# trezor/trezor-mcu — health index 17/100 (Critical)

> Inspection of the public repository trezor/trezor-mcu by inspect.software. It holds a health index of 17 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/trezor/trezor-mcu
- Report page: https://inspect.software/software/trezor/trezor-mcu
- Full JSON report: https://inspect.software/api/repositories/trezor/trezor-mcu/report
- Badge: https://raw.githubusercontent.com/inspect-software/badges/main/v1/t/trezor/trezor-mcu.svg
- Inspected: 2026-07-23
- Methodology: metrics 1.13.0, report schema 0.27.0 (https://inspect.software/methodology.md)

## Category summary

| Category | Weight | Index | Band |
|---|---|---|---|
| Vitality | 22% | 17/100 | Critical |
| Community & Adoption | 18% | 67/100 | Moderate |
| Sustainability & Governance | 24% | 62/100 | Moderate |
| Engineering Quality | 20% | 27/100 | Critical |
| Security | 16% | 41/100 | At risk |
| AI Readiness | not counted | 49/100 | At risk |

Abandonment Policy applies a 40% multiplier to weighted overall health and gives it a ceiling of 29.

## Repository facts

| Field | Value |
|---|---|
| Description | :lock: Don't use this repo, use the new monorepo instead: |
| Homepage | https://github.com/trezor/trezor-firmware |
| Primary language | C |
| License | LGPL-3.0 |
| Stars | 312 |
| Forks | 249 |
| Created | 2012-11-16 |
| Last push | 2019-04-10 |
| Latest release | v1.8.0 |
| Commits (last year) | 0 |
| Bus factor | 1 |
| Topics | bitcoin, trezor, hardware, wallet, open-source, embedded, arm |
| Archived | yes — the repository is no longer maintained on GitHub |

## Vitality — 17/100 (Critical)

Is the project alive — is code being written and are releases shipping? Weight: 22% of the overall index.

### Development activity — 1/100 (Critical)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Push recency | not met | 0 / 36 | last push 2661 days ago |
| Commit cadence | not met | 0 / 36 | 0/52 weeks with commits |
| Commit volume | not met | 0 / 18 | 0 commits in the last year |
| OpenSSF Scorecard: Maintained | not met | 0 / 10 | project is archived |

### Release discipline — 40/100 (At risk)

Excluded from scoring (no data or not applicable): OpenSSF Scorecard: Signed-Releases. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ships releases | partial | 16.2 / 27 | 26 version tags (no GitHub releases) |
| Release recency | not met | 0 / 36 | latest release 2705 days ago |
| Release cadence | partial | 19.8 / 27 | a release every ~61.9 days |
| OpenSSF Scorecard: Signed-Releases | excluded | 0 / 10 | no releases found |

### Abandonment — 40/100 (At risk)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Project is still maintained | partial | 40 / 100 | the repository is archived on GitHub |

## Community & Adoption — 67/100 (Moderate)

Does the project have users, downloads, attention, and a welcoming setup for contributors? Weight: 18% of the overall index.

### Popularity & adoption — 64/100 (Moderate)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Stars | partial | 40.4 / 60 | 312 stars |
| Forks | partial | 20 / 25 | 249 forks |
| Watchers | partial | 3.9 / 15 | 6 watchers |

### Community health — 70/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 22.5 / 22.5 | — |
| License | met | 22.5 / 22.5 | recognized license (LGPL-3.0) |
| CONTRIBUTING guide | met | 18 / 18 | — |
| Code of conduct | not met | 0 / 13.5 | — |
| Issue template | not met | 0 / 7.2 | — |
| PR template | not met | 0 / 6.3 | — |

## Sustainability & Governance — 62/100 (Moderate)

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep? Weight: 24% of the overall index.

### Maintainer resilience (bus factor) — 41/100 (At risk)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Bus factor | partial | 9 / 54 | 1 contributor(s) cover half of all commits |
| Commit distribution | partial | 8.4 / 22.5 | top contributor authored 63% of commits |
| Contributor breadth | met | 13.5 / 13.5 | 33 contributors |
| OpenSSF Scorecard: Contributors | met | 10 / 10 | project has 25 contributing companies or organizations |

### Issue & PR responsiveness — 73/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Issue resolution | met | 46.8 / 46.8 | 100% of issues closed |
| PR acceptance | partial | 26.4 / 38.2 | 177/256 decided PRs merged |
| OpenSSF Scorecard: Code-Review | not met | 0 / 15 | Found 2/25 approved changesets -- score normalized to 0 |

### Ownership & stewardship — 77/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ownership backing | met | 30 / 30 | organization-owned |
| Verified domain | not met | 0 / 20 | — |
| Owner reach | partial | 22.3 / 25 | 1,245 followers of trezor |
| Track record | met | 25 / 25 | 67 public repos, account ~13 yr old |

## Engineering Quality — 27/100 (Critical)

Are baseline engineering and documentation practices in place? Weight: 20% of the overall index.

