API-Bank
Models make API calls in dialogues that need tools such as calendars and search. Scored on call accuracy.
Llama 3 reports zero-shot function calling accuracy.
In the authors’ words
Recent research has demonstrated that Large Language Models (LLMs) can enhance their capabilities by utilizing external tools. However, three pivotal questions remain unanswered: (1) How effective are current LLMs in utilizing tools? (2) How can we enhance LLMs' ability to utilize tools? (3) What obstacles need to be overcome to leverage tools? To address these questions, we introduce API-Bank, a groundbreaking benchmark, specifically designed for tool-augmented LLMs. For the first question, we develop a runnable evaluation system consisting of 73 API tools. We annotate 314 tool-use dialogues with 753 API calls to assess the existing LLMs' capabilities in planning, retrieving, and calling APIs. For the second question, we construct a comprehensive training set containing 1,888 tool-use dialogues from 2,138 APIs spanning 1,000 distinct domains. Using this dataset, we train Lynx, a tool-augmented LLM initialized from Alpaca. Experimental results demonstrate that GPT-3.5 exhibits improved tool utilization compared to GPT-3, while GPT-4 excels in planning. However, there is still significant potential for further improvement. Moreover, Lynx surpasses Alpaca's tool utilization performance by more than 26 pts and approaches the effectiveness of GPT-3.5. Through error analysis, we highlight the key challenges for future research in this field to answer the third question.
- 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
- Short answer A number, word or short string matched to a key.
Llama 3.1-405B leads with 92.3% among models released by Jul 2024
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 Jul 2024, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 1
Llama 3.1-405B 92.3%
- 2
Llama 3.1-70B 90%
- 3
Llama 3.1-8B 82.6%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | | 92.3% | Nov 2024 | Model card | |
| 2 | | 90% | Jul 2024 | Model card | |
| 3 | | 82.6% | Jul 2024 | Model card |
Number one over time
Lab claims count from the day the card came out, independent runs from the model’s release.
The best score passed 85% in Jul 2024
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Labs report it only in system cards
We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.
6 system cards report it, from 1 lab
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 |
|---|---|---|---|---|
| 23 Nov 2024 | | 82.6 | API-Bank, zero-shot function calling accuracy, post-trained (Table 22) | Capabilities |
| 23 Nov 2024 | | 90 | API-Bank, zero-shot function calling accuracy, post-trained (Table 22) | Capabilities |
| 23 Nov 2024 | | 92.3 | API-Bank, zero-shot function calling accuracy, post-trained (Table 22) | Capabilities |
| 23 Jul 2024 | | 82.6 | API-Bank, 0-shot, acc, instruction tuned (Instruction tuned models table) | Capabilities |
| 23 Jul 2024 | | 90 | API-Bank, 0-shot, acc, instruction tuned (Instruction tuned models table) | Capabilities |
| 23 Jul 2024 | | 92 | API-Bank, 0-shot, acc, instruction tuned (Instruction tuned models table) | Capabilities |
More in Tool use
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Gemini 4 Carbon 53.9%
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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%