Cejel MCP server

cejel

Cejel ("SEH-jel") — a trust certificate for your codebase.

Free, offline, no-signup CLI that scores the engineering signals that tell you whether to trust a repo — tests, secrets, isolation, claim-vs-reality, CI/audit discipline — and prints a trust certificate + badge. Especially valuable when AI wrote a lot of the code: that's exactly when you can't eyeball trust. Built on a deterministic, no-LLM scoring core — the free path makes zero network calls and requires no account.

Claim boundary: Cejel scores engineering-trust signals; it does not claim to detect software defects or prove that code is safe. Defect and vulnerability scanners remain evidence producers that Cejel can aggregate into a trust certificate.

Cejel is not another point scanner competing with the one you already run — it's the open, portable, offline trust certificate that aggregates them. Pipe in SARIF-compatible output (MunaTrust, Snyk, Semgrep, CodeQL, Codex) plus OpenSSF Scorecard, and get one shareable certificate + badge over all of them. See "Aggregate your scanners" below.

Cejel is used on Barg Labs’ own code. The public board

labels publisher-owned snapshots separately from the ranked public repositories.

Rubric calibration policy

The public CLI default is witan-rubric-v17-2026-07-24, the last rubric to clear Cejel's preregistered 200-repository untouched holdout. Published calibration figures apply only to that exact rubric and frozen evaluation population. Later rubrics—including the current v18 through v23 prospective series—are available only to explicit evaluation harnesses. Prospective rubrics inherit none of v17's calibration figures; a bounded paired repair or corpus-delta result can validate its stated construction without transferring precision, recall, or false-positive-rate claims. Promoting a prospective rubric to the public default requires a fresh authenticated untouched holdout, every preregistered gate to pass, and a separately recorded promotion decision.

Measured recall (bounded)

Measured recall (bounded). Cejel publishes one cohort-level in-scope detection-recall

figure, for the prospective v22 rubric, in docs/calibration/v22-detection-recall/; no general

figure exists, and the three quantities called recall are set side by side on

cejel.dev/methodology. On a frozen,

preregistered, in-scope held-out fixture set of 30 named defects, the released public default

(v17, tree a857f0b3) cited 16/30, two-sided 95% Wilson interval [36.1%, 69.8%]; the

prospective v22 detector (commit 8a289ea, tree 10960a03) cited 24/30, two-sided 95%

Wilson interval [62.7%, 90.5%]. Same fixtures, same partition, same controls in both runs.

v22 is prospective and not the shipped default. Full preregistrations and results:

docs/experiments/in-scope-detection-recall-v3-result-2026-08-09.md and

docs/experiments/in-scope-detection-recall-v4-result-2026-08-11.md.

The defect-class census publishes the coverage-breadth boundary—which defect classes any shipped rule targets—and is explicitly not a recall claim.

Install

No account, no key, no signup.

Single-file binary. One file. No Node, no npm, no node_modules, nothing installed.

Shortened. The full README is on GitHub.