tau3-bench
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.
- Made by
- Sierra
- Released
- March 2026
- Kind
- Customer service
- Level
- Everyday
- Scored
- Checked automatically
- Answers
- Agent task
- Tasks
- All public
- Strongest model tested
- Kimi K3 #24 on the capability index
- Last in a launch post
- October 2026
- Last model added
- October 2026
- Scores refreshed
- November 12th, 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.
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.
Qwen3.5 397B-A17B leads with 87.9% across all independent runs
Best score per model across the official leaderboard, Epoch AI’s own runs and any board Epoch AI copied. Each bar and row names its source.
Mercury 2.5 leads with 96%, claims included
Best score per model from every source, including labs’ own numbers and claims Epoch AI collected from reports and papers. Labs pick their own settings, so a claim can beat an independent run of the same model.
- 1 Mercury 2.5 96%
- 2
Nemotron 3 Ultra 86.9%
- 3 GPT-Live-1 86.2%
- 4 MiMo-V2.5-Pro 72.9%
- 5
Qwen 3.6 Plus 70.7%
- 6 GLM-5.1 70.6%
- 7 LFM3-1.7B 68%
- 8
ERNIE 5.1 67.9%
- 9
Qwen 3.6 35B-A3B 67.2%
- 10
Mistral Medium 3.5 63.2%
- 11 Granite 4.2 30B 62%
- 12
Spark-X2.6-4B 34.7%
- 13 Kimi K3 33.4%
- 14 Grok 4.5 32.6%
Source: Labs’ model cards
- 1
Qwen3.5 397B-A17B enabled 87.9%
- 2 Claude Opus 4.5 high 85.3%
- 3 GPT-5.2 high 84.8%
- 4
Gemini 3 Flash high 83.5%
- 5
Gemini 3 Pro high 82.5%
- 6 GLM-5 enabled 81%
- 7 Claude Sonnet 4.5 enabled 76.4%
Source: Official tau3-bench leaderboard
- 96.0 Mercury 2.5
- 87.9
Qwen3.5 397B-A17B
- 86.9
Nemotron 3 Ultra
- 86.2 GPT-Live-1
- 85.3 Claude Opus 4.5
- 84.8 GPT-5.2
- 83.5
Gemini 3 Flash
- 82.5
Gemini 3 Pro
- 81.0 GLM-5
- 76.4 Claude Sonnet 4.5
- 72.9 MiMo-V2.5-Pro
- 70.7
Qwen 3.6 Plus
- 70.6 GLM-5.1
- 68.0 LFM3-1.7B
- 67.9
ERNIE 5.1
- 67.2
Qwen 3.6 35B-A3B
- 63.2
Mistral Medium 3.5
- 62.0 Granite 4.2 30B
- 34.7
Spark-X2.6-4B
- 33.4 Kimi K3
- 32.6 Grok 4.5
- 1 Mercury 2.5 96%
- 2
Qwen3.5 397B-A17B enabled 87.9%
- 3
Nemotron 3 Ultra 86.9%
- 4 GPT-Live-1 86.2%
- 5 Claude Opus 4.5 high 85.3%
- 6 GPT-5.2 high 84.8%
- 7
Gemini 3 Flash high 83.5%
- 8
Gemini 3 Pro high 82.5%
- 9 GLM-5 enabled 81%
- 10 Claude Sonnet 4.5 enabled 76.4%
- 11 MiMo-V2.5-Pro 72.9%
- 12
Qwen 3.6 Plus 70.7%
- 13 GLM-5.1 70.6%
- 14 LFM3-1.7B 68%
- 15
ERNIE 5.1 67.9%
- 16
Qwen 3.6 35B-A3B 67.2%
- 17
Mistral Medium 3.5 63.2%
- 18 Granite 4.2 30B 62%
- 19
Spark-X2.6-4B 34.7%
- 20 Kimi K3 33.4%
- 21 Grok 4.5 32.6%
Sources: Labs’ model cards and official tau3-bench leaderboard
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Mercury 2.5 | 96% | Sep 2026 | Lab model card | |
| 2 | | 86.9% | Jun 2026 | Lab model card | |
| 3 | GPT-Live-1 | 86.2% | Jul 2026 | Lab model card | |
| 4 | MiMo-V2.5-Pro | 72.9% | Apr 2026 | Lab model card | |
| 5 | | 70.7% | Apr 2026 | Lab model card | |
| 6 | GLM-5.1 | 70.6% | Apr 2026 | Lab model card | |
| 7 | LFM3-1.7B | 68% | Oct 2026 | Lab model card | |
| 8 | | 67.9% | May 2026 | Lab model card | |
| 9 | | 67.2% | Apr 2026 | Lab model card | |
| 10 | | 63.2% | May 2026 | Lab model card | |
| 11 | Granite 4.2 30B | 62% | Aug 2026 | Lab model card | |
| 12 | | 34.7% | Oct 2026 | Lab model card | |
| 13 | Kimi K3 | 33.4% | Jul 2026 | Lab model card | |
| 14 | Grok 4.5 | 32.6% | Jul 2026 | Lab model card |
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | | 87.9% | enabled | Feb 2026 | Official leaderboard |
| 2 | Claude Opus 4.5 | 85.3% | high | Nov 2025 | Official leaderboard |
| 3 | GPT-5.2 | 84.8% | high | Dec 2025 | Official leaderboard |
| 4 | | 83.5% | high | Dec 2025 | Official leaderboard |
