tau-bench
Agents chat with a simulated user and call retail or airline APIs under policy rules. A task passes if the final database matches the goal.
The repo marks its tasks as outdated and points to tau2-bench, now tau3-bench, which fixes airline and retail tasks.
- Made by
- Sierra
- Released
- June 2024
- Kind
- Customer service
- Level
- Everyday
- Scored
- Checked automatically
- Answers
- Agent task
- Tasks
- All public
- Strongest model tested
- o3 #83 on the capability index
- Last in a launch post
- September 2025, dropped for a newer version
- Last model added
- September 2025
In the authors’ words
Existing benchmarks do not test language agents on their interaction with human users or ability to follow domain-specific rules, both of which are vital for deploying them in real world applications. We propose τ-bench, a benchmark emulating dynamic conversations between a user (simulated by language models) and a language agent provided with domain-specific API tools and policy guidelines. We employ an efficient and faithful evaluation process that compares the database state at the end of a conversation with the annotated goal state. We also propose a new metric (pass^k) to evaluate the reliability of agent behavior over multiple trials. Our experiments show that even state-of-the-art function calling agents (like gpt-4o) succeed on <50% of the tasks, and are quite inconsistent (pass^8 <25% in retail). Our findings point to the need for methods that can improve the ability of agents to act consistently and follow rules reliably.
Claude Opus 4 leads with 70.5% among models released by September 2025
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.
The newest model with a score here came out in September 2025, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- Claude Fable 5.2
-
Gemini 4 Carbon
- GPT-6 Astra
- Claude Opus 5.5
- and 16 more
- 70.5 Claude Opus 4
- 70.3 Claude Sonnet 4
- 70.1 GLM-4.5
- 69.8 Claude 3.7 Sonnet
- 69.2 Claude Opus 4.1
- 68.8
Qwen3-Coder-480B-A35B
- 67.8 gpt-oss-120b
- 63.9 o1
- 62.8
MiniMax-M1-80k
- 61.2 o3
- 59.8
Command A Reasoning
- 59.3
Qwen3-Next-80B-A3B
- 58.7
DeepSeek-R1
- 58.2
seed-oss-36b-instruct
- 57.6 Claude 3.5 Sonnet (October 2024)
- 57.4 o4-mini
- 57.1
EXAONE 4.0 32B
- 56.9
Qwen3-235B-A22B-Thinking
- 54.8 gpt-oss-20b
- 54.7
Hunyuan-A13B-Instruct
- 51.7
Cohere Command A
- 45.9 GPT-4.1 mini
- 18.3 GPT-4.1 nano
- 1 Claude Opus 4 70.5%
- 2 Claude Sonnet 4 70.3%
- 3 GLM-4.5 70.1%
- 4 Claude 3.7 Sonnet 69.8%
- 5 Claude Opus 4.1 69.2%
- 6
Qwen3-Coder-480B-A35B 68.8%
- 7 gpt-oss-120b 67.8%
- 8 o1 63.9%
- 9
MiniMax-M1-80k 62.8%
- 10 o3 61.2%
- 11
Command A Reasoning 59.8%
- 12
Qwen3-Next-80B-A3B 59.3%
- 13
DeepSeek-R1 May 2025 58.7%
- 14
seed-oss-36b-instruct 58.2%
- 15 Claude 3.5 Sonnet (October 2024) 57.6%
- 16 o4-mini 57.4%
- 17
EXAONE 4.0 32B 57.1%
- 18
Qwen3-235B-A22B-Thinking Jul 2025 56.9%
- 19 gpt-oss-20b 54.8%
- 20
Hunyuan-A13B-Instruct 54.7%
- 21
Cohere Command A 51.7%
- 22 GPT-4.1 mini 45.9%
- 23 GPT-4.1 nano 18.3%
Source: Labs’ model cards
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Opus 4 | 70.5% | May 2025 | Lab model card | |
| 2 | Claude Sonnet 4 | 70.3% | May 2025 | Lab model card | |
| 3 | GLM-4.5 | 70.1% | Aug 2025 | Lab model card | |
| 4 | Claude 3.7 Sonnet | 69.8% | Feb 2025 | Lab model card | |
| 5 | Claude Opus 4.1 | 69.2% | Aug 2025 | Lab model card | |
| 6 | | 68.8% | Jul 2025 | Lab model card | |
| 7 | gpt-oss-120b | 67.8% | Aug 2025 | Lab model card | |
| 8 | o1 | 63.9% | Dec 2024 | Lab model card | |
| 9 | | 62.8% | Jun 2025 | Lab model card | |
| 10 | o3 | 61.2% | Apr 2025 | Lab model card | |
| 11 | | 59.8% | Aug 2025 | Lab model card | |
| 12 | | 59.3% | Sep 2025 | Lab model card | |
| 13 | | 58.7% | May 2025 | Lab model card | |
| 14 | | 58.2% | Aug 2025 | Lab model card | |
| 15 | Claude 3.5 Sonnet (October 2024) | 57.6% | Oct 2024 | Lab model card | |
| 16 | o4-mini | 57.4% | Apr 2025 | Lab model card | |
| 17 | | 57.1% | Jul 2025 | Lab model card | |
| 18 | | 56.9% | Jul 2025 | Lab model card | |
| 19 | gpt-oss-20b | 54.8% | Aug 2025 | Lab model card | |
| 20 | | 54.7% | Jun 2025 | Lab model card | |
| 21 | | 51.7% | Apr 2025 | Lab model card | |
| 22 | GPT-4.1 mini | 45.9% | Apr 2025 | Lab model card | |
| 23 | GPT-4.1 nano | 18.3% | Apr 2025 | Lab model card |
4 models have held number one in labs’ own numbers since its release in June 2024
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Labs’ model cards
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Labs’ model cards
