Open Sourcing

Open-Sourcing a Repository

Prepare a repository for public release so that an outsider with no prior

context can build, use, and contribute to it — and so that nothing sensitive

ships with it. Work through the steps in order; the secrets audit comes first

because its outcome (keeping vs. recreating the repository) affects

everything after it.

When to Use

• Making a private repository public
• Auditing an existing public repository for release quality ("make it

official")

• Choosing a license for a project
• Setting up packaging, versioning, or release automation ahead of a public

launch

When NOT to Use

• Routine development on an already-released project (no release event)
• Auditing third-party code for vulnerabilities (use a security-review skill)
• Publishing a package from a repository that will stay private — only the

release-management steps apply; skip the rest

Workflow

Step 1: Detect the organization profile

bash {baseDir}/scripts/detect_org.sh

The script inspects git remotes and recent committer emails, and prints a

profile name. If it prints trailofbits, read

references/trailofbits.md now and apply its

license policy, publishing accounts, and process notes throughout the

remaining steps. If it prints generic, proceed with the generic guidance

alone. If the user says the detection is wrong, trust the user.

Step 2: Audit for secrets — before anything else

A repository that has ever contained secrets (API keys, credentials,

client data) should not be flipped public. History rewriting is error-prone

and does not reach forks, caches, or CI artifacts. The reliable fix is a

fresh repository: copy the current tree over, commit, and archive the old

repository privately.

• Ask whether the project ever handled secrets or client-confidential

material. For a security consultancy's tooling, also ask whether test

fixtures or example data came from client engagements.

• Scan the full history with a dedicated tool if available —

gitleaks git . or trufflehog git file://. — rather than eyeballing.

• Check beyond the git tree: GitHub Actions logs and artifacts, old

releases, issue and PR history, and the repository wiki all become public

with the repository.

• After going public, enable GitHub secret scanning and push protection in

the repository settings.

Reject these rationalizations — this is the one step that cannot be fixed

after publication:

• *"The key was revoked, so the history is fine."* Revoked credentials still

leak infrastructure names, internal URLs, and patterns attackers use for

targeting.

• *"We'll rewrite history with git-filter-repo."* Rewrites miss forks,

clones, caches, and CI artifacts; the fresh-repository approach does not.

• *"It's only test data."* Fixtures derived from client engagements or

production systems are confidential regardless of how they are labeled.

Step 3: Run the readiness check

bash {baseDir}/scripts/check_readiness.sh

The script prints a checklist of presence indicators (README, LICENSE,

CONTRIBUTING, SECURITY.md, CI, tests, semver tags, ...) and warns about

tracked files that commonly contain secrets. Treat unchecked items as

discussion prompts, not hard failures — a research prototype does not need

everything a flagship library needs. Walk through the gaps with the user and

fix the ones that matter for this project.

Step 4: Documentation

The README is the project's front door. Confirm it explains:

• What the project is and what problem it solves (first paragraph)
• How to install it — package manager, container image, or build from

source; a fresh-clone build must work using only what is in the repository

• How to use it — at least one concrete, copy-pasteable example
• How to contribute — inline or via CONTRIBUTING.md
• The license — a short section naming it

Also add:

• SECURITY.md with vulnerability-reporting instructions (a contact

address or GitHub private vulnerability reporting). For security tooling

this is table stakes.

• API documentation, built and hosted (GitHub Pages via CI is the usual

route), linked from the README and the repository website field. See the

language references below for per-ecosystem doc tooling.

• A code of conduct if the project expects outside contributors.

Step 5: Licensing

No license means not open source, regardless of visibility. Read

references/licensing.md for selection criteria and

mechanics. The short version:

• Apply the organization's policy if one was detected in Step 1.
• Otherwise: Apache 2.0 as the permissive default, AGPLv3 when private

modification by competitors is a real concern, Creative Commons for

non-code artifacts.

• Add the LICENSE file, set SPDX identifiers in package metadata, state

the license in the README, and verify all three agree.

