Comparisons: Meridian vs Semgrep vs GHAS vs SonarQube vs Snyk¶
This is a deep, honest comparison. The other tools are good at what they do — but they are built around a different assumption: find and report. Meridian is built around find and block, then keep the record.
At a glance¶
| Capability | Meridian | Semgrep (Team) | GitHub Advanced Security | SonarQube | Snyk |
|---|---|---|---|---|---|
| Primary model | Blocking gate | Advisory SAST | Advisory (cloud) | Advisory quality/SAST | Advisory SCA/SAST |
| Blocks the deploy by default | Yes | No | No | No | No |
| Per-diff RFC artifact | Yes | No | No | No | No |
| WORM audit trail | Yes | No | No | No | No |
| LLM reasoning layer | Yes | No | No (Copilot is separate) | No | Partial (AI features) |
| Regex/pattern rules | Yes | Yes (strong) | Yes (CodeQL) | Yes | Yes |
| Structural/AST rules | Yes (Semgrep-compatible) | Yes (strong) | Yes (CodeQL, strong) | Yes | Yes |
| Self-hosted | Yes | Partial | No (cloud) | Yes | No |
| Air-gap capable | Yes | No | No | Partial | No |
| License | Apache-2.0 | Proprietary (OSS engine exists) | Proprietary | LGPL / Commercial | Proprietary |
| Indicative price | $0 | ~$450/mo | $19/seat/mo | $150+/mo | Quote-based |
Prices are indicative public figures and change; verify with each vendor. The structural differences (block vs advise, RFC, WORM, air-gap) are the durable points.
vs Semgrep¶
Semgrep's rule engine is excellent and Meridian's Gate 2 is Semgrep-compatible by design — you can bring Semgrep-style rules. The difference is the surrounding model:
- Semgrep reports findings; acting on them is up to your pipeline configuration. Meridian is the gate and refuses the change.
- Semgrep Team is a paid SaaS; Meridian is Apache-2.0 and self-hosted.
- Neither Semgrep tier produces an RFC or a WORM trail.
When to prefer Semgrep: you want the deepest, most mature rule library and are happy treating output as advisory. When to prefer Meridian: you want hard blocking + an auditable RFC + LLM review + air-gap.
vs GitHub Advanced Security (CodeQL)¶
CodeQL is powerful and deeply integrated into GitHub — but:
- Cloud-only. GHAS cannot run air-gapped; your code is analysed in GitHub's environment. For regulated/offline shops this is a non-starter.
- Per-seat pricing ($19/seat/mo) scales with team size; Meridian is $0.
- Advisory by default; you build branch-protection around it (which Meridian also supports, but Meridian's gate is the product, not an add-on).
- No WORM RFC artifact.
When to prefer GHAS: you are all-in on GitHub cloud and want CodeQL's depth. When to prefer Meridian: you need self-hosting/air-gap, blocking-by-design, and a tamper-evident record.
vs SonarQube¶
SonarQube is a code-quality and SAST platform with quality gates. Its "quality gate" can fail a build — closer to Meridian than the others — but:
- SonarQube's focus is broad code quality (smells, coverage, duplication) more than AI-specific risk.
- The paid tiers start around $150+/mo; Meridian is $0.
- No per-diff RFC + WORM trail with override-with-reason semantics.
- No tiered LLM reasoning layer.
When to prefer SonarQube: you want a comprehensive quality platform and coverage tracking. When to prefer Meridian: you want a focused, blocking change gate for (especially AI-generated) risk with an auditable decision record.
vs Snyk¶
Snyk is strongest at software composition analysis (dependencies/vulnerabilities) and has SAST + AI features. Meridian does not do SCA — it reviews your diff, not your dependency tree. These are complementary:
- Use Snyk (or any SCA) for dependency/vuln management.
- Use Meridian as the blocking change gate with RFC + WORM for the code change itself.
Honest summary¶
Meridian is not "better than" these tools across the board — they have larger rule libraries, more integrations, and years of polish. Meridian wins on a specific, unusual combination that none of them offer together:
- Blocks (not advises) by design,
- produces a per-diff RFC,
- keeps a WORM audit trail,
- adds an LLM reasoning layer,
- is self-hosted, air-gap capable, and Apache-2.0 ($0).
If you do not need blocking, an audit trail, or air-gap, one of the incumbents may serve you better. If you do — especially for AI-generated code in a regulated or cost-sensitive setting — that combination is the reason Meridian exists.
Next: Further reading