# simdjson/simdjson — health index 19/100 (Critical)

> Inspection of the public repository simdjson/simdjson by inspect.software. It holds a health index of 19 out of 100, placing it in the Critical band. The index is a signal derived from publicly visible practice, not a warranty, a security audit, or an endorsement, and it is independent of payment.

- Repository: https://github.com/simdjson/simdjson
- Report page: https://inspect.software/software/simdjson/simdjson
- Full JSON report: https://inspect.software/api/repositories/simdjson/simdjson/report
- Badge: https://raw.githubusercontent.com/inspect-software/badges/main/v1/s/simdjson/simdjson.svg
- Inspected: 2026-09-20
- Methodology: metrics 2.10.0, report schema 0.34.0 (https://inspect.software/methodology.md)

## Category summary

| Category | Weight | Index | Band |
|---|---|---|---|
| Vitality | 21% | 94/100 | Exceptional |
| Community & Adoption | 17% | 88/100 | Excellent |
| Sustainability & Governance | 23% | 61/100 | Moderate |
| Engineering Quality | 19% | 82/100 | Excellent |
| Security | 16% | 34/100 | At Risk |
| AI Readiness | 4% | 68/100 | Good |

The weighted overall 72 is calibrated to 86 on the published index scale (record calibration 2026-08-02). A dependency reported as a malicious package applies a 35% multiplier to weighted overall health and gives it a Critical ceiling of 19.

## Repository facts

| Field | Value |
|---|---|
| Description | Parsing gigabytes of JSON per second : used by Facebook/Meta Velox, the Node.js runtime, ClickHouse, WatermelonDB, Apache Doris, Milvus, StarRocks |
| Classification | library |
| Homepage | https://simdjson.org |
| Primary language | C++ |
| License | Apache-2.0 |
| Stars | 24,263 |
| Forks | 1,289 |
| Created | 2018-03-23 |
| Last push | 2026-09-20 |
| Latest release | v4.6.11 |
| Commits (last year) | 276 |
| Bus factor | 1 |
| Topics | json, json-parser, simd, avx2, sse42, neon, aarch64, arm64, vs2019, cpp11, gcc-compiler, clang-cl, clang, c-plus-plus, x64, json-pointer, avx512, loongarch, loongarch64, risc-v |

## Vitality — 94/100 (Exceptional)

Is the project alive — is code being written and are releases shipping? Weight: 21% of the overall index.

### Development activity — 97/100 (Exceptional)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Push recency | met | 36 / 36 | last push 0 days ago |
| Commit cadence | partial | 33.2 / 36 | 48/52 weeks with commits |
| Commit volume | met | 18 / 18 | 276 commits in the last year |
| OpenSSF Scorecard: Maintained | met | 10 / 10 | 30 commit(s) and 20 issue activity found in the last 90 days -- score normalized to 10 |

### Release discipline — 90/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ships releases | met | 27 / 27 | 100 releases published |
| Release recency | met | 36 / 36 | latest release 14 days ago |
| Release cadence | met | 27 / 27 | a release every ~15.6 days |
| OpenSSF Scorecard: Signed-Releases | not met | 0 / 10 | Project has not signed or included provenance with any releases. |

### Abandonment — 100/100 (Exceptional)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Project is still maintained | met | 100 / 100 | last human commit 2 days ago |

## Community & Adoption — 88/100 (Excellent)

Does the project have users, downloads, attention, and a welcoming setup for contributors? Weight: 17% of the overall index.

### Popularity & adoption — 98/100 (Exceptional)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Stars | met | 60 / 60 | 24,263 stars |
| Forks | met | 25 / 25 | 1,289 forks |
| Watchers | partial | 13.3 / 15 | 244 watchers |

### Community health — 77/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 22.5 / 22.5 | — |
| License | met | 22.5 / 22.5 | recognized license (Apache-2.0) |
| CONTRIBUTING guide | met | 18 / 18 | — |
| Code of conduct | not met | 0 / 13.5 | — |
| Issue template | not met | 0 / 7.2 | — |
| PR template | met | 6.3 / 6.3 | — |

## Sustainability & Governance — 61/100 (Moderate)

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep? Weight: 23% of the overall index.

