CanCodex /goalrebuild programs from scratch?

GoalBench

Given only a compiled binary and its documentation, the agent must architect and implement a replacement CLI that reproduces the original program's behavior. We score each submission with ProgramBench's behavioral tests.

Generated 2026-05-21 22:32 UTC 597 evaluated instances 200 tasks in full ProgramBench Sorted Resolved → Almost → Avg. pass
Leaderboard

Current Results

#ModelRunAgentResolvedAlmostAvg. est. costAvg. callsAvg /goalMax /goal
1 GPT 5.5 (xhigh) 20260517T094700Z Codex /goal 0.5% (1/200) 6.0% (12/200) $4.89 80.2 14.7m 27.2m
2 GPT 5.5 (xhigh) 20260518T232006Z Codex /goal 0.0% (0/200) 0.5% (1/200) $3.54* 59.5 11.4m 25.6m
3 GPT 5.5 (xhigh) 20260519T215046Z Codex /goal 0.0% (0/197) 0.0% (0/197) $3.95* 67.7 13.2m 22.5m
Run summary
GPT 5.5 (xhigh) · Mini-SWE-compatible no internet · 20260517T094700Z
Codex /goal mini-SWE-compatible no-internet · smaller VM: 16 CPU / 30g · version 20260517T094700Z
200instances
0.5%resolved
6.0%almost
63.6%avg pass
$977est. from token logs
16,038total calls
$4.89est. cost / costed task
80.2calls / task
14.7mavg /goal session
27.2mmax /goal session
GPT 5.5 (xhigh) · Paper prompt + /goal no internet · 20260518T232006Z
Codex /goal paper prompt no-internet, mini-SWE-style execution · smaller VM: 16 CPU / 30g · version 20260518T232006Z
200instances
0.0%resolved
0.5%almost
53.4%avg pass
$142*token logs for 40/200 tasks
11,900total calls
$3.54*est. cost / costed task
59.5calls / task
11.4mavg /goal session
25.6mmax /goal session
GPT 5.5 (xhigh) · Paper prompt + Goal contract no internet · 20260519T215046Z
Codex /goal contract no-internet, mini-SWE-style execution · smaller VM: 16 CPU / 30g · version 20260519T215046Z
197instances
0.0%resolved
0.0%almost
52.5%avg pass
$158*token logs for 40/197 tasks
13,337total calls
$3.95*est. cost / costed task
67.7calls / task
13.2mavg /goal session
22.5mmax /goal session
Latency

Goal Session Duration

Wall-clock time is measured per Codex /goal session from launch to packaged submission. ProgramBench's public mini-SWE-agent runs use a much larger timeout, so this block makes latency differences explicit.

Average0.244h14.7 min
Median0.234h14.0 min
P750.281h16.9 min
P900.329h19.8 min
P950.363h21.8 min
Max0.454h27.2 min
Over 6h0 / 2000.0%
<15 min 121 / 200 60.5%
15-30 min 79 / 200 39.5%
>30 min 0 / 200 0.0%

Longest task: hairyhenderson__gomplate.05eb3aa at 27.2 min.

Official Baseline Context

For orientation only. ProgramBench's public extended table reports mini-SWE-agent over 200 tasks, sorted by resolved, almost-resolved, then average pass rate.

#ModelAgentResolvedAlmostAvg. costAvg. calls
1 GPT 5.5 (xhigh) mini-SWE-agent 0.5% 13.5% $8.85 82
2 GPT 5.5 (high) mini-SWE-agent 0.5% 5.0% $3.65 41
3 Claude Opus 4.7 (xhigh) mini-SWE-agent 0.0% 4.5% $10.96 159
4 Claude Opus 4.7 mini-SWE-agent 0.0% 3.0% $3.81 93
5 Claude Opus 4.6 mini-SWE-agent 0.0% 2.5% $11.38 260
6 GPT 5.5 mini-SWE-agent 0.0% 1.5% $1.21 19
7 Claude Sonnet 4.6 mini-SWE-agent 0.0% 1.0% $26.73 472
8 GPT 5.4 mini-SWE-agent 0.0% 0.0% $0.33 16
9 Gemini 3.1 Pro mini-SWE-agent 0.0% 0.0% $1.51 94
10 Gemini 3 Flash mini-SWE-agent 0.0% 0.0% $0.30 85
11 Claude Haiku 4.5 mini-SWE-agent 0.0% 0.0% $0.80 124
12 GPT 5.4 mini mini-SWE-agent 0.0% 0.0% $0.04 18
13 GPT 5 mini mini-SWE-agent 0.0% 0.0% $0.03 15

GPT-5.5 baseline rows link to ProgramBench's official run-detail pages for total cost, total calls, distribution plots, and all 200 per-instance results.

Method Notes

GoalBench reports separate Codex /goal runs on ProgramBench tasks; these are not official mini-SWE-agent leaderboard submissions. Resolved means ProgramBench's filtered behavioral pass rate is exactly 100%, and almost resolved means at least 95%.

GoalBench currently keeps three public prompt tracks separate: mini-swe-compatible-nointernet for the already-published mini-SWE-compatible result, paper-prompt-nointernet for the ProgramBench paper prompt with /goal and mini-SWE-style execution, and paper-prompt-goal-contract-nointernet for the same scaffold with an explicit Codex Goal contract.

GoalBench uses a host-side wrapper to transport allowed black-box CLI interactions into the target container. This differs from mini-SWE-agent's in-container execution, but the wrapper is restricted to normal user-interface observations of the target executable and forbids source lookup, binary reading, disassembly, tracing, instrumentation, and evaluator/test access.

The public table is scoped to the latest published result set. Cost is estimated from Codex token logs, not billing; rows marked n/a or aggregate costs marked * have incomplete local token-log coverage, so calls are the more complete compute proxy for those tracks. See Task Details and the runbook for scoring, evidence, egress, and setup details. Sources: ProgramBench extended results and GPT 5.5 xhigh run detail.