Table 2. Leaderboard. Ranges are 95% bootstrap intervals over tasks; # ranks on success, pairs whose intervals overlap sharing a rank. Any column sorts.
Figure 2. How each scored trial ended. A guard is a pass-to-pass case; the table bins failures that kept every guard by the share of must-fix cases fixed. 21 tasks without a must-fix and guard split left out.
Where failures fall
Claude Sonnet 5.5Claude Code
Gemini 4 ArgonAntigravity CLI
Muse Spark 1.3Muse Code
Gemini 3.8 FlashTerminus 2
Failing trials
88
123
222
242
On tasks the pair never passes
3641%
5242%
10045%
16367%
On tasks the pair passes in another trial
5259%
7158%
12255%
7933%
Most failures are near misses
About half of Sonnet's, Muse's and Flash's failures broke nothing and fixed three quarters or more of the must-fix cases.
Inconsistency, not capability
Over half of Sonnet's, Argon's and Muse's failures are on tasks the pair passes in another trial. Two thirds of Flash's are on tasks it never passes.
1×2×5×10×Cost gap by factor, log scaleClaude Sonnet 5.5Claude Code1×Gemini 4 ArgonAntigravity CLIGemini 4 Argon, Trials per pass: 1.1××1.1Gemini 4 Argon, Steps per trial: 3.1××3.1Gemini 4 Argon, Tokens per step: 2.8××2.8Gemini 4 Argon, Price per token, after caching: 1.0××1.0Gemini 4 Argon, total: 9.2×9.2×Muse Spark 1.3Muse CodeMuse Spark 1.3, Trials per pass: 1.4××1.4Muse Spark 1.3, Steps per trial: 3.7××3.7Muse Spark 1.3, Tokens per step: 1.5××1.5Muse Spark 1.3, Price per token, after caching: 0.83××0.83Muse Spark 1.3, total: 6.5×6.5×Gemini 3.8 FlashTerminus 2Gemini 3.8 Flash, Trials per pass: 1.4××1.4Gemini 3.8 Flash, Steps per trial: 8.7××8.7Gemini 3.8 Flash, Tokens per step: 1.1××1.1Gemini 3.8 Flash, Price per token, after caching: 0.82××0.82Gemini 3.8 Flash, total: 12×12×
1×2×5×10×Cost gap by factor, log scaleClaude Sonnet 5.5Claude Code1×Gemini 4 ArgonAntigravity CLIGemini 4 Argon, Trials per pass: 1.1××1.1Gemini 4 Argon, Steps per trial: 3.1××3.1Gemini 4 Argon, Tokens per step: 2.8××2.8Gemini 4 Argon, Price per token, after caching: 1.0××1.0Gemini 4 Argon, total: 9.2×9.2×Muse Spark 1.3Muse CodeMuse Spark 1.3, Trials per pass: 1.4××1.4Muse Spark 1.3, Steps per trial: 3.7××3.7Muse Spark 1.3, Tokens per step: 1.5××1.5Muse Spark 1.3, Price per token, after caching: 0.83××0.83Muse Spark 1.3, total: 6.5×6.5×Gemini 3.8 FlashTerminus 2Gemini 3.8 Flash, Trials per pass: 1.4××1.4Gemini 3.8 Flash, Steps per trial: 8.7××8.7Gemini 3.8 Flash, Tokens per step: 1.1××1.1Gemini 3.8 Flash, Price per token, after caching: 0.82××0.82Gemini 3.8 Flash, total: 12×12×
Trials per passSteps per trialTokens per stepPrice per token, after cachingTotal, the product, in the pair’s hue
Figure 4. Cost gap to Claude Sonnet 5.5, by factor. Dollars per success = trials per pass × steps per trial × tokens per step × price per token after caching. Log scale.
After caching, price per token is flat. Steps and context set the cost.
Against Sonnet: Flash 11.7× per success (8.7× the steps), Argon 9.2× (3.1× the steps, 2.8× the context), Muse 6.5× (3.7× the steps). With 83% or more of input cached, a step costs what its context costs.
