# circuit-work-budget

> Expanded source-operation estimate exceeds an explicit circuit work budget.

Canonical: https://nightshade.dicksonwu.xyz/rules/circuit-work-budget.html
Release: Nightshade 0.1.1 (v0.1.1)

| Field | Value |
| --- | --- |
| Rule ID | `circuit-work-budget` |
| Severity | low |
| Confidence | high |
| Maturity | experimental |
| Selection | Audit; needs policy |
| Policy intent | required |
| Default enabled | yes |
| Category | Policy-dependent rules |
| Engine facts used | cfg, resolved-calls, static-loop-bounds, work-policy |
| Release | v0.1.1 |

## Selection and scope

Selected by the default audit profile, but it stays dormant until `policies` in nightshade.json declares the matching application intent. Selecting it alone does not supply that intent.

```sh
./.nightshade/node_modules/.bin/nightshade ./contracts --detectors circuit-work-budget
./.nightshade/node_modules/.bin/nightshade detector show circuit-work-budget
```

The first command runs only this rule; `--detectors` takes a comma-separated list. The second prints the rule's metadata from your installed version.

Severity is review priority. It does not express exploitability or impact. Confidence is detector metadata, not a probability. All built-in rules are experimental.

Compiler scope: the engine supports the pinned profiles 0.28.0, 0.29.0, 0.30.0, 0.31.1, 0.33.0-rc.2, 0.34.0, 0.35.0-rc.1 and 0.35.0, with ZKIR2 by default. Support for this rule can be narrower; the rule documentation below states any narrower scope.

## Corpus checks

Synthetic corpus checks for this rule in the 0.1.1 proof run. A check counts only with compiler acceptance and complete analysis.

| Positive detected | Corrected quiet | Lookalike quiet | Other negative quiet | Incomplete |
| ---: | ---: | ---: | ---: | ---: |
| 2/2 | 2/2 | 1/1 | 0/0 | 0 |

No deviations were recorded for this rule.

These are behavior checks on synthetic fixtures, not a precision or recall estimate. See [evaluation](https://nightshade.dicksonwu.xyz/evaluation.md#synthetic-corpus).

## Rule documentation

From https://github.com/DicksonWu654/nightshade/blob/v0.1.1/docs/detectors/circuit-work-budget.md at v0.1.1.

Availability: **policy-required**; selected by default, but needs
`policies.workBudgets`. Severity **low**, confidence **high** for the source estimate.

Reports an expanded source-operation upper bound above a configured circuit
budget. The estimate expands static loops and callee work and conservatively
counts both branch alternatives.

### Example and review scenario

The compiler-qualified owned [fixture](#example-1)
repeats a Counter update four times. Its explicit review threshold is:

```json
{ "workBudgets": [{ "circuit": "update", "maxUnits": 5 }] }
```

Place this object under `policies` in the [configuration](https://github.com/DicksonWu654/nightshade/blob/v0.1.1/docs/configuration.md).
The [correction](#example-2) contains one update.
Use the rule to notice source-work growth beyond an agreed project limit.

Recommendation: inspect repeated loop and callee work, then measure actual
compiler/prover cost before optimizing or adjusting the budget. For an opt-in
fixed threshold without policy, see [circuit-cost](https://nightshade.dicksonwu.xyz/rules/circuit-cost.md).

### False positives and limitations

Intentional large circuits or conservative branch expansion can exceed a useful
application budget. Units are not proof rows, optimized compiler cost, runtime,
memory usage or prover time. A finding is not evidence of an attacker-controlled
unbounded loop or denial of service. An unavailable finite estimate emits an
incomplete diagnostic instead of passing the configured check. A configured
threshold is a project review limit, not a performance guarantee.

### Source examples

These short regression examples are included here for installed-package readers.
Rule-specific policy requirements and limits above still apply.

#### Example 1

Fixture (source: `tests/corpus/vulnerable/work-budget.compact`).

```compact
pragma language_version >= 0.26.0;
import CompactStandardLibrary;
export ledger count: Counter;
export circuit update(): [] {
  for (const index of 0..4) { count += 1; }
}
```

#### Example 2

Correction (source: `tests/corpus/safe/work-budget.compact`).

```compact
pragma language_version >= 0.26.0;
import CompactStandardLibrary;
export ledger count: Counter;
export circuit update(): [] {
  count += 1;
}
```

## Suppress a match

If a match is intentional, suppress it on the line before with the exact rule ID and a reason of at least eight characters:

```compact
// nightshade-disable-next-line circuit-work-budget -- Reason this match is intentional
```

Diagnostics cannot be suppressed, and an unmatched directive for a selected rule makes analysis incomplete. See [configuration](https://nightshade.dicksonwu.xyz/configuration.md#suppress-an-intentional-match) for fingerprint suppressions and baselines.

## References

- [Rule source document at v0.1.1](https://github.com/DicksonWu654/nightshade/blob/v0.1.1/docs/detectors/circuit-work-budget.md)
- [Catalog entry in rules.json](https://nightshade.dicksonwu.xyz/rules.json)
- [All rules](https://nightshade.dicksonwu.xyz/rules.md#policy-dependent-rules)
- [Limitations](https://nightshade.dicksonwu.xyz/limitations.md)