APEX-Accounting
Agents run month-end close tasks across 10 frozen business worlds with the apps an accountant uses. 100 tasks are graded against 1,475 rubric criteria.
Ten worlds are held out and an eleventh is open source. Mercor reports mean score and Pass@1.
- Made by
- Mercor with Ramp
- Released
- July 2026
- Kind
- Simulated companies
- Level
- Expert
- Scored
- Graded by a model
- Answers
- Agent task
- Tasks
- Public, plus a private test set
- Strongest model tested
- Claude Fable 5.2 #1 on the capability index
- Last in a launch post
- November 2026
- Last model added
- November 2026
- Scores refreshed
- November 13th, 2026
In the authors’ words
We introduce APEX-Accounting, a benchmark built by Mercor in partnership with Ramp, to assess whether frontier models can do the real work of accountants. Tasks include reconciling accounts, accruing expenses, posting transactions, and producing reports. The private eval set comprises 160 tasks, split across 10 worlds. Each world contains an accounting system, as well as spreadsheets, PDFs, and other files. Every task was authored and solved by experts in accounting and bookkeeping, who also wrote grading rubrics. Across nine frontier models, Claude-Fable-5 (Max) leads with 56.4% Mean Criteria@3, ahead of Muse-Spark-1.1 (xHigh) at 52.6%. No model scores more than 2.6% Pass^8 (GPT-5.6-Sol (Max+Pro)) and the highest Pass@8 is 21.5% (Muse-Spark-1.1 (xHigh)). We experiment with increasing the token budget from $1 to $50 and observe an instance of Simpson's paradox: scores increase as the token budget increases but within a given budget-constrained harness, scores are lower on tasks where the model spends more tokens. As APEX-Accounting is a closed benchmark, leaderboard evals can be run for any frontier model on request.
Gemini 4 Argon leads with 71.5%
Best score per entry from the benchmark's own leaderboard, read on November 13th, 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.
- 71.5
Gemini 4 Argon
- 70.7
Gemini 4 Carbon
- 70.4 Claude Fable 5.2
- 67.6
Gemini 4 Hydrogen
- 67.1
Muse Wonder
- 66.7 Claude Fable 5.1
- 65.5 Claude Opus 5.5
- 64.9
Muse Spark 1.3
- 64.7 GPT-6 Astra
- 64.5 Claude Sonnet 5.5
- 64.3 Claude Opus 5
- 64.3 GPT-6.1 Sol
- 63.7 GPT-6.1 Terra
- 62.4 Kimi K3.1 Pro
- 62.2 GPT-5.6 Sol
- 62.2 Claude Haiku 5.5
- 62.0
Inkling 2 Small
- 61.0 Claude Fable 5
- 60.3 Grok 4.6
- 60.0
MiniMax-M3.1-Flash
- 59.8 GPT-5.6 Terra
- 59.7 GPT-6 Sol
- 59.5 GLM-5.3
- 59.3
DeepSeek V4.1 Flash 1017
- 58.8
Gemini 3.8 Flash
- 58.0
Muse Spark Open
- 57.4 Grok 4.5
- 57.2
Qwen 3.8 Max
- 57.2
Gemini 3.7 Flash
- 56.7 Kimi K3
- 56.5 Claude Opus 4.7
- 56.5
Mistral Large 4
- 56.3 GPT-5.5
- 55.7 Claude Sonnet 5
- 55.3 Grok 4.7
- 54.3 GPT-5.6 Luna
- 53.9 GPT-6 Luna
- 53.7 GLM-5.3-Flash
- 53.4
DeepSeek V4 Pro 0813
- 53.3
DeepSeek-V4-Flash
- 52.5
Gemini 3.6 Flash
