Big Pickle on SWE Atlas – Codebase QnA
Summary
Big-pickle, a free stealth AI model, achieved a 50.8% resolve rate on Scale AI's SWE Atlas Codebase QnA benchmark using the mini-swe-agent scaffold, outperforming other models in its class.
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PhillipChaffee/big-pickle-swe-atlas
Source: https://github.com/PhillipChaffee/big-pickle-swe-atlas
Big Pickle on SWE Atlas — Codebase QnA
Task Resolve Rate: 50.8% (63/124) — big-pickle, the free stealth model on OpenCode Zen, evaluated on Scale AI’s SWE Atlas Codebase QnA benchmark using the mini-swe-agent scaffold.
Run on 2026-08-11 with the official open-source harness, task data, and judge model.
Result in context
Against the official SWE Atlas QnA leaderboard (updated 2026-07-28):
| Model (scaffold) | Task Resolve Rate |
|---|---|
| Opus 5 (Claude Code, xHigh) | 63.17 |
| Opus 4.8 (Claude Code, xHigh) | 57.26 |
| big-pickle (Mini-SWE-Agent) — this run | 50.81 |
| GLM 5.2 (Mini-SWE-Agent) | 48.12 |
| GPT-5.6-Sol (Codex, xHigh) | 46.00 |
| GPT 5.5 (Codex, xHigh) | 45.43 |
Within the Mini-SWE-Agent scaffold class — the apples-to-apples comparison — this run outscores every entry on the official leaderboard, and it also tops the Codex-scaffold GPT entries. Only the two Claude models running on their native Claude Code scaffold score higher. Note the caveats below before treating this as a leaderboard-equivalent number.
By language
| Language | Resolved | Rate |
|---|---|---|
| TypeScript | 18/31 | 58.1% |
| Python | 16/29 | 55.2% |
| Go | 19/38 | 50.0% |
| C | 10/26 | 38.5% |
By category
| Category | Resolved | Rate |
|---|---|---|
| Code Onboarding | 17/28 | 60.7% |
| Architecture & system design | 23/44 | 52.3% |
| Root-cause analysis | 17/37 | 45.9% |
| Security | 5/11 | 45.5% |
| API & library usage / integration | 1/4 | 25.0% |
Method
Everything follows Scale’s published protocol as closely as budget allowed:
- Tasks: all 124 Codebase QnA tasks from scaleapi/SWE-Atlas (Apache-2.0), unmodified — including Scale’s shipped
mswea_qa_config.yamlagent configuration (system/instance templates,step_limit: 250). - Harness: Harbor v0.18.0 with Modal sandboxes, per the SWE-Atlas README.
- Scaffold: mini-swe-agent pinned to 2.4.6 — the same minimal bash-only scaffold Scale uses for non-first-party models on the leaderboard.
- Model:
big-picklevia OpenCode Zen’s OpenAI-compatible endpoint (https://opencode.ai/zen/v1), litellm routeopenai/big-pickle. Total consumption: 674M input / 4.3M output tokens, at $0 (the model is free during its stealth period). - Judge:
claude-opus-4-5-20251101— the exact judge model Scale specifies — accessed through Anthropic’s OpenAI-compatible endpoint (https://api.anthropic.com/v1) withEVAL_MODELoverridden to the bare Anthropic model ID. - Scoring: the benchmark’s own rubric-based verifier, unmodified. A task resolves only if every scored must-have rubric passes.
Caveats
Read these before quoting the number:
- Single trial per task (
-k 1). The official protocol runs 3 trials and reports the mean. At n=124, the single-trial standard error is ≈ ±4.5 points — comparable to the leaderboard’s own reported error bars (±5). - Reduced sandbox resources. Tasks declare 16 CPU / 16 GB; this run used 4 CPU / 8 GB to fit a personal budget. Slower command execution can only depress an agent’s score (via command timeouts or OOM kills), not inflate it. Empirically it appears to have had no effect here: a scan of all 124 agent trajectories found zero command timeouts and zero exit-137 kills — no command ever hit the 900s ceiling or the memory limit.