### Engineering practices — 1/100 (Critical)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| CI workflows | not met | 0 / 24 | — |
| Tests present | not met | 0 / 24 | — |
| Linter config | not met | 0 / 16 | — |
| Pre-commit hooks | not met | 0 / 9.6 | — |
| .editorconfig | not met | 0 / 6.4 | — |
| OpenSSF Scorecard: CI-Tests | not met | 0 / 20 | 0 out of 3 merged PRs checked by a CI test -- score normalized to 0 |

### Documentation — 65/100 (Moderate)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 30 / 30 | — |
| Documentation directory | not met | 0 / 25 | — |
| Documentation / homepage site | met | 15 / 15 | https://github.com/trezor/trezor-firmware |
| Repository description | met | 10 / 10 | — |
| Topics | met | 10 / 10 | 7 topics |
| Wiki | not met | 0 / 10 | — |

## Security — 41/100 (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 — 26/100 (Critical)

Excluded from scoring (no data or not applicable): Branch-Protection, Dangerous-Workflow, Packaging, Signed-Releases, Token-Permissions. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Binary-Artifacts | met | 7.5 / 7.5 | no binaries found in the repo |
| Branch-Protection | excluded | 0 / 7.5 | internal error: error during branchesHandler.setup: internal error: some github tokens can't read classic branch protection rules: https://github.com/ossf/scorecard-action/blob/main/docs/authentication/fine-grained-auth-token.md |
| CI-Tests | not met | 0 / 2.5 | 0 out of 3 merged PRs checked by a CI test -- score normalized to 0 |
| CII-Best-Practices | not met | 0 / 2.5 | no effort to earn an OpenSSF best practices badge detected |
| Code-Review | not met | 0 / 7.5 | Found 2/25 approved changesets -- score normalized to 0 |
| Contributors | met | 2.5 / 2.5 | project has 25 contributing companies or organizations |
| Dangerous-Workflow | excluded | 0 / 10 | no workflows found |
| Dependency-Update-Tool | not met | 0 / 7.5 | no update tool detected |
| Fuzzing | not met | 0 / 5 | project is not fuzzed |
| License | met | 2.5 / 2.5 | license file detected |
| Maintained | not met | 0 / 7.5 | project is archived |
| 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 | excluded | 0 / 7.5 | no releases found |
| Token-Permissions | excluded | 0 / 7.5 | No tokens found |
| Vulnerabilities | not met | 0 / 7.5 | 35 existing vulnerabilities detected |

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

Excluded from scoring (no data or not applicable): Indirect dependencies free of known advisories, No advisories left outstanding. Remaining weights renormalized. Matched 25 resolved dependencies against OSV; 1 could not be assessed (no resolved version, an unsupported ecosystem, or beyond the reported package list). 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 — 100/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| No dependency reported as a malicious package | met | 100 / 100 | no dependency is reported as a malicious package |

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

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 — 49/100 (At risk)

How well is the repo equipped to be developed and maintained with AI coding agents? An independent, experimental badge — weight 0.0, so it is surfaced on its own and does not affect the overall health score.

### Agent context & guidance — 40/100 (At risk)

| 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 | 76 of 100 human commits state their intent (structured subject or explanatory body) |

### Verify loop (build / test / typecheck) — 39/100 (At risk)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| One-command bootstrap | met | 18 / 18 | Makefile, bootloader/Makefile, demo/Makefile, emulator/Makefile, firmware/Makefile, firmware/protob/Makefile, gen/Makefile |
| Automated tests | not met | 0 / 22 | — |
| Lint / format config | not met | 0 / 11 | — |
| Static type checking | met | 11 / 11 | C (statically typed) |
| Reproducible environment | met | 10 / 10 | Dockerfile, Nix, lockfile |
| Demonstrated agent practice | not met | 0 / 10 | no agent-authored commits among the last 100 |
| 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 — 100/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Type-checkable code | met | 45 / 45 | C (statically typed) |
| Manageable file sizes | met | 55 / 55 | 0/129 source files over 60KB |

### Machine-readable interfaces — 40/100 (At risk)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| API schema (OpenAPI/GraphQL/proto) | met | 40 / 40 | firmware/protob/messages-bitcoin.proto, firmware/protob/messages-common.proto, firmware/protob/messages-crypto.proto, firmware/protob/messages-debug.proto, firmware/protob/messages-ethereum.proto, firmware/protob/messages-lisk.proto, firmware/protob/messages-management.proto, firmware/protob/messages-nem.proto, firmware/protob/messages-stellar.proto, firmware/protob/messages.proto |
| MCP server | not met | 0 / 20 | — |
| Runnable examples | not met | 0 / 40 | — |

## Collection warnings

- Star history unavailable: GitHub GraphQL error: Resource not accessible by personal access token

## 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