- 50.8 Mercury 3
- 50.1
DeepSeek V4.1 Flash
- 41.8
MiniMax-M3
- 38.1
Nemotron 3.5 Super VL
- 35.7 Nemotron 3.5 Bolt
- 31.4
Gemini 3.5 Flash
- 31.2
Inkling
- 29.4
Nemotron 3 Ultra
- 5.20
Gemini 3.5 Flash-Lite
- 1
Gemini 4 Argon high 71.5%
- 2
Gemini 4 Carbon high 70.7%
- 3 Claude Fable 5.2 max 70.4%
- 4
Gemini 4 Hydrogen xhigh 67.6%
- 5
Muse Wonder max 67.1%
- 6 Claude Fable 5.1 max 66.7%
- 7 Claude Opus 5.5 max 65.5%
- 8
Muse Spark 1.3 max 64.9%
- 9 GPT-6 Astra max 64.7%
- 10 Claude Sonnet 5.5 max 64.5%
- 11 Claude Opus 5 max 64.3%
- 12 GPT-6.1 Sol max 64.3%
- 13 GPT-6.1 Terra max 63.7%
- 14 Kimi K3.1 Pro max 62.4%
- 15 GPT-5.6 Sol max 62.2%
- 16 Claude Haiku 5.5 max 62.2%
- 17
Inkling 2 Small 62%
- 18 Claude Fable 5 max 61%
- 19 Grok 4.6 xhigh 60.3%
- 20
MiniMax-M3.1-Flash max 60%
- 21 GPT-5.6 Terra max 59.8%
- 22 GPT-6 Sol max 59.7%
- 23 GLM-5.3 max 59.5%
- 24
DeepSeek V4.1 Flash 1017 max 59.3%
- 25
Gemini 3.8 Flash high 58.8%
- 26
Muse Spark Open xhigh 58%
- 27 Grok 4.5 high 57.4%
- 28
Qwen 3.8 Max xhigh 57.2%
- 29
Gemini 3.7 Flash high 57.2%
- 30 Kimi K3 max 56.7%
- 31 Claude Opus 4.7 max 56.5%
- 32
Mistral Large 4 high 56.5%
- 33 GPT-5.5 xhigh 56.3%
- 34 Claude Sonnet 5 max 55.7%
- 35 Grok 4.7 xhigh 55.3%
- 36 GPT-5.6 Luna max 54.3%
- 37 GPT-6 Luna max 53.9%
- 38 GLM-5.3-Flash max 53.7%
- 39
DeepSeek V4 Pro 0813 max 53.4%
- 40
DeepSeek-V4-Flash max 53.3%
- 41
Gemini 3.6 Flash high 52.5%
- 42 Mercury 3 high 50.8%
- 43
DeepSeek V4.1 Flash max 50.1%
- 44
MiniMax-M3 high 41.8%
- 45
Nemotron 3.5 Super VL high 38.1%
- 46 Nemotron 3.5 Bolt high 35.7%
- 47
Gemini 3.5 Flash high 31.4%
- 48
Inkling high 31.2%
- 49
Nemotron 3 Ultra high 29.4%
- 50
Gemini 3.5 Flash-Lite high 5.20%
Source: Official APEX-Accounting leaderboard
| # | Entry | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | | 71.5% | high, loop_agent | Sep 2026 | Official leaderboard |
| 2 | | 70.7% | high, loop_agent | Oct 2026 | Official leaderboard |
| 3 | Claude Fable 5.2 | 70.4% | max, loop_agent | Nov 2026 | Official leaderboard |
| 4 | | 67.6% | xhigh, loop_agent | Nov 2026 | Official leaderboard |
| 5 | | 67.1% | max, loop_agent | Oct 2026 | Official leaderboard |
| 6 | Claude Fable 5.1 | 66.7% | max, loop_agent | Sep 2026 | Official leaderboard |
| 7 | Claude Opus 5.5 | 65.5% | max, loop_agent | Sep 2026 | Official leaderboard |
| 8 | | 64.9% | max, loop_agent | Sep 2026 | Official leaderboard |
| 9 | GPT-6 Astra | 64.7% | max, loop_agent | Sep 2026 | Official leaderboard |
| 10 | Claude Sonnet 5.5 | 64.5% | max, loop_agent | Sep 2026 | Official leaderboard |
| 11 | Claude Opus 5 | 64.3% | max, loop_agent | Jul 2026 | Official leaderboard |
| 12 | GPT-6.1 Sol | 64.3% | max, loop_agent | Sep 2026 | Official leaderboard |
| 13 | GPT-6.1 Terra | 63.7% | max, loop_agent | Oct 2026 | Official leaderboard |