Labs moved on to tau2-bench
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 |
|---|---|---|---|
| Sep 11, 2025 | 59.3 | Mean of TAU1-Retail 69.6 / TAU1-Airline 49.0 | |
| Aug 21, 2025 | 59.8 | tau-bench, average of retail and airline pass^1 over 10 runs | |
| Aug 20, 2025 | 58.2 | Mean of TAU1-Retail 70.4 / TAU1-Airline 46 | |
| Aug 5, 2025 | Claude Opus 4.1 | 69.2 | Mean of Agentic tool use TAU-bench Retail / Agentic tool use TAU-bench Airline |
| Jul 28, 2025 | GLM-4.5 | 70 | Mean of TAU-bench-Retail / TAU-bench-Airline |
| Jul 25, 2025 | 56.9 | Mean of TAU1-Retail / TAU1-Airline | |
| Jul 22, 2025 | 68.8 | Mean of TAU-Bench Retail 77.5 / TAU-Bench Airline 60.0 | |
| Jul 15, 2025 | 57.1 | Mean of Tau-Bench Airline 51.5 / Retail 62.8 (reasoning) | |
| Jun 27, 2025 | 54.7 | τ-Bench | |
| Jun 16, 2025 | 62.8 | Mean of TAU-bench (airline) / TAU-bench (retail) | |
| May 28, 2025 | 58.7 | Mean of Tau-Bench (Pass@1) Airline / Tau-Bench (Pass@1) Retail | |
| May 22, 2025 | Claude Sonnet 4 | 70.3 | Mean of TAU-bench Retail 80.5 / Airline 60.0 |
| May 22, 2025 | Claude Opus 4 | 70.5 | Mean of Agentic tool use TAU-bench Retail / Agentic tool use TAU-bench Airline |
| Apr 16, 2025 | o4-mini | 57.4 | Mean of TAU-bench Airline 49.2 / Retail 65.6 (o4-mini-high) |
| Apr 16, 2025 | o3 | 61.2 | Mean of Tau-bench Function Calling (Airline), o3-high / Tau-bench Function Calling (Retail), o3-high |
| Apr 14, 2025 | GPT-4.1 nano | 18.3 | Mean of Taubench airline 14.0 / retail 22.6 |
| Apr 14, 2025 | GPT-4.1 mini | 45.9 | Mean of Taubench airline 36.0 / retail 55.8 |
| Mar 13, 2025 | Taubench Retail and Airline (chart only) | ||
| Feb 24, 2025 | Claude 3.7 Sonnet | 69.8 | Mean of Agentic tool use TAU-bench Retail / Agentic tool use TAU-bench Airline |
| Dec 17, 2024 | o1 | 63.9 | Mean of TAU-bench (retail) / TAU-bench (airline) |
| Oct 22, 2024 | Claude 3.5 Sonnet (October 2024) | 57.6 | Mean of TAU-bench Retail (pass^1) / TAU-bench Airline (pass^1) |
10 system cards report it, from 7 labs
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 |
|---|---|---|---|---|
| Aug 8, 2025 | GLM-4.5 technical report | 70.1 | TAU-Bench, overall stated in the Introduction. Table 3 gives TAU-Retail 79.7 and TAU-Airline 60.4 | Capabilities |
| Aug 8, 2025 | GLM-4.5-Air technical report | TAU-Retail 77.9 and TAU-Airline 60.8, no overall score (Table 3) | Capabilities | |
| Aug 5, 2025 | gpt-oss-20b model card | 54.8 | Tau-Bench Retail, high reasoning (Tau-Bench Airline 38.0) (Table 3, Figure 2) | Capabilities |
| Aug 5, 2025 | gpt-oss-120b model card | 67.8 | Tau-Bench Retail, high reasoning (Tau-Bench Airline 49.2) (Table 3, Figure 2) | Capabilities |
| Jul 15, 2025 | | TAU-Bench Airline 51.5 and Retail 62.8, no overall, GPT-4.1 user (Table 3, Reasoning). Non-reasoning Airline 25.5, Retail 55.9 (Table 4) | Capabilities | |
| Jun 26, 2025 | | 54.7 | τ-Bench, slow-thinking (Table 3). Fast-thinking 42.6 (Table 4) | Capabilities |
| Jun 16, 2025 | | 62.8 | TAU-bench, printed bar label (Figure 1). Table 2: airline 62.0, retail 63.5 | Capabilities |
| Apr 1, 2025 | | 51.7 | Taubench (Table 1). Table 6: Retail pass@1 60.0, Airline pass@1 45.3, over 10 runs | Capabilities |
| Oct 22, 2024 | Claude 3.5 Sonnet (October 2024) model card | TAU-bench pass^1, no overall: Retail 69.2% and Airline 46.0% (Table 3) | Capabilities | |
| Oct 22, 2024 | Claude 3.5 Haiku model card | TAU-bench pass^1, no overall: Retail 51.0% and Airline 22.8% (Table 3) | Capabilities |
3 logged changes that move scores
Changes by the maintainers, so a score from before a change may not compare with one from after it. Newest first, each with the maintainers' own source. The list may be incomplete. What we log.
- Grader changed December 10th, 2024
The Sierra maintainers required both the final database state and requested outputs to be correct for full reward. The earlier grader could accept correct-looking text despite an incorrect database state. Source
- Questions corrected December 10th, 2024
The Sierra maintainers clarified retail test instructions to reduce simulated-user errors. Evaluations before and after this change present different guidance to the user simulator. Source
- Questions corrected July 10th, 2024
The Sierra maintainers corrected retail reference actions and clarified ambiguous user instructions. Earlier revisions can require different actions or mislead the simulated user, affecting task success. Source
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
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