TOTAL_CPU_DRAM_GB / TP / HICACHE_HOST_POOL_COUNT))
+    HICACHE_SIZE_GB="${HICACHE_SIZE_GB:-$MAX_HICACHE_SIZE_GB}"
+    if [ "$HICACHE_SIZE_GB" -gt "$MAX_HICACHE_SIZE_GB" ]; then
+        echo "Error: HICACHE_SIZE_GB=$HICACHE_SIZE_GB exceeds configured per-pool limit $MAX_HICACHE_SIZE_GB" >&2
+        exit 1
+    fi
+    if [ "$HICACHE_SIZE_GB" -lt 1 ]; then
+        echo "Error: computed HICACHE_SIZE_GB=$HICACHE_SIZE_GB from TOTAL_CPU_DRAM_GB=$TOTAL_CPU_DRAM_GB, TP=$TP, HICACHE_HOST_POOL_COUNT=$HICACHE_HOST_POOL_COUNT" >&2
+        exit 1
+    fi
+    echo "HiCache CPU pool: ${HICACHE_SIZE_GB} GB per rank per host pool across TP=${TP}, host_pool_count=${HICACHE_HOST_POOL_COUNT}"
+    CACHE_ARGS=(
+        --page-size 64
+        --enable-hierarchical-cache
+        --hicache-size "$HICACHE_SIZE_GB"
+        --hicache-io-backend kernel
+        --hicache-mem-layout page_first
+        --hicache-write-policy "$HICACHE_WRITE_POLICY"
+    )
+fi
+
+echo "Starting SGLang server..."
+export PYTHONNOUSERSITE=1
+export SGLANG_ENABLE_SPEC_V2=1
+
+# 3 speculative tokens per step (num-steps 3, eagle-topk 1, 4 draft tokens),
+# the same MTP shape as the fixed-seq-len Qwen3.5 recipes.
+SPEC_ARGS=(
+    --speculative-algorithm NEXTN
+    --speculative-num-steps 3
+    --speculative-eagle-topk 1
+    --speculative-num-draft-tokens 4
+)
+
+# AgentX pins acceptance to the committed golden AL so submissions are compared
+# on system performance at a fixed acceptance target rather than on draft-head
+# quality (golden_al_distribution/README.md). 3.39 is the Qwen3.5 MTP curve at
+# num_speculative_tokens=3, thinking_on (golden_al_distribution/qwen3.5_mtp.yaml)
+# -- the same value the GB300 Qwen3.5 AgentX srt-slurm recipes pin.
+# SGLANG_SIMULATE_ACC_TOKEN_MODE landed in SGLang v0.5.16, which is why this
+# recipe pins that image rather than the non-MTP agentic sibling's v0.5.12.
+#
+# EVAL_ONLY leaves simulated acceptance off: it commits drafted tokens
+# regardless of the target logits, so generated text is wrong and the eval would
+# score ~0.
+if [ "${EVAL_ONLY:-false}" != "true" ]; then
+    # golden_al_distribution/qwen3.8next_mtp.yaml:
+    # qwen3.8-flash-next-fp8.thinking_on[3] = 2.32.
+    # --speculative-num-steps 3 with 4 draft tokens is 3 speculative tokens
+    # per verification step, i.e. the MTP=3 cell. AgentX replays run with
+    # thinking on, so the thinking_on row is the right one.
