---
license: mit
task_categories:
  - text-generation
language:
  - en
tags:
  - solidity
  - smart-contracts
  - code-generation
  - agentic-eval
  - foundry
  - differential-fuzzing
size_categories:
  - 1K<n<10K
configs:
  - config_name: lite
    data_files:
      - split: train
        path: lite/train-*
  - config_name: full
    data_files:
      - split: train
        path: full/train-*
    default: true
---

# Solidity Eval (2026)

Agentic Solidity benchmark. Each task hands the agent a Foundry workspace where one function body in a real Etherscan-verified contract has been replaced with `revert("TODO");`. The agent edits, builds (`forge build`), and tests (`forge test`) inside a sandbox until it returns. Reward is the differential-fuzz pass rate (Diffusc + Echidna) of the model's body against the ground-truth body.

This dataset is intended for use with the [hermes-agent](https://github.com/NousResearch/hermes-agent) Solidity Eval environment, but the `workspace_tar` / `scoring_tar` shape is harness-agnostic — any agent harness that can stage a tarball into `/work` and run a scorer over `/scoring` can use it.

## Reference baseline

All scores are **pass@1** under SolBench's `echidna()` rule: per task, a single agentic attempt is scored as 1.0 only if Diffusc compiles the candidate AND Echidna's differential-fuzz finds no behavioral divergence vs. the ground-truth body (or the harness vacuously passes), AND the B3 canary check + stub-residue guard both pass. Slither runs but is recorded as a side metric only — this is **not** Vul@k. No resampling (`group_size=1`).

| Agent / model | Split | pass@1 | Wall-clock | Notes |
| --- | --- | --- | --- | --- |
| **Qwopus 3.6 27B Solidity (stage4-rft)** | `lite` | **46.5%** (93/200) | ~27 min | Local serve via vLLM TP=2 FP8 (qwen3_xml tool parser) on 2× Blackwell GPUs. Hermes agent loop (in-process tool dispatch). Same fuzz settings + sandbox image as below. |
| Claude Code 2.1.128 (Claude Opus 4.7) | `lite` | 39.0% (78/200, 1 timeout) | ~34 min | Anthropic API via Claude Code CLI inside the sandbox. CLI agent backend. |

**Identical conditions across both rows:** lite split (200 tasks), 16-way concurrency, `max_agent_turns=40`, `max_token_length=32000`, `agent_temperature=0.6`, `fuzz_timeout_s=300`, `fuzz_test_calls=50000`, `fuzz_seed=0xDEADBEEF`, reference sandbox image (`samscrack/solidity-eval-sandbox:dev` extended with the symlink fix below — Claude Code row also adds the Claude Code CLI to the image), `terminal_backend=docker` on the same 32-core host. Run via `hermes-agent`'s `solidity_eval` environment.

A non-trivial fraction of failures on `lite` come from B3 canary false-positives where the deleted function legitimately requires common Solidity primitives (`keccak256`, `encodePacked`, addresses unsorted via `sortTokens`, etc.). The ground-truth canary list is generated by token-overlap with the deleted function body and was not pruned for these false-positives in the v0 build; this is the dominant source of noise on the `lite` baseline. Filter to rows where the canary set excludes those tokens if you want a less-noisy slice.

## Configs

| Config | Rows | Selection |
| --- | --- | --- |
| `lite` | 200 | Stratified by pragma major.minor over the full cohort (seed=0). Use this for cost-bounded eval runs. |
| `full` | 3044 | Every row from the SolBench RACR-4k corpus that (a) has a parseable Solidity pragma, (b) satisfies the 0.5.0–0.8.34 compiler range installed in the reference image, and (c) parses cleanly through the function-stubbing step. |

## Schema

| Field | Type | Description |
| --- | --- | --- |
| `task_id` | str | `<contract_name>_<idx>`, unique within the dataset. |
| `domain` | str | `"unknown"` for every row — the source corpus has no domain mapping. |
| `contract_name` | str | Solidity contract name (target of the deletion). |
| `contract_address` | str | Etherscan address the source was scraped from. |
| `pragma` | str | Raw pragma string from the source (`^0.8.10`, `>=0.6.0 <0.8.0`, etc.). |
| `pragma_major_minor` | str | `"0.5"` / `"0.6"` / `"0.7"` / `"0.8"` — used for stratification. |
| `resolved_solc_version` | str | Highest installed solc satisfying the pragma. The reference image installs every patch version of 0.5.x–0.8.x. |
| `target_function_signature` | str | First line of the deleted function header (for the prompt). |
| `prompt_context` | str | Surrounding code shown to the model (`sc_ba[0]` from the source corpus). |
| `workspace_tar` | str | Base64-encoded `.tar.gz` containing `foundry.toml` + `src/<contract_name>.sol` (with the target function body replaced by `{ revert("TODO"); }`). Stage this into `/work` before the agent runs. |
| `scoring_tar` | str | Base64-encoded `.tar.gz` containing `manifest.json` + `origin/<contract_name>.sol`. Stage into `/scoring` *only at scoring time* — never during the agent loop. |
| `canary_substrings` | list[str] | Tokens / fragments unique to the deleted function body. The scorer fails the run with `b3_violation` if any of these appear in `/work` after the agent finishes. |

