Benchmark Almanac

tau3-bench

Mercury 2.5 96% leads since Sep 2026 In use

Agents use tools and follow policies while talking with simulated users in airline, retail, telecom, and banking domains. Scoring is task success rate.

Release 1.0.1 in July 2026 fixed banking grading, so earlier banking scores do not compare, and τ-bench 2.0 followed in October 2026.

In the authors’ words

Conversational agents are increasingly deployed in knowledge-intensive settings, where correct behavior depends on retrieving and applying domain-specific knowledge from large, proprietary, and unstructured corpora during live interactions with users. Yet most existing benchmarks evaluate retrieval or tool use independently of each other, creating a gap in realistic, fully agentic evaluation over unstructured data in long-horizon interactions. We introduce τ-Knowledge, an extension of τ-Bench for evaluating agents in environments where success depends on coordinating external, natural-language knowledge with tool outputs to produce verifiable, policy-compliant state changes. Our new domain, τ-Banking, models realistic fintech customer support workflows in which agents must navigate roughly 700 interconnected knowledge documents while executing tool-mediated account updates. Across embedding-based retrieval and terminal-based search, even frontier models with high reasoning budgets achieve only ~25.5% pass^1, with reliability degrading sharply over repeated trials. Agents struggle to retrieve the correct documents from densely interlinked knowledge bases and to reason accurately over complex internal policies. Overall, τ-Knowledge provides a realistic testbed for developing agents that integrate unstructured knowledge in human-facing deployments.

Abstract of τ-Knowledge: Evaluating Conversational Agents over Unstructured Knowledge (arXiv:2603.04370, CC0)
Made by Sierra Released Mar 2026 Customer service All tasks public Last in a launch post Oct 2026 Last model added Oct 2026 Scores refreshed 2 Nov 2026
Level
Everyday Most adults, without training
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
12
Models scored in lab cards
12
Launch posts list it, from 11 labs
1
System card reports it, from 1 lab

Mercury 2.5 leads with 96%

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

  1. 1 Mercury 2.5 96%
  2. 2 Nemotron 3 Ultra 86.9%
  3. 3 MiMo-V2.5-Pro 72.9%
  4. 4 Qwen 3.6 Plus 70.7%
  5. 5 GLM-5.1 70.6%
  6. 6 LFM3-1.7B 68%
  7. 7 ERNIE 5.1 67.9%
  8. 8 Qwen 3.6 35B-A3B 67.2%
  9. 9 Mistral Medium 3.5 63.2%
  10. 10 Granite 4.2 30B 62%
  11. 11 Spark-X2.6-4B 34.7%
  12. 12 Kimi K3 33.4%
#ModelScoreSettingDateSource
1 Mercury 2.5 96% Sep 2026 Model card
2 Nemotron 3 Ultra 86.9% Jun 2026 Model card
3 MiMo-V2.5-Pro 72.9% Apr 2026 Model card
4 Qwen 3.6 Plus 70.7% Apr 2026 Model card
5 GLM-5.1 70.6% Apr 2026 Model card
6 LFM3-1.7B 68% Oct 2026 Model card
7 ERNIE 5.1 67.9% May 2026 Model card
8 Qwen 3.6 35B-A3B 67.2% Apr 2026 Model card
9 Mistral Medium 3.5 63.2% May 2026 Model card
10 Granite 4.2 30B 62% Aug 2026 Model card
11 Spark-X2.6-4B 34.7% Oct 2026 Model card
12 Kimi K3 33.4% Jul 2026 Model card

The benchmark's own leaderboard has 7 models. We plot every source in the charts below.

Number one over time

Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard and what labs claim in their cards.

Qwen Xiaomi Corp NVIDIA Inception Labs
Own leaderboard Passed 85% in Mar 2026, by Qwen3.5 397B-A17B
Lab claims Passed 85% in Jun 2026, by Nemotron 3 Ultra

The best score passed 85% in Nov 2025

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) Mercury 2.5 Qwen3.5 397B-A17B Gemini 3 Pro Claude Sonnet 4.5 0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) Mercury 2.5 Qwen3.5 397B-A17B

6 labs put it in a launch post in the last six months

Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.

Qwen
Z.ai
Xiaomi Corp
Baidu
Mistral AI
NVIDIA
Moonshot AI
IBM
Inception Labs
iFlytek
Liquid AI
DateLaunch postScoreAs the post writes it
27 Oct 2026 LFM3-1.7B 68 τ³-bench
22 Oct 2026 Spark-X2.6-4B 34.7 τ³-bench
8 Sep 2026 Mercury 2.5 96 Tau3Bench Telecom (telecom domain only)
25 Aug 2026 Granite 4.2 30B 62 τ³-bench (AVG)
16 Jul 2026 Kimi K3 33.4 τ³-Banking
4 Jun 2026 Nemotron 3 Ultra 86.9 Mean of TauBench V3 Airline 81.5 / Retail 86.4 / Telecom 92.9
22 May 2026 Mistral Medium 3.5 63.2 Mean of τ³ Telecom / τ³ Airline / τ³ Retail / τ³ Banking
9 May 2026 ERNIE 5.1 67.9 τ3-bench (avg@4)
27 Apr 2026 MiMo-V2.5-Pro 72.9 τ³-bench
15 Apr 2026 Qwen 3.6 35B-A3B 67.2 TAU3-Bench (gpt-5.2 user model)
7 Apr 2026 GLM-5.1 70.6 τ³-Bench
2 Apr 2026 Qwen 3.6 Plus 70.7 TAU3-Bench

One system card reports it

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
9 Jun 2026 Nemotron 3 Ultra technical report 70.9 TauBench V3 Average of Airline 81.5, Retail 86.4, Telecom 92.9, Banking 22.6 (Table 10) Capabilities

Versions

We switch the top row to each new version when it comes out. Open it for one row per version. An old version stays in play while people still test it, so whoever first takes it past 85% gets credit for closing it out.

Anthropic OpenAI Moonshot AI Qwen MiniMax Inception Labs
tau3-bench Passed 85% in Mar 2026, by Qwen3.5 397B-A17B
tau-bench Replaced by tau2-bench, Sep 2025
tau2-bench Passed 85% in Oct 2025, by MiniMax-M2
GPT-5.4 98.9%
tau3-bench Passed 85% in Mar 2026, by Qwen3.5 397B-A17B

More in Tool use

All 125 in Tool use
  • AutomationBench In use Agent completes end-to-end business workflows inside a simulated company exposing dozens of REST APIs. Graded on resulting state. Gemini 4 Carbon 53.9%
  • MCP Atlas In use Multi-step workflows over real MCP servers. Scores tool-use competency on realistic tasks. Muse Spark 1.1 88.1%
  • BFCL V4 In use Models call functions and tools, including multi-turn agentic tasks with web search and memory. Checked against expected calls and outcomes. Qwen3.7-Max 75%
  • τ³-bench Banking In use Agents act as banking customer-service reps over many turns with a simulated user, following policy. Pass^1 on the final database state. Qwen 3.8 Max 55.1%
  • Claw-Eval In use 300 human-verified agent tasks (service orchestration, multimodal, multi-turn dialogue) audited via traces and snapshots. Rubric scores with Pass^3 consistency. Claude Sonnet 4.6 81.4%
  • DeepSearchQA In use Questions that need multi-step search and synthesis. Final answers graded against references. Kimi K3 95%