NextSearch-1-XS

NextSearch-1-XS is the smallest NextSearch-1 web research agent: a post-trained model that decomposes a question, searches and fetches from the live web, reconciles conflicting evidence, and returns a concise answer or a structured research artifact. The family is built to work as the research component inside a larger system — called repeatedly by an orchestrator — where per-call accuracy, tail latency, and cost compound. XS is the price/latency point: a 9B dense model you can serve on one GPU.

Model Base Params
NextSearch-1-M Inkling-Small 276B-A12B MoE weights
NextSearch-1-S Qwen3.6-35B-A3B 35B-A3B MoE weights
NextSearch-1-XS (this repo) Qwen3.5-9B 9B dense weights

Technical report: nexttoken.co/research/nextsearch-1. Harness, evaluation suite, and audited benchmark golds: github.com/NextTokenAI/nextsearch.

Results

Live-web evaluation (August 2026), against small and cheap models. Benchmarks: SEAL-0 (fresh/conflicting evidence, n=97), FRAMES (multi-constraint retrieval, n=100), DeepSearchQA (comprehensive answer sets, n=100), WideSearch-sub (structured table sub-tasks, n=49). Best per column in bold.

SEAL-0 FRAMES DeepSearchQA WideSearch-sub mean $/ep mean turns
NextSearch-1-XS 0.289 0.790 0.588 0.703 $0.093 7.0
claude-haiku-4.5 0.258 0.720 0.670 0.864 $0.154 8.7
qwen3.5-9b (base) 0.206 0.700 0.599 0.610 $0.030 9.7
gemma-4-31b 0.155 0.670 0.565 0.667 $0.013 5.0
gemini-3.5-flash-lite 0.216 0.570 0.535 0.640 $0.020 7.3
gpt-oss-20b 0.206 0.710 0.406 0.470 $0.012 10.5

The table above is the conservative arm (parallel search backend). With the recommended exa-auto backend XS's four-bench mean rises from 0.592 to 0.693 (0.412 / 0.860 / 0.771 / 0.728) — above every genuinely small model on every bench except haiku's WideSearch-sub, and edging the 550B nemotron-3-ultra anchor (0.682) at a fraction of the size.

All rows run under our harness (same tools, prompts, turn budgets, pinned task date) against audited golds with one shared judge — consistent within this table, not comparable to other papers' leaderboards. Protocol and reproduction: docs/evals.md; full analysis in the technical report.

Quick start

vllm serve NextTokenAI/NextSearch-1-XS \
  --enable-auto-tool-choice --tool-call-parser hermes --max-model-len 65536

Recommended sampling: temperature 0.7, max 16k tokens per turn, thinking on. The model expects a task date in its system prompt and two tools (search, fetch); the exact prompts and tool schemas it was tuned for ship in the harness:

pip install nextsearch && nextsearch-eval run --benches seal0 --models nextsearch-1-xs --n 10

Or plain transformers:

from transformers import AutoModelForCausalLM, AutoTokenizer
model = AutoModelForCausalLM.from_pretrained(
    "NextTokenAI/NextSearch-1-XS", torch_dtype="auto", device_map="auto")
tokenizer = AutoTokenizer.from_pretrained("NextTokenAI/NextSearch-1-XS")

Serving pitfalls that fail silently (tool-call parsing, context caps, thinking retention): docs/serving.md.

License

Released under the Apache License 2.0, as is the base model Qwen/Qwen3.5-9B.

Citation

@techreport{nextsearch1,
  title       = {NextSearch-1: Open models for wide and deep web research},
  author      = {Nitish Kulkarni and Alankar Jain},
  institution = {NextToken},
  year        = {2026},
  url         = {https://nexttoken.co/research/nextsearch-1}
}
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