## Reward semantics

The in-image scorer (`/opt/scoring/run_diffusc.py` in the reference image) follows SolBench's `echidna()` rule:

```
reward = 1.0 if Diffusc compiles + Echidna passes (or vacuous "no diff" pass)
reward = 0.0 on diffusc compile failure, echidna failure, timeout,
              B3 canary violation, or stub-residue (revert("TODO"); left in)
```

Three pass routes are tagged in `pass_route.txt` for auditability: `exit_0`, `vacuous_no_diff`, `fail`. Runs with disproportionate vacuous passes can be flagged.

## B2 / B3 reward-hack mitigations

- **B2 (no exfiltration via web tools).** The verified contracts are public on Etherscan, so any agent with web access can fetch the answer with one query. Runners must disable web/browser/messaging tools; for non-Hermes agents this means setting agent-specific flags or running the sandbox container without network egress.
- **B3 (no ground-truth in the workspace).** `scoring_tar` (containing `origin/`) is staged only after the agent loop ends. The scorer additionally greps the candidate for `canary_substrings` and zeroes the reward if any match.
- **Stub residue.** If the agent leaves `revert("TODO");` in the candidate, the scorer flags it (`pass_route=stub_residue`) and zeros the reward — otherwise an empty implementation would coast through the vacuous-pass route.

### B3 caveats

- 168 of the 3044 rows have an empty `canary_substrings` list (the deleted body uses only identifiers that already appear elsewhere in the contract — common for ERC20-style getters). For these rows B3 enforcement degrades to best-effort; the canary-grep is a no-op and only the stub-residue + diff-fuzz checks remain. Auditors who want strict B3 enforcement should filter to rows with non-empty canaries.

## Running it yourself

The dataset is harness-agnostic: any agent runner that can stage two tarballs and exec a Python scorer inside a sandbox container can use it. The only fixed contract is the layout the scorer expects:

```
/work/                         <- agent's editable workspace
  foundry.toml
  src/<contract_name>.sol      <- target file; one function body is `revert("TODO");`

/scoring/                      <- never visible during the agent loop (B3)
  manifest.json                <- resolved_solc_version, contract_name, fuzz settings, canaries
  origin/<contract_name>.sol   <- ground-truth contract

/logs/verifier/                <- scorer writes results here
  reward.txt                   <- single float in [0, 1]
  scoring_log.txt
  diffusc_stdout.txt / diffusc_stderr.txt
  echidna_stdout.txt / echidna_stderr.txt
  b3_violation.txt             <- present iff B3 canary check fired
  slither.txt                  <- side metric (not used in reward)
```

### Step-by-step

```python
from datasets import load_dataset
import base64, io, tarfile, json, pathlib

ds = load_dataset("samscrack/solidity-eval-2026", "lite", split="train")
row = ds[0]

# 1. Stage the workspace into /work BEFORE the agent runs.
ws = base64.b64decode(row["workspace_tar"])
with tarfile.open(fileobj=io.BytesIO(ws), mode="r:gz") as t:
    t.extractall("/path/to/sandbox/work")

# 2. Run your agent against /work (forge build / forge test / edit /work/src).
#    Disable web/browser tools (B2 — verified contracts are public on Etherscan).
#    Do NOT mount or expose /scoring during this step.
run_my_agent(workspace="/path/to/sandbox/work", prompt=row["prompt_context"])

# 3. After the agent returns, stage the scoring assets and run the scorer.
sc = base64.b64decode(row["scoring_tar"])
with tarfile.open(fileobj=io.BytesIO(sc), mode="r:gz") as t:
    t.extractall("/path/to/sandbox/scoring")

# 4. Run the in-image scorer. Use the reference image as-is.
#    (The same container used for the agent loop is fine — see "Sandbox tips" below.)
#    docker run --rm \
#      -v /path/to/sandbox/work:/work \
#      -v /path/to/sandbox/scoring:/scoring \
#      -v /path/to/sandbox/verifier:/logs/verifier \
#      samscrack/solidity-eval-sandbox:dev \
#      python /opt/scoring/run_diffusc.py

reward = float(pathlib.Path("/path/to/sandbox/verifier/reward.txt").read_text().strip())
```

### Reference scorer image

```
samscrack/solidity-eval-sandbox:dev
```

Bundles Foundry 1.6.0-nightly, Echidna 2.2.3 (SolBench fork), Diffusc + Slither 0.9.3 (`webthethird/slither.git@dev-diffusc-testing`), solc-select with every patch of 0.5.x–0.8.x installed, and `/opt/scoring/run_diffusc.py`.