| 14 | Kimi K3.1 Pro | 62.4% | max, loop_agent | Oct 2026 | Official leaderboard |
| 15 | GPT-5.6 Sol | 62.2% | max, loop_agent | Jul 2026 | Official leaderboard |
| 16 | Claude Haiku 5.5 | 62.2% | max, loop_agent | Oct 2026 | Official leaderboard |
| 17 | | 62% | loop_agent | Nov 2026 | Official leaderboard |
| 18 | Claude Fable 5 | 61% | max, loop_agent | Jun 2026 | Official leaderboard |
| 19 | Grok 4.6 | 60.3% | xhigh, loop_agent | Aug 2026 | Official leaderboard |
| 20 | | 60% | max, loop_agent | Oct 2026 | Official leaderboard |
| 21 | GPT-5.6 Terra | 59.8% | max, loop_agent | Jul 2026 | Official leaderboard |
| 22 | GPT-6 Sol | 59.7% | max, loop_agent | Sep 2026 | Official leaderboard |
| 23 | GLM-5.3 | 59.5% | max, loop_agent | Aug 2026 | Official leaderboard |
| 24 | | 59.3% | max, loop_agent | Oct 2026 | Official leaderboard |
| 25 | | 58.8% | high, loop_agent | Sep 2026 | Official leaderboard |
| 26 | | 58% | xhigh, loop_agent | Oct 2026 | Official leaderboard |
| 27 | Grok 4.5 | 57.4% | high, loop_agent | Jul 2026 | Official leaderboard |
| 28 | | 57.2% | xhigh, loop_agent | Aug 2026 | Official leaderboard |
| 29 | | 57.2% | high, loop_agent | Aug 2026 | Official leaderboard |
| 30 | Kimi K3 | 56.7% | max, loop_agent | Jul 2026 | Official leaderboard |
| 31 | Claude Opus 4.7 | 56.5% | max, loop_agent | Apr 2026 | Official leaderboard |
| 32 | | 56.5% | high, loop_agent | Oct 2026 | Official leaderboard |
| 33 | GPT-5.5 | 56.3% | xhigh, loop_agent | Apr 2026 | Official leaderboard |
| 34 | Claude Sonnet 5 | 55.7% | max, loop_agent | Jun 2026 | Official leaderboard |
| 35 | Grok 4.7 | 55.3% | xhigh, loop_agent | Sep 2026 | Official leaderboard |
| 36 | GPT-5.6 Luna | 54.3% | max, loop_agent | Jul 2026 | Official leaderboard |
| 37 | GPT-6 Luna | 53.9% | max, loop_agent | Sep 2026 | Official leaderboard |
| 38 | GLM-5.3-Flash | 53.7% | max, loop_agent | Aug 2026 | Official leaderboard |
| 39 | | 53.4% | max, loop_agent | Aug 2026 | Official leaderboard |
| 40 | | 53.3% | max, loop_agent | Apr 2026 | Official leaderboard |
| 41 | | 52.5% | high, loop_agent | Jul 2026 | Official leaderboard |
| 42 | Mercury 3 | 50.8% | high, loop_agent | Oct 2026 | Official leaderboard |
| 43 | | 50.1% | max, loop_agent | Sep 2026 | Official leaderboard |
| 44 | | 41.8% | high, loop_agent | Jun 2026 | Official leaderboard |
| 45 | | 38.1% | high, loop_agent | Oct 2026 | Official leaderboard |
| 46 | Nemotron 3.5 Bolt | 35.7% | high, loop_agent | Official leaderboard | |
| 47 | | 31.4% | high, loop_agent | May 2026 | Official leaderboard |
| 48 | | 31.2% | high, loop_agent | Jul 2026 | Official leaderboard |
| 49 | | 29.4% | high, loop_agent | Jun 2026 | Official leaderboard |
| 50 | | 5.20% | high, loop_agent | Jul 2026 | Official leaderboard |
Labs report scores for 1 model in their cards. We plot every source in the charts below.
