QUICK ANSWER
What should a changelog template include?
A changelog template should keep an Unreleased section above versions ordered newest first. Each version needs a SemVer-compatible identifier when that policy applies, an ISO date, categorized entries, stable entry IDs, accountable references, and a compare link to the prior version. The record should explicitly remain separate from release notes, a product changelog, roadmap, change request, release or deployment plan, incident record, advisory, and proof that work shipped.
A project changelog is the maintained history between versions: a standing Unreleased section, stable entries, dated releases, category rules, references, and compare links. It helps contributors understand how a repository changed without turning every version into an audience-facing announcement.
The downloadable pack includes an original Markdown template, completed fictional Markdown and JSON examples, a closed Draft 2020-12 schema, and a dependency-free validator. It owns continuous project history only. Release notes, the Playcode product changelog, roadmap commitments, change requests, release or deployment plans, and incident or advisory records stay separate.
Maintain one history from Unreleased to versioned entries
The template treats the changelog as a durable repository document. A short entry moves through a controlled version boundary without being rewritten as release marketing or proof of deployment.
Name the history owner and adjacent records
Assign one role to maintain repository history, then state what the changelog does not own. Audience-facing release notes, product updates, future commitments, approvals, plans, incidents, and advisories need their own accountable records.
Sources: [keep-a-changelog-1-1], [github-releases]
Collect candidate entries under Unreleased
Give every entry a stable ID, one allowed category, a concise repository-history summary, and at least one issue, pull-request, or documentation reference. This pack deliberately adopts Keep a Changelog’s Unreleased convention; Common Changelog omits that section, so do not present one format as universal. Unreleased may be empty after a cut, but a dated release must never be empty.
Sources: [keep-a-changelog-1-1], [common-changelog]
Use a small controlled category set
This pack deliberately uses Keep a Changelog’s Added, Changed, Deprecated, Removed, Fixed, and Security set. Common Changelog uses a narrower category set. Pick and document one policy, do not create near-duplicate labels, and route sensitive advisory detail to the security owner.
Sources: [keep-a-changelog-1-1], [common-changelog]
Cut a dated version without erasing prior history
Move reviewed Unreleased entries into a new version, order versions and ISO dates newest first, and connect adjacent versions with compare references. Use Semantic Versioning only when the project has declared the public compatibility contract it requires.
Sources: [semver-2], [keep-a-changelog-1-1], [common-changelog]
Validate shape, references, safety, and boundaries
Check the closed JSON shape, version and date order, unique IDs, allowed categories, nonempty releases, resolved references, compare-link roles, selected secret and personal-data patterns, and ownership flags. A validator pass is consistency evidence, not proof that a change shipped.
Sources: [json-schema-2020-12], [github-releases]
What this changelog template owns
Use the template for continuous project or repository history that contributors can scan and validate over time. Hand every adjacent decision to its separate owner.
Included
- One Unreleased section, newest-first dated releases, stable entry IDs, controlled categories, issue or pull-request references, and adjacent-version compare links
- Original Markdown template, a completed fictional Markdown and JSON example, a closed Draft 2020-12 schema, dependency-free validator tests, README, and deterministic ZIP build
- Checks for strict SemVer, calendar-valid ISO dates and date order, duplicate IDs and versions, invalid categories, empty releases, unresolved or misclassified references, compare links, selected secrets or personal data, and explicit ownership boundaries
Not included
- Audience-facing release notes for one shipped version, compatibility instructions, migration communication, launch announcement, or customer action
- The Playcode product changelog at /changelog, another product update feed, or an automatic publication pipeline
- Roadmap, feature request, change request, issue prioritization, implementation ticket, release plan, deployment plan, approval, or launch checklist
- Incident timeline, root-cause analysis, vulnerability or security advisory, private evidence, credentials, personal data, or confidential customer records
- Proof that an entry shipped, a tag is authentic, a compare result is complete, a version is compatible, or publication is safe
DOWNLOADABLE RESOURCE
Download the changelog template pack
The ZIP contains the editable Markdown template, a completed fictional Markdown and JSON history, the closed schema, and the exact dependency-free validator and tests used to check order, IDs, categories, references, compare links, selected unsafe data, and owner boundaries.