A standalone smoke test that does not depend on a harness is included at the eval repo's `scoring-smoke/run_scoring_smoke.sh`: it builds an identical-candidate (`reward=1`) and a wrong-direction-candidate (`reward=0`) case and runs the scorer on each.

### Sandbox tips (lessons from running this end-to-end)

1. **Persist the same sandbox container across staging → agent → scoring.** Each phase uses different tarballs, but the container's filesystem is the only place that links them. Don't tear down the container between phases — the agent's edits to `/work/src/<C>.sol` are exactly what the scorer reads.

2. **The reference image stores solc-select state at `/root/.solc-select`** and exposes it via a symlink at `/opt/py/.solc-select`. If your harness bind-mounts `/root` (e.g. for an isolated agent home dir), that symlink breaks and the scorer fails on `solc-select use <X>`. Either:
   - don't bind-mount `/root`, or
   - layer a derived image that materializes the symlink:
     ```dockerfile
     FROM samscrack/solidity-eval-sandbox:dev
     RUN test -L /opt/py/.solc-select && \
         cp -a /root/.solc-select /opt/py/.solc-select.real && \
         rm /opt/py/.solc-select && \
         mv /opt/py/.solc-select.real /opt/py/.solc-select
     ```

3. **The agent loop budget should comfortably exceed any single command timeout your harness enforces.** Echidna fuzzing runs up to `fuzz_timeout_s` (default 300s) in `manifest.json`; the scorer wrapper adds compile/setup overhead. A 600s foreground-command cap will silently kill scoring mid-run. Configure ≥ `fuzz_timeout_s + 120`.

4. **CLI agents (Claude Code, aider, etc.) shouldn't receive the prompt as a command-line argument.** The 14–18 KB prompts contain Solidity code with substrings (` & `, `&&`, `;`) that trip many "is this a long-lived process / dangerous command" guards even inside shell quotes. Pipe the prompt via stdin or pass it as a file path:
   ```bash
   claude --print --max-turns 40 < /work/.agent_prompt.md
   ```

5. **Reference image rebuild for embedded-CLI agents.** If you want to run a coding-agent CLI (Claude Code, aider) inside the sandbox, layer it on top of the reference image and apply the symlink fix from (2) at the same time. Example for Claude Code:
   ```dockerfile
   FROM samscrack/solidity-eval-sandbox:dev
   RUN apt-get update && apt-get install -y --no-install-recommends curl ca-certificates gnupg \
    && curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
    && apt-get install -y --no-install-recommends nodejs \
    && rm -rf /var/lib/apt/lists/* \
    && npm install -g @anthropic-ai/claude-code
   RUN test -L /opt/py/.solc-select && \
       cp -a /root/.solc-select /opt/py/.solc-select.real && \
       rm /opt/py/.solc-select && \
       mv /opt/py/.solc-select.real /opt/py/.solc-select
   ```

## Provenance

- Source corpus: SolBench (https://github.com/ZaoyuChen/SolBench, MIT, FSE 2026), specifically the RACR-4k LCS subset.
- Function-stubbing + tarball construction: this dataset's builder (`environments/benchmarks/solidity_eval/dataset/build_modern_subset.py` in the eval repo).
- Reference scorer + sandbox image: `samscrack/solidity-eval-sandbox:dev` (Foundry 1.6.0-nightly, Echidna 2.2.3 from the SolBench fork, Diffusc + Slither 0.9.3 from `webthethird/slither.git@dev-diffusc-testing`, solc-select 0.5.0–0.8.34).

## Skipped rows from the source corpus (164 of 3208)

| Reason | Count |
| --- | --- |
| `cannot-stub-funit` | 143 |
| `unsupported-pragma-0.4` | 8 |
| `no-pragma` | 13 |

`cannot-stub-funit` covers constructors, modifiers, receive/fallback declarations, and abstract function shapes the regex-based stubber can't safely rewrite. Future builder iterations could handle these explicitly.

## License

MIT, inherited from SolBench. The contract sources are public on Etherscan.