+    export SGLANG_SIMULATE_ACC_LEN=2.32
+    export SGLANG_SIMULATE_ACC_METHOD=match-expected
+    export SGLANG_SIMULATE_ACC_TOKEN_MODE=real-draft-token
+fi
+
+SGLANG_MULTI_TOKENIZER=/sgl-workspace/sglang/python/sglang/srt/managers/multi_tokenizer_mixin.py
+if ! sed -n '/elif isinstance(output, BatchStrOutput):/,/input_token_logprobs_val=_extract_field_by_index/p' "$SGLANG_MULTI_TOKENIZER" \
+    | grep -q 'cached_tokens_details=_extract_field_by_index'; then
+    sed -i '/elif isinstance(output, BatchStrOutput):/,/input_token_logprobs_val=_extract_field_by_index/ {
+        /cached_tokens=_extract_field_by_index(output, "cached_tokens", i),/a\
+            cached_tokens_details=_extract_field_by_index(\
+                output, "cached_tokens_details", i\
+            ),
+    }' "$SGLANG_MULTI_TOKENIZER"
+fi
+
+{ set +x; } 2>/dev/null
+# AgentX concurrency counts live session trees rather than individual HTTP
+# requests. Leave room for subagent fan-out, and do not spend HBM capturing
+# graphs above the batch sizes that stay useful for this long-context workload.
+# The Qwen3.5 H200 template left both flags commented out, so neither variable
+# existed; NEXTN silently caps --max-running-requests at 48 when it is unset.
+MAX_RUNNING_REQUESTS=$((2 * CONC))
+CUDA_GRAPH_MAX_BS="$CONC"
+if [ "$CUDA_GRAPH_MAX_BS" -gt 64 ]; then
+    CUDA_GRAPH_MAX_BS=64
+fi
+
+SGLANG_CMD=(
+    python3 -m sglang.launch_server
+    --model-path "$MODEL_PATH"
+    --served-model-name "$MODEL"
+    --host 0.0.0.0
+    --port "$PORT"
+    --trust-remote-code
+    # Verified flags from the SGLang cookbook playground for this model on
+    # H200 / FP8 / low latency / single node. NVFP4 is greyed out for Hopper,
+    # so FP8 is the whole verified surface here. TP4 with EP4, not TP8: the
+    # cookbook shards the 512-expert MoE across four ranks with expert
+    # parallelism rather than sharding attention eight ways.
+    --tp-size "$TP"
+    --ep-size "$EP_SIZE"
+    --dp-size 1
+    --mem-fraction-static 0.85
+    --chunked-prefill-size 8192
+    --linear-attn-prefill-backend flashinfer
+    --linear-attn-decode-backend flashinfer
+    # float32, not the cookbook's bfloat16. With NEXTN enabled the GDN linear
+    # attention backend routes verification through flashinfer's
+    # gated_delta_rule_mtp, which asserts initial_state.dtype == torch.float32
+    # and aborts CUDA graph capture on a bf16 SSM state:
+    #   AssertionError: initial_state must be float32, got torch.bfloat16
+    #   flashinfer/gdn_decode.py:761, via gdn_backend.py target_verify
+    # The cookbook command pairs bfloat16 with NEXTN, but this flashinfer build
+    # rejects that combination, and the state dtype is the half that can move.
+    --mamba-ssm-dtype float32
+    "${SPEC_ARGS[@]}"
+    --reasoning-parser auto
+    # NEXTN silently resets --max-running-requests to 48 when it is unset, so
+    # this must stay explicit and sized to the AgentX concurrency.
+    --max-running-requests "$MAX_RUNNING_REQUESTS"
+    --cuda-graph-max-bs "$CUDA_GRAPH_MAX_BS"
+    --stream-interval 50
+    --scheduler-recv-interval "$SCHEDULER_RECV_INTERVAL"
+    --tokenizer-worker-num 6
+    --tokenizer-path "$MODEL"
+    --enable-metrics
+    "${CACHE_ARGS[@]}"
+)
+printf '%q ' "${SGLANG_CMD[@]}" | tee "$RESULT_DIR/sglang_command.txt"
+printf '\n' | tee -a "$RESULT_DIR/sglang_command.txt"
+"${SGLANG_CMD[@]}" > "$SERVER_LOG" 2>&1 &
+SERVER_PID=$!