Changelog template pack
A continuous project-history record with Unreleased and version sections, stable entry IDs, controlled categories, accountable references, and compare links.
Format: Markdown, JSON, JSON Schema, and dependency-free Node.js validator/tests in one ZIP
Locally reproduced August 1, 2026. SHA-256: d082260aeda27388a2ce362a80c6d72cf0ca61a4ccda7415f7019b7982f89b58
Included
- Original CHANGELOG.template.md starter and a completed fictional Cedar Finch Archive Markdown example using reserved .example.test references
- Completed JSON example and closed Draft 2020-12 schema for Unreleased, releases, dates, entries, categories, references, compare links, and boundaries
- Forty-eight dependency-free tests plus exact eight-file allowlist, extraction parity, clean rebuild, two-build determinism, and locked SHA-256 checks in the page-local verification suite
Verification boundary
The exact eight-file allowlist was reproduced twice, extracted, byte-compared across source, public, and archive copies, and tested locally. This verifies the pack bytes and internal contracts, not whether real repository history is complete, work shipped, compare results are authentic, or publishing is safe.
Three changelog shapes for continuous history
Keep the same owner and record model, then adjust entry detail and version policy to the repository rather than turning the changelog into a different document type.
Open-source library history
Use when: Maintainers need a durable record of public API additions, fixes, deprecations, removals, and security-classified entries across tagged versions.
Use Unreleased for reviewed candidate entries, stable IDs and references for traceability, SemVer for a declared public API, and compare links between adjacent versions.
Structure
- Unreleased entries grouped by the controlled categories with issue, pull-request, or documentation references
- Newest-first SemVer releases with ISO dates and adjacent compare links, while advisory detail remains separately owned
Watch for: A changelog entry does not prove package publication, downstream compatibility, migration completion, disclosure safety, or support for every consumer.
Sources: [keep-a-changelog-1-1], [semver-2]
Internal service repository
Use when: An engineering team needs searchable implementation history even when customer-facing communication happens through another release process.
Keep concise repository facts, owner-reviewed references, stable IDs, dated versions, and compare links; send operator actions, approvals, deployment steps, and incidents to their dedicated records.
Structure
- Unreleased repository changes tied to internal issue and review references without credentials or personal data
- Dated version history that preserves previous entries and keeps release, deployment, incident, and advisory decisions outside the document
Watch for: An internal changelog is not a deployment ledger, approval record, incident timeline, evidence archive, or guarantee that every environment runs the same version.
Sources: [common-changelog], [github-releases]
Small app or website project history
Use when: A small team wants one readable history file without adopting a large release-management system or mixing product announcements into repository notes.
Use the minimum useful fields: Unreleased, dated versions, controlled categories, stable entries, references, and compare links. Add detail only when it changes a reader decision.
Structure
- Short entries that name the changed behavior and accountable source without promotional claims or future promises
- A version and date order that is validated mechanically while the owner verifies the actual repository state
Watch for: A small format still needs review for truth, privacy, security, accessibility, legal duties, and whether a separate release note or customer communication is required.
Sources: [json-schema-2020-12], [common-changelog]
Decide what belongs in the changelog
Use the changelog only when the entry is a concise, attributable part of continuous project history. Route decisions, promises, operations, and sensitive records elsewhere.
The item describes a completed repository change with an accountable reference
Choose: Add a stable entry under Unreleased, choose one controlled category, and retain the issue, pull-request, or documentation reference when cutting the next version.
Tradeoff: The entry stays concise and traceable, but audience impact and migration detail may still need separate release notes.
The item asks for work, predicts a date, requests approval, or describes deployment steps
Choose: Keep it in the roadmap, request, plan, issue, approval, or deployment record until a repository-history fact actually exists.
Tradeoff: The changelog contains less planning context, but its history no longer implies that proposed or merely deployed work belongs to a released version.
Readers need audience impact, actions, compatibility, migration, or known-limit guidance for one version
Choose: Create separately owned release notes and link back to the relevant version history instead of expanding the changelog into a launch announcement.
Tradeoff: Two records must stay aligned, but contributors get stable history while the audience gets decision-ready communication.
The entry contains incident detail, exploit information, secrets, personal data, or private evidence
Choose: Remove the protected material and route the record through the accountable incident, security, privacy, legal, or customer-communication process.