| 5 | | 82.5% | high | Nov 2025 | Official leaderboard |
| 6 | GLM-5 | 81% | enabled | Feb 2026 | Official leaderboard |
| 7 | Claude Sonnet 4.5 | 76.4% | enabled | Sep 2025 | Official leaderboard |
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Mercury 2.5 | 96% | Sep 2026 | Lab model card | |
| 2 | | 87.9% | enabled | Feb 2026 | Official leaderboard |
| 3 | | 86.9% | Jun 2026 | Lab model card | |
| 4 | GPT-Live-1 | 86.2% | Jul 2026 | Lab model card | |
| 5 | Claude Opus 4.5 | 85.3% | high | Nov 2025 | Official leaderboard |
| 6 | GPT-5.2 | 84.8% | high | Dec 2025 | Official leaderboard |
| 7 | | 83.5% | high | Dec 2025 | Official leaderboard |
| 8 | | 82.5% | high | Nov 2025 | Official leaderboard |
| 9 | GLM-5 | 81% | enabled | Feb 2026 | Official leaderboard |
| 10 | Claude Sonnet 4.5 | 76.4% | enabled | Sep 2025 | Official leaderboard |
| 11 | MiMo-V2.5-Pro | 72.9% | Apr 2026 | Lab model card | |
| 12 | | 70.7% | Apr 2026 | Lab model card | |
| 13 | GLM-5.1 | 70.6% | Apr 2026 | Lab model card | |
| 14 | LFM3-1.7B | 68% | Oct 2026 | Lab model card | |
| 15 | | 67.9% | May 2026 | Lab model card | |
| 16 | | 67.2% | Apr 2026 | Lab model card | |
| 17 | | 63.2% | May 2026 | Lab model card | |
| 18 | Granite 4.2 30B | 62% | Aug 2026 | Lab model card | |
| 19 | | 34.7% | Oct 2026 | Lab model card | |
| 20 | Kimi K3 | 33.4% | Jul 2026 | Lab model card | |
| 21 | Grok 4.5 | 32.6% | Jul 2026 | Lab model card |
The benchmark's own leaderboard has 7 models. Switch the scores above to rank them together.
4 models have held number one in labs’ own numbers since its release in March 2026 Number one over time 2 models have held number one with claims included since its release in March 2026
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.
Sources: Official tau3-bench leaderboard and labs’ model cards
Claude Opus 4.5 on the official leaderboard passed 85% in November 2025
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Sources: Official tau3-bench leaderboard and labs’ model cards
8 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.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| Oct 27, 2026 | LFM3-1.7B | 68 | τ³-bench |
| Oct 22, 2026 | 34.7 | τ³-bench | |
| Sep 8, 2026 | Mercury 2.5 | 96 | Tau3Bench Telecom (telecom domain only) |
| Aug 25, 2026 | Granite 4.2 30B | 62 | τ³-bench (AVG) |
| Jul 16, 2026 | Kimi K3 | 33.4 | τ³-Banking |
| Jul 16, 2026 | Grok 4.5 | 32.6 | τ³-bench, banking, 32.6% |
| Jul 8, 2026 | GPT-Live-1 | 86.2 | Tau3 (Voice) Intelligence, Pass@1, GPT-Live-1 paired with GPT-6 Astra at medium reasoning effort (asterisked in the chart) |
| Jun 4, 2026 | 86.9 | Mean of TauBench V3 Airline 81.5 / Retail 86.4 / Telecom 92.9 | |
| May 22, 2026 | 63.2 | Mean of τ³ Telecom / τ³ Airline / τ³ Retail / τ³ Banking | |
| May 9, 2026 | 67.9 | τ3-bench (avg@4) | |
| Apr 27, 2026 | MiMo-V2.5-Pro | 72.9 | τ³-bench |
| Apr 15, 2026 | 67.2 | TAU3-Bench (gpt-5.2 user model) | |
| Apr 7, 2026 | GLM-5.1 | 70.6 | τ³-Bench |
| Apr 2, 2026 | 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.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| Jun 9, 2026 | | 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.
Sources: Official leaderboards and labs’ model cards
More 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.
Gemini 4 Argon 90.7%
- 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%
- Toolathlon-Verified In use 108 long-horizon tasks across 32 apps through about 600 MCP tools. Execution-based checkers inspect final environment state. GLM-5.3-Flash 78.4%
- DeepSearchQA In use Questions that need multi-step search and synthesis. Final answers graded against references. Kimi K3 95%