> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usefused.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Development standards

> Follow Harnest source-quality, testing, complexity, and audit requirements.

These rules apply to the Go CLI and engine and the Python compiler and runtime.

## Source properties

| Rule            | Requirement                                                                            |
| --------------- | -------------------------------------------------------------------------------------- |
| Complexity      | Maximum cyclomatic complexity of 10 per function or method                             |
| Shared behavior | Keep one source of truth                                                               |
| Boundaries      | Separate decisions from filesystem, process, network, database, and serialization code |
| Comments        | Explain policy, ordering, safety, and compatibility—not syntax                         |
| Database work   | Filter, project, order, and paginate in the datastore                                  |
| Query count     | Avoid one query per item; test batching and prefetching                                |

Extract a cohesive helper when a function exceeds the complexity limit. Do not hide branches or suppress the check.

Bounded filesystem discovery and decoding one validated document are not database queries. Keep them bounded and avoid repeated reads.

## Audit boundary

Runtime work that changes durable state must emit an OpenTelemetry audit signal after commit. Failed attempts need a correlated failure signal.

| Record                                          | Never record                    |
| ----------------------------------------------- | ------------------------------- |
| Operation and trigger                           | Prompts and results             |
| Outcome                                         | Credentials and headers         |
| Stable identifiers with a bounded set of values | Secret values and full payloads |

Compiler and CLI file changes are outside this audit boundary. Do not add a separate compiler telemetry stack without an explicit design.

## Test selection

| Change                                                                 | Required test     |
| ---------------------------------------------------------------------- | ----------------- |
| One behavior in one component                                          | Focused unit test |
| Compiler/backend, process, transport, datastore, or framework boundary | Integration test  |
| Released journey not proven at a smaller boundary                      | End-to-end test   |
| Query-backed behavior                                                  | Query-count test  |

Keep every `SKILL.md` at 400 words or fewer, including frontmatter. Put schemas, background, long examples, and conditional details in `references/`.

## Quality gate

```bash theme={null}
python -m pip install -e ".[all,quality]"
make quality
```

| Gate                   | Checks                                    |
| ---------------------- | ----------------------------------------- |
| Schemas                | JSON contracts are valid                  |
| Python and Go tests    | Behavior and integrations                 |
| Complexity             | Both languages stay at or below the limit |
| Formatting and vetting | Go formatting and `go vet`                |
| Offline integration    | Python plan through Go compile and deploy |
| Skill quality          | Entrypoint word limits and structure      |

Run the same gate before a pull request or release.