### Maintainer resilience (bus factor) — 42/100 (Weak)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Bus factor | partial | 9 / 54 | 1 contributor(s) cover half of all commits |
| Commit distribution | partial | 9.3 / 22.5 | top contributor authored 59% of commits |
| Contributor breadth | met | 13.5 / 13.5 | 100 contributors |
| OpenSSF Scorecard: Contributors | met | 10 / 10 | project has 28 contributing companies or organizations |

### Issue & PR responsiveness — 77/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Issue resolution | partial | 36.8 / 42 | 88% of issues closed |
| PR acceptance | partial | 24.6 / 30 | 1386/1691 decided PRs merged |
| Newcomer PR acceptance | partial | 9.3 / 13 | 5/7 first-time contributors' PRs merged in 30d |
| OpenSSF Scorecard: Code-Review | partial | 6 / 15 | Found 13/30 approved changesets -- score normalized to 4 |

### Ownership & stewardship — 68/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ownership backing | met | 30 / 30 | organization-owned |
| Verified domain | not met | 0 / 20 | — |
| Owner reach | partial | 15.5 / 25 | 143 followers of simdjson |
| Track record | partial | 22.2 / 25 | 24 public repos, account ~6 yr old |

## Engineering Quality — 82/100 (Excellent)

Are baseline engineering and documentation practices in place? Weight: 19% of the overall index.

### Engineering practices — 70/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| CI workflows | met | 24 / 24 | 44 workflow(s) |
| Tests present | met | 24 / 24 | — |
| Linter config | not met | 0 / 16 | — |
| Pre-commit hooks | not met | 0 / 9.6 | — |
| .editorconfig | met | 6.4 / 6.4 | — |
| OpenSSF Scorecard: CI-Tests | partial | 16 / 20 | 24 out of 27 merged PRs checked by a CI test -- score normalized to 8 |

### Documentation — 100/100 (Exceptional)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 30 / 30 | — |
| Documentation directory | met | 25 / 25 | — |
| Documentation / homepage site | met | 15 / 15 | https://simdjson.org |
| Repository description | met | 10 / 10 | — |
| Topics | met | 10 / 10 | 20 topics |
| Wiki | met | 10 / 10 | — |

## Security — 34/100 (At Risk)

Are visible security and supply-chain practices strong, with no malicious dependency and no unresolved high-risk jurisdiction exposure? Weight: 16% of the overall index.

### Security posture — 18/100 (Critical)

Excluded from scoring (no data or not applicable): Packaging. Remaining weights renormalized. A dependency reported as a malicious package applies a 35% multiplier to Security posture and gives it a Critical ceiling of 19.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Binary-Artifacts | met | 7.5 / 7.5 | no binaries found in the repo |
| Branch-Protection | not met | 0 / 7.5 | branch protection not enabled on development/release branches |
| CI-Tests | partial | 2 / 2.5 | 24 out of 27 merged PRs checked by a CI test -- score normalized to 8 |
| CII-Best-Practices | not met | 0 / 2.5 | no effort to earn an OpenSSF best practices badge detected |
| Code-Review | partial | 3 / 7.5 | Found 13/30 approved changesets -- score normalized to 4 |
| Contributors | met | 2.5 / 2.5 | project has 28 contributing companies or organizations |
| Dangerous-Workflow | met | 10 / 10 | no dangerous workflow patterns detected |
| Dependency-Update-Tool | not met | 0 / 7.5 | no update tool detected |
| Fuzzing | met | 5 / 5 | project is fuzzed |
| License | met | 2.5 / 2.5 | license file detected |
| Maintained | met | 7.5 / 7.5 | 30 commit(s) and 20 issue activity found in the last 90 days -- score normalized to 10 |
| Packaging | excluded | 0 / 5 | packaging workflow not detected |
| Pinned-Dependencies | not met | 0 / 5 | dependency not pinned by hash detected -- score normalized to 0 |
| SAST | not met | 0 / 5 | SAST tool is not run on all commits -- score normalized to 0 |
| Security-Policy | met | 5 / 5 | security policy file detected |
| Signed-Releases | not met | 0 / 7.5 | Project has not signed or included provenance with any releases. |
| Token-Permissions | not met | 0 / 7.5 | detected GitHub workflow tokens with excessive permissions |
| Vulnerabilities | partial | 6.8 / 7.5 | 1 existing vulnerabilities detected |