+echo "Server PID: $SERVER_PID"
+
+wait_for_server_ready --port "$PORT" --server-log "$SERVER_LOG" --server-pid "$SERVER_PID"
+
+if [ "${EVAL_ONLY}" = "true" ]; then
+    run_eval --port "$PORT"
+else
+    build_replay_cmd "$RESULT_DIR"
+    run_agentic_replay_and_write_outputs "$RESULT_DIR"
+fi
diff --git a/configs/nvidia-master.yaml b/configs/nvidia-master.yaml
index 4c1036915d..6a2f7e504d 100644
--- a/configs/nvidia-master.yaml
+++ b/configs/nvidia-master.yaml
@@ -7184,6 +7184,25 @@ qwen3.5-fp8-h200-sglang-agentic-mtp:
       - { tp: 8, ep: 8, spec-decoding: mtp, kv-offloading: none, conc-list: [4, 8, 12, 16] }
       - { tp: 8, ep: 8, spec-decoding: mtp, kv-offloading: dram, kv-offload-backend: { name: hicache }, conc-list: [4, 8, 12, 16] }
 
+
+# Qwen3.8-Flash-Next FP8 AgentX on H200 via SGLang with native NEXTN MTP.
+# Day-zero recipe. H200 is Hopper, so this arm is FP8: NVFP4 is greyed out for
+# this part in the SGLang cookbook. TP4 with EP4 per the cookbook's verified
+# low-latency single-node command, which shards the 512-expert MoE with expert
+# parallelism rather than sharding attention eight ways.
+qwen3.8next-fp8-h200-sglang-agentic-mtp:
+  image: lmsysorg/sglang:qwen38flashnext
+  model: Qwen/Qwen3.8-Flash-Next-FP8
+  model-prefix: qwen3.8next
+  runner: cluster:h200-dgxc
+  precision: fp8
+  framework: sglang
+  multinode: false
+  scenarios:
+    agentic-coding:
+    - dram-utilization: 0.8
+      search-space:
+      - { tp: 4, ep: 4, spec-decoding: mtp, kv-offloading: none, conc-list: [1, 4, 8, 12, 16] }
 # H200 AgentX MTP frontier with DRAM HiCache. This is intentionally an MTP-only
 # submission; the model's non-speculative AgentX arm is not included.
 qwen3.5-fp8-h200-sglang-agentic-hicache-mtp:
diff --git a/perf-changelog.yaml b/perf-changelog.yaml
index de9533314a..f25a76fb08 100644
--- a/perf-changelog.yaml
+++ b/perf-changelog.yaml
@@ -6490,3 +6490,15 @@
     - "Required lanes promote exporter startup timeouts, launch failures, and endpoint resolution failures to blocking validation failures, so a recipe cannot publish a result whose power collection never started."
     - "Route only enabled recipes through the immutable producer fork and preserve non-power launcher revisions."
   pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/2688
+
+- config-keys:
+    - qwen3.8next-fp8-h200-sglang-agentic-mtp
+  scenario-type:
+    - agentic-coding
+  description:
+    - "Add the day-zero Qwen3.8-Flash-Next FP8 AgentX recipe on H200 with SGLang native NEXTN MTP at TP8 and concurrency 1/4/8/12/16."
+    - "Use the FP8 checkpoint rather than NVFP4 because Hopper has no SM100 tensor cores, and keep the flashinfer attention backend for sm_90."
+    - "Correct the serve flags to the SGLang cookbook's verified low-latency single-node command for this model: TP4 with EP4 rather than TP8, memory fraction 0.85, chunked prefill 8192, the flashinfer linear-attention prefill and decode backends, bfloat16 Mamba SSM, and the NEXTN speculative algorithm."
+    - "Pin throughput runs to the committed golden thinking_on acceptance length of 2.32 at three speculative tokens; eval-only runs keep real target verification."
+    - "Use a float32 Mamba SSM state: flashinfer's gated_delta_rule_mtp verify kernel asserts float32 and aborts CUDA graph capture on the bfloat16 state the cookbook command specifies."
+  pr-link: https://github.com/SemiAnalysisAI/InferenceX/pull/2753