- Self-reported. Scale did not run or verify this evaluation. The full per-task verifier logs in this repo allow independent auditing, and the run is reproducible from the configs here plus the public SWE-Atlas repo.
- Model identity unknown. big-pickle is officially unconfirmed; leaked provider errors and API response signatures suggest it is currently served by DeepSeek infrastructure. The underlying model may change without notice, so this result is a snapshot of whatever was behind the alias on 2026-08-11.
- Data exposure. OpenCode states that prompts to big-pickle during its free period may be used to improve the model. The benchmark’s task content (already public, canary-marked by Scale) was necessarily sent to that endpoint.
- Two resolved tasks had unscored rubrics. On
task-...ba9ad(5 of 11 rubrics) andtask-...baa1d(1 rubric), the judge returned unparseable output through all 8 retries; the benchmark’s verifier excludes unscored rubrics from the pass computation by design. Treating unscored-as-fail instead gives a strict-lower-bound of 61/124 = 49.2% — still above every Mini-SWE-Agent leaderboard entry. All verifier logs are included so you can apply either convention.
Reproducing
git clone https://github.com/scaleapi/SWE-Atlas && cd SWE-Atlas
git clone --branch v0.18.0 --depth 1 https://github.com/laude-institute/harbor.git
uv tool install ./harbor --with modal && uv tool install modal && modal setup
# from this repo: copy run_config/qa, run_config/tw, run_config/rf into
# SWE-Atlas/run_config/ (preserving the subdirectories — the scripts resolve
# .env and Scale's mswea_*_config.yaml relative to their own location),
# copy preflight.sh and .env.example into the SWE-Atlas root,
# create .env from .env.example, then:
./preflight.sh
bash run_config/qa/big-pickle_smoke.sh # 3-task smoke test first
bash run_config/qa/big-pickle_miniswe.sh # full 124-task run
Hard-won gotchas the configs already handle:
- Do not pass
--ak reasoning_effortwith anopenai/-prefixed model — Harbor silently switches mini-swe-agent to the OpenAI Responses API, which chat-completions-only endpoints like Zen don’t serve. - Keep agent and judge credentials separate. The judge reads host
OPENAI_API_KEY/OPENAI_API_BASE(via each task’s[verifier.env]); the agent’s Zen credentials go through--aeper-agent overrides. - Pass secrets to
--aeas${VAR}templates, not literals. Harbor redacts literal secrets to****when persisting job state, which breaksharbor job resumewith instant 401s. Templates round-trip and re-resolve from the host env. - Expect a few % of trials to die to Modal
Failed to read exec stdio streamerrors;harbor job resume -f <ErrorType> ...re-runs them cleanly.
Approximate cost for the full QnA run: ~70 of Modal compute (at reduced sandbox resources; roughly 2–3× that at the declared 16 CPU/16 GB), ~25 of Anthropic API for judging, $0 for the model.
Repo contents
results/per_task_results.csv— task ID, category, language, resolved, aggregate rubric score, rubrics passed/totalresults/summary.json— headline numbers and breakdownsresults/verifier_logs/— the judge’s full per-rubric output for every task (audit trail). Notes like(flipped from raw=0)are the benchmark’s own shipped verifier logic (evaluate_answer.pyinverts rubrics marked negative-polarity), not post-hoc re-scoring.run_config/— the exact Harbor run scripts used (QnA smoke + full, plus untested Test Writing / Refactoring variants)preflight.sh— endpoint/auth checks for both the model and the judge
Attribution
- SWE Atlas benchmark © Scale AI, Apache-2.0 — paper: arXiv:2605.08366. Per the authors’ request, please treat SWE Atlas as a held-out signal of progress rather than a training target.
- Harbor (Laude Institute) and mini-swe-agent (SWE-agent team).
- big-pickle is served by OpenCode Zen.
Evaluation configs and results in this repo are MIT-licensed.
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