### Dependency advisories — 100/100 (Exceptional)

Excluded from scoring (no data or not applicable): Indirect dependencies free of known advisories, No advisories left outstanding. Remaining weights renormalized. Matched 13 resolved dependencies against OSV. This repository publishes no package the index resolves, so the repository dependency graph was assessed instead. That graph mixes development and test pins with shipped dependencies, so only the declared runtime dependencies are scored; transitive findings are reported as context and excluded from the score. Reachability is not analyzed.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Direct dependencies free of known advisories | met | 35 / 35 | no direct dependency carries a known advisory |
| Indirect dependencies free of known advisories | excluded | 0 / 25 | transitive set not separable from development and test dependencies in this scope |
| No advisories left outstanding | excluded | 0 / 40 | no advisory carries a publication date |

### Malicious dependencies — 35/100 (Weak)

1 resolved dependency(ies) resolve to a version the registry still serves and the OpenSSF corpus reports as malicious. Direct and indirect are treated alike: an install-time payload runs at any depth in the graph. A report here concerns the package as published, not the maintainers of this repository, which may have resolved it unknowingly.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| No dependency reported as a malicious package | partial | 35 / 100 | 1 reported as malicious: fs 0.0.1-security |

### High-Risk Jurisdiction Exposure — 100/100 (Exceptional)

Only high-confidence self-published location evidence affects this multiplier. Ambiguous matches are review-only; country evidence is not proof of nationality, citizenship, legal registration, malicious intent, or sanctions status.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Policy exposure multiplier | met | 100 / 100 | no confirmed policy-scope location match |

## AI Readiness — 68/100 (Good)

How well is the repo equipped to be developed and maintained with AI coding agents? Carries a deliberately small weight: agent tooling is a real maintenance signal, but its absence must never gate the top of the scale (calibration saturates at raw 91, so 100/100 remains reachable with AI Readiness at zero).

### Agent context & guidance — 40/100 (Weak)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Agent instructions | not met | 0 / 45 | no CLAUDE.md / AGENTS.md / editor rules |
| Machine-readable docs (llms.txt) | not met | 0 / 15 | — |
| Legible commit history | met | 40 / 40 | 80 of 100 human commits state their intent (structured subject or explanatory body) |

### Verify loop (build / test / typecheck) — 65/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| One-command bootstrap | met | 18 / 18 | examples/quickstart/Makefile, scripts/transitions/Makefile |
| Automated tests | met | 22 / 22 | — |
| Lint / format config | not met | 0 / 11 | — |
| Static type checking | met | 11 / 11 | C++ (statically typed) |
| Reproducible environment | met | 10 / 10 | Dockerfile, lockfile |
| Demonstrated agent practice | partial | 4 / 10 | 2 of the last 100 commits agent-authored or agent-credited |
| Automated maintenance | not met | 0 / 8 | no automated dependency updates observed |
| OpenSSF Scorecard: Pinned-Dependencies | not met | 0 / 10 | dependency not pinned by hash detected -- score normalized to 0 |

### Code legibility for models — 99/100 (Exceptional)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Type-checkable code | met | 45 / 45 | C++ (statically typed) |
| Manageable file sizes | partial | 54 / 55 | 10/566 source files over 60KB |

### Machine-readable interfaces — 100/100 (Exceptional)

Excluded from scoring (no data or not applicable): API schema (OpenAPI/GraphQL/proto), MCP server. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| API schema (OpenAPI/GraphQL/proto) | excluded | 0 / 40 | not applicable to this kind of software |
| MCP server | excluded | 0 / 20 | not applicable to this kind of software |
| Runnable examples | met | 40 / 40 | examples |

## Collection warnings

- Star history unavailable: GitHub GraphQL error: Resource not accessible by personal access token
- Could not fetch npm package 'generatelargejson' from its registry

## What this report is

inspect.software measures public repositories against a single published, versioned methodology and reports the result as a 1–100 health index. Findings are signals derived from what is visible in public repository data — they are not a security audit, a warranty, or an endorsement, and no result depends on payment.

- Methodology, formulas and weights: https://inspect.software/methodology.md
- What a result does and does not claim: https://inspect.software/wiki/signals-not-warranties.md
- Rating bands: https://inspect.software/wiki/scoring-bands.md
- Corrections: https://inspect.software/contact.md
- Index of all documents: https://inspect.software/llms.txt