Claude Sonnet 5.5Claude Code0200k400k600k0%50%100%Claude Sonnet 5.5 at 0%: median 24k, middle half 23k to 24kClaude Sonnet 5.5 at 11%: median 37k, middle half 29k to 46kClaude Sonnet 5.5 at 22%: median 53k, middle half 42k to 68kClaude Sonnet 5.5 at 33%: median 63k, middle half 51k to 82kClaude Sonnet 5.5 at 44%: median 70k, middle half 57k to 93kClaude Sonnet 5.5 at 56%: median 77k, middle half 62k to 102kClaude Sonnet 5.5 at 67%: median 82k, middle half 65k to 109kClaude Sonnet 5.5 at 78%: median 86k, middle half 67k to 114kClaude Sonnet 5.5 at 89%: median 89k, middle half 71k to 119kClaude Sonnet 5.5 at 100%: median 92k, middle half 72k to 122kGemini 4 ArgonAntigravity CLI0200k400k600k0%50%100%Gemini 4 Argon at 0%: median 13k, middle half 12k to 13kGemini 4 Argon at 11%: median 89k, middle half 67k to 115kGemini 4 Argon at 22%: median 146k, middle half 114k to 184kGemini 4 Argon at 33%: median 194k, middle half 145k to 236kGemini 4 Argon at 44%: median 237k, middle half 183k to 292kGemini 4 Argon at 56%: median 284k, middle half 221k to 345kGemini 4 Argon at 67%: median 330k, middle half 256k to 405kGemini 4 Argon at 78%: median 363k, middle half 283k to 458kGemini 4 Argon at 89%: median 396k, middle half 310k to 498kGemini 4 Argon at 100%: median 420k, middle half 325k to 523kMuse Spark 1.3Muse Code0200k400k600k0%50%100%Muse Spark 1.3 at 0%: median 15k, middle half 15k to 15kMuse Spark 1.3 at 11%: median 62k, middle half 51k to 76kMuse Spark 1.3 at 22%: median 92k, middle half 77k to 109kMuse Spark 1.3 at 33%: median 110k, middle half 94k to 134kMuse Spark 1.3 at 44%: median 125k, middle half 106k to 151kMuse Spark 1.3 at 56%: median 137k, middle half 117k to 166kMuse Spark 1.3 at 67%: median 148k, middle half 125k to 180kMuse Spark 1.3 at 78%: median 158k, middle half 134k to 195kMuse Spark 1.3 at 89%: median 168k, middle half 141k to 208kMuse Spark 1.3 at 100%: median 176k, middle half 148k to 219kGemini 3.8 FlashTerminus 20200k400k600k0%50%100%Gemini 3.8 Flash at 0%: median 2k, middle half 1k to 2kGemini 3.8 Flash at 11%: median 28k, middle half 24k to 34kGemini 3.8 Flash at 22%: median 48k, middle half 40k to 56kGemini 3.8 Flash at 33%: median 68k, middle half 57k to 81kGemini 3.8 Flash at 44%: median 92k, middle half 78k to 110kGemini 3.8 Flash at 56%: median 118k, middle half 99k to 141kGemini 3.8 Flash at 67%: median 144k, middle half 123k to 173kGemini 3.8 Flash at 78%: median 168k, middle half 145k to 200kGemini 3.8 Flash at 89%: median 192k, middle half 164k to 228kGemini 3.8 Flash at 100%: median 209k, middle half 179k to 246k
Median25th to 75th percentilePrompt tokens per call against position in the trajectory, first turn to last
Figure 5. Context per step over a trajectory. Largest prompt sent so far; median, middle half shaded.
123 of Argon's 600 trials hit the 2-hour limit; 90 of those passed. The fix was in, and Argon kept re-checking with context near 400k tokens a call. Knowing when it is done is worth more to Argon than a better fix.
The tasks are built for scaling RL, built on TrueReward, our environment infrastructure, that includes high fidelity enterprise system runtimes. We present below the runtimes used in EnterpriseSWE.
Task
The task statement
→
Agent container
The service tree, its migrations and client code
The stack up locally, to build and run against
A shell through the harness under test
changed tree→
Grader container
Rebuild the changed services
Run copies; kill, freeze, cut, stall and shift the clock as the case says
Run the must-fix and must-not-break cases
→
Reward
1 if every case passes, else 0
Runtimes
PostgreSQL 17, seeded
Redis 8
Kafka
DynamoDB Local, S3, SQS, SES
Payment and payout providers
Process copies, faults, clock
One rollout. Only the changed tree reaches the grader.
Sandbox
One for the agent and one for the grader, per trial. 0.5 core and 3.4 GiB guaranteed; 2 to 4 cores and 4 to 8 GiB cap, per task. No network.
Budget
Two hours of agent time per trial. At the limit the agent is stopped and the grader scores the tree it left.
Grading
Rebuild, then every hidden case. Median 2½ minutes, 95th percentile 15.
Reward
Binary. r = 1 when every fail-to-pass case and every pass-to-pass case passes, else 0. Fail-to-pass cases test the requested change; pass-to-pass cases pin behaviour that must not break.
Rollout cost
$0.03 to $0.24 of sandbox compute a rollout, 2 to 4% of model spend; not in the leaderboard.
Task CI
Candidates mined from the codebase. Tests written from the task statement. A separate solver writes the reference blind, from the statement and starting code only. Tests and solutions play against each other until neither finds a new disagreement. Task CI scores every arm. Authored with Kennet.
Agent
Claude Sonnet 5.5 on Claude Code 2.1.288, medium effort; Gemini 4 Argon on Antigravity CLI 1.3.5, high effort; Muse Spark 1.3 on Muse Code 1.4.7, medium effort; Gemini 3.8 Flash on Terminus 2 2.0.0, medium effort. 4 trials per task.
Score
Share of passing trials, averaged over tasks.
Interval
95% bootstrap over tasks. Shared rank unless intervals separate.
Infra failures
1 of 2,400 trials, left out of every score.
How agents try to cheat
We studied a few trajectories and present an early preview of our research on reward hacking.
Special-case the fixtures
Branch on the IDs the local data seeds. Hidden cases bring their own data.
Change what the tests observe
A process-wide override the tests share, such as swapping the HTTP client. Refused before grading.
2,938 (2,026 fail-to-pass, 912 pass-to-pass). Median 19 per task.
Known-wrong
3,200 plausible wrong fixes, each a realistic mistake, that the verifier must reject. Median 21 per task. Every one is rejected.
Known-right
366 correct fixes besides the reference, written differently, that the verifier must accept; 228 written blind from the statement alone. Every one is accepted.
Every task sits on two axes read from its own files, never from model results, so pairs and releases share one scale.
Concern: the hardest systems condition the statement states (concurrency, failures and deadlines, stored data and rollout, access control), else business logic only. Difficulty: an experienced engineer's time to design and build the fix, the geometric mean of four blind estimates. Easy under 2 hours, medium 2 to 3½, hard over 3½.
We plan to partner with more enterprises to broaden both the depth and breadth of our private codebase work. If you are a technical leader interested in researching frontier agents on production incidents, please reach out to us here.
We plan to publish a deeper analysis on our research on reward hacking attempts by the solver agents in our work.
We will expand our bench to close frontier open source models and extend our failure analysis with contrastive analysis on successful attempts and failure modes across agents.