Should I use owlwarden instead of Semgrep?

Usually not. Semgrep has thousands of rules across many languages; owlwarden has 25, runs offline with no account, gives a fix written for your framework, and reads the agent and editor configuration Semgrep does not.

Does owlwarden need an account or a cloud service?

No. It runs entirely on your machine and constructs no network transport at all unless you pass --osv or --target.

owlwarden and Semgrep

owlwarden vs Semgrep

The tools cover different jobs. The table compares scope and default behavior so you can decide whether to run one or both.

See owlwarden rules Review the gaps

CapabilitySemgrepowlwarden

Rule breadthThousandsFocused

LanguagesManyJS / TS

Agent configNoYes

Default runVariesOffline

Scope and defaults differ. Run both when you need both sets of checks.

What Semgrep covers

Rule breadth. Thousands of rules across many languages. owlwarden has 25 rules for Node applications and agent config.
Custom rules. A mature pattern language with a large public registry. owlwarden's plugin tier is source-only WASM with a fixed v1 API.
Language coverage. Python, Go, Java, C#. owlwarden is JavaScript and TypeScript.

What owlwarden adds

Agent configuration. .claude/settings.json, .vscode/tasks.json, and .cursor/hooks.json.
Offline with no account. No login, no upload, no policy service. The default run constructs no transport at all.
Framework-specific fixes. Findings include corrected code for the detected API.
Agent hooks. Host events run checks automatically.

Running both

semgrep --config auto        # broad rule coverage
owlwarden scan --since origin/main   # Node and agent config

Both emit SARIF, so both land in the same code-scanning view. The exit-code contract is here.

Other comparisons

All rules / Coverage, gaps included / Offline