Step 6: Tests and CI

• Confirm the test suite exists and passes; a public repository with a

failing default branch signals abandonment.

• Ensure CI runs the tests on every PR, across the supported

language-version and platform matrix.

• Enforce formatting and linting in CI (per-language tooling in the

references below), so style debates never reach review.

• Respect existing tooling. Do not replace a working formatter, linter,

or type checker as part of open-sourcing. If it lags the current

generation (the language references name the current tools), warn the

maintainer and let them decide; only when a category is missing entirely —

no type checker, no formatter — add the current default.

• Consider a coverage gate that fails CI when coverage drops.
• Harden the workflows themselves before they become public attack surface:
• Pin third-party actions to full commit SHAs; enable Dependabot for

github-actions so pins stay current.

• Set least-privilege permissions: blocks (start from permissions: {}).
• Audit with zizmor .github/workflows/ and lint with actionlint.

Step 7: Repository settings

• Branch protection on the default branch: no force pushes, PRs

required. Prefer rulesets for new repositories; classic branch protection

remains supported.

• Merge protection: required status checks so PRs cannot merge with

failing tests.

• Dependabot or Renovate for dependency and Actions updates. Group

updates to cut PR noise, and set a cooldown window (e.g., 7 days) so

freshly published — and occasionally hijacked — versions age before

adoption.

• .editorconfig so contributors' editors agree on whitespace basics.
• Labels: create them as soon as more than one issue or PR needs one;

prefixes for facets scale well (C: component, P: platform). See

blight's labels for a

worked example.

Step 8: Releases and versioning

• Tag every release vX.Y.Z, following semver; use

-rc.N / -pre.N suffixes for release candidates and prereleases.

• Make releases CI-driven: pushing a tag (or publishing a GitHub Release)

triggers build, packaging, and upload with no manual steps. A release

should be git tag vX.Y.Z && git push origin vX.Y.Z.

• Publish packages under an organization-owned account, not a personal one,

and use trusted publishing (OIDC) instead of long-lived tokens wherever

the index supports it.

Step 9: Language-specific practices

Identify the project's languages from its marker files and read the matching

reference for packaging, publishing, and quality tooling:

| Marker file | Reference |

|-------------|-----------|

| pyproject.toml, setup.py | references/python.md — defers to the modern-python skill for tooling |

| CMakeLists.txt, Makefile (C/C++) | references/c-cpp.md |

| Cargo.toml | references/rust.md |

| go.mod | references/go.md |

| package.json | references/javascript.md |

| Gemfile, *.gemspec | references/ruby.md |

For other ecosystems, apply the cross-cutting principles: reproducible

builds from a fresh clone, CI-driven releases, trusted publishing or

organization-owned accounts, and license metadata in the package manifest.

Final Review

Before the visibility switch is flipped, verify from an outsider's

perspective:

• Clone into a clean directory and follow the README's build instructions

verbatim — do they work with no tribal knowledge?

• Re-run {baseDir}/scripts/check_readiness.sh and confirm the remaining

gaps are deliberate choices, stated to the user.

• Confirm the secrets audit (Step 2) actually happened; it is the one step

that cannot be fixed after publication.

Making the repository public is then a repository-settings change. Pair the

release with an announcement where the organization has a process for one.

Additional Resources

Reference Files

• references/licensing.md — license selection

criteria, SPDX metadata, forks and relicensing

• references/trailofbits.md — Trail of Bits

policy overlay (loaded only when detected in Step 1)

• references/python.md,

references/c-cpp.md,

references/rust.md,

references/go.md,

references/javascript.md,

references/ruby.md — per-language packaging,

publishing, and quality tooling

Scripts

• scripts/detect_org.sh — prints the organization profile

(trailofbits or generic) from git remotes and committer emails

• scripts/check_readiness.sh — prints presence indicators for

release-readiness files and flags tracked files that commonly hold secrets