tau-bench Airline
Agents help simulated airline customers through tools while following airline policies on the original tasks. The score is pass^1 as a percentage.
One track of tau-bench. The tau-bench record keeps lab scores that combine tracks. Authors mark these original tasks as outdated and point to later benchmarks with revised tasks.
- Made by
- Sierra
- Released
- June 2024
- Kind
- Customer service
- Level
- Everyday
- Scored
- Checked automatically
- Answers
- Agent task
- Tasks
- All public
- Strongest model tested
- Claude 3.5 Sonnet (October 2024) #149 on the capability index
- Last model added
- October 2024
- Scores refreshed
- November 12th, 2026
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 3.5 Sonnet (October 2024) leads with 46%
Best score per entry from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders.
- 1 Claude 3.5 Sonnet (October 2024) 46%
- 2 gpt-4o (snapshot unspecified) 42%
- 3 Claude 3.5 Sonnet 36%
- 4 gpt-4o-mini (snapshot unspecified) 22.5%
Source: Official tau-bench Airline leaderboard
| # | Entry | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude 3.5 Sonnet (October 2024) | 46% | tool-calling | Oct 2024 | Official leaderboard |
| 2 | gpt-4o (snapshot unspecified) | 42% | tool-calling | Official leaderboard | |
| 3 | Claude 3.5 Sonnet | 36% | tool-calling | Jun 2024 | Official leaderboard |
| 4 | gpt-4o-mini (snapshot unspecified) | 22.5% | tool-calling | Official leaderboard |
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Official tau-bench Airline leaderboard
No lab model card reports it yet
We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.
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%