Cost vs. Performance
Mercor costPerRun values are preserved without assuming a per-task denominator. The line joins the runs that no other run beats on both measures. We redrew this chart from the numbers on the official leaderboard.
| Model | Setting | Mean score | Source cost per run |
|---|---|---|---|
| | high, loop_agent | 71.5% | $2.04 |
| | max, loop_agent | 67.1% | $4.91 |
| Claude Fable 5.1 | max, loop_agent | 66.7% | $5.73 |
| Claude Opus 5.5 | max, loop_agent | 65.5% | $3.54 |
| | max, loop_agent | 64.9% | $2.39 |
| GPT-6 Astra | max, loop_agent | 64.7% | $3.07 |
| Claude Sonnet 5.5 | max, loop_agent | 64.5% | $2.09 |
| GPT-6.1 Sol | max, loop_agent | 64.3% | $0.63 |
| Claude Opus 5 | max, loop_agent | 64.3% | $3.29 |
| GPT-6.1 Terra | max, loop_agent | 63.7% | $0.46 |
| Kimi K3.1 Pro | max, loop_agent | 62.4% | $2.98 |
| Claude Haiku 5.5 | max, loop_agent | 62.2% | $0.15 |
| GPT-5.6 Sol | max, loop_agent | 62.2% | $3.04 |
| Claude Fable 5 | max, loop_agent | 61% | $7.14 |
| Grok 4.6 | xhigh, loop_agent | 60.3% | $2.08 |
| | max, loop_agent | 60% | $0.16 |
| GPT-5.6 Terra | max, loop_agent | 59.8% | $2.33 |
| GPT-6 Sol | max, loop_agent | 59.7% | $1.24 |
| GLM-5.3 | max, loop_agent | 59.5% | $1.98 |
| | max, loop_agent | 59.3% | $0.18 |
| | high, loop_agent | 58.8% | $0.79 |
| | xhigh, loop_agent | 58% | $1.1 |
| Grok 4.5 | high, loop_agent | 57.4% | $0.81 |
| | high, loop_agent | 57.2% | $0.75 |
| | xhigh, loop_agent | 57.2% | $1.77 |
| Kimi K3 | max, loop_agent | 56.7% | $1.66 |
| | high, loop_agent | 56.5% | $0.73 |
| Claude Opus 4.7 | max, loop_agent | 56.5% | $4.1 |
| GPT-5.5 | xhigh, loop_agent | 56.3% | $2.81 |
| Claude Sonnet 5 | max, loop_agent | 55.7% | $2.25 |
| Grok 4.7 | xhigh, loop_agent | 55.3% | $2.63 |
| GPT-5.6 Luna | max, loop_agent | 54.3% | $0.23 |
| GPT-6 Luna | max, loop_agent | 53.9% | $0.14 |
| GLM-5.3-Flash | max, loop_agent | 53.7% | $0.24 |
| | max, loop_agent | 53.4% | $1.04 |
| | max, loop_agent | 53.3% | $0.16 |
| | high, loop_agent | 52.5% | $0.57 |
| Mercury 3 | high, loop_agent | 50.8% | $0.05 |
| | max, loop_agent | 50.1% | $0.29 |
| | high, loop_agent | 41.8% | $0.15 |
| | high, loop_agent | 38.1% | $0.14 |
| Nemotron 3.5 Bolt | high, loop_agent | 35.7% | $0.11 |
| | high, loop_agent | 31.4% | $3.56 |
| | high, loop_agent | 31.2% | $0.5 |
| | high, loop_agent | 29.4% | $0.24 |
| | high, loop_agent | 5.2% | $0.07 |
5 models have held number one on the official leaderboard since its release in July 2026
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Official APEX-Accounting leaderboard
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Sources: Official APEX-Accounting leaderboard and labs’ model cards
One lab 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 |
|---|---|---|---|
| Nov 5, 2026 | 14.5 | Apex-Accounting v1.1 pass@1 (mean score 62.0) |
One lab claim next to the leaderboard
Each score a lab reported for its own model, beside the same model's best score on the leaderboard. Gaps mostly come from different harnesses, effort levels and task subsets. Every benchmark.
| Model | Lab says | Board says | Gap |
|---|---|---|---|
| | 14.5% Apex-Accounting v1.1 pass@1 (mean score 62.0) | 62% Leaderboard, loop_agent | −48 pts |
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