Tradeoff: The public or shared changelog shows less detail, preventing a history file from becoming an unsafe disclosure channel.
USE THE VALIDATED RESOURCE
Download the changelog pack
Start with the original Markdown template, fictional example, closed schema, and dependency-free validator. Replace every example field with reviewed repository history.
Download the changelog packThe pack validates structure and boundaries. It does not prove that any real change shipped.
Download the release notes templateUse release notes when one shipped version needs audience impact, required actions, compatibility, migration, known limits, and public-safe evidence.
Limits to review before publishing a changelog
A structured changelog can expose inconsistent history and selected unsafe patterns. It cannot authenticate the repository, execute software, or replace accountable review.
- The pack is continuous project history, not release notes, the Playcode product changelog, a roadmap, change request, implementation or deployment plan, approval, incident record, or security advisory.
- The validator checks closed shape, strict SemVer, calendar-valid ISO dates and date order, stable IDs, categories, nonempty releases, references, compare-link roles, selected unsafe strings, and owner boundaries. It does not prove that a change shipped or a URL is truthful.
- Cedar Finch Archive, its entries, versions, dates, and reserved-host references are fictional examples, not performance, compatibility, reliability, delivery, or adoption claims.
- Semantic Versioning applies only when a public API is declared under that contract. CalVer, date versions, or another policy require a separately adapted model and validator.
- Selected secret and personal-data patterns are guardrails, not comprehensive secret scanning, privacy review, security review, incident handling, or coordinated disclosure.
- An accountable owner must verify repository facts, disclosure scope, compatibility, accessibility, localization, privacy, security, legal, and customer-communication obligations before publication.
Primary sources used for the changelog boundary
These current specifications and official guides support the Unreleased and version model, category choices, change-format principles, version semantics, release boundary, and closed schema. The templates and cross-field validation rules are original Playcode editorial work.
[keep-a-changelog-1-1] Keep a Changelog:Keep a Changelog 1.1.0
Checked August 1, 2026. Supports: A human-curated changelog with an Unreleased section, versions and dates, reverse chronology, links, and Added, Changed, Deprecated, Removed, Fixed, and Security categories.
[common-changelog] Common Changelog:Common Changelog specification
Checked August 1, 2026. Supports: A predictable changelog format for project changes, version sections, dates, entry grouping, and references. It does not prove repository or deployment state.
[semver-2] Semantic Versioning:Semantic Versioning 2.0.0
Checked August 1, 2026. Supports: Version ordering and major, minor, patch, prerelease, build-metadata, public-API, and immutability semantics when a project adopts SemVer.
[github-releases] GitHub Docs:About releases
Checked August 1, 2026. Supports: GitHub releases as packaged repository iterations based on tags with release notes and assets, establishing the adjacent release surface this changelog does not replace.
[json-schema-2020-12] JSON Schema:JSON Schema Draft 2020-12
Checked August 1, 2026. Supports: The declared schema dialect and closed machine-readable record shape. Cross-record ordering, reference, safety, and ownership rules remain validator responsibilities.
Changelog template questions
What is a changelog template?
It is a reusable structure for continuous project history. This template keeps an Unreleased section above newest-first versions, with ISO dates, controlled categories, stable entry IDs, references, and compare links. It does not replace release notes, a product changelog, roadmap, request, plan, incident record, or advisory.
What is the difference between a changelog and release notes?
A changelog is continuous repository or project history across versions. Release notes explain one shipped version to a specific audience, including impact, required actions, compatibility, migration, known limits, and public-safe evidence. Keep both when contributors and external readers need different levels of detail.
Should a changelog have an Unreleased section?
Yes when you need one visible holding area for reviewed candidate entries. It may be empty immediately after a version cut. A dated release should not be empty, and an Unreleased item must not be treated as a roadmap promise or proof that work will ship.
Which changelog categories should I use?
This pack adopts Keep a Changelog’s Added, Changed, Deprecated, Removed, Fixed, and Security categories. Common Changelog uses a narrower set, so there is no single universal rule. Pick one documented policy, keep validation aligned, and put advisory or exploit detail in the accountable security process.
Does every changelog need Semantic Versioning?
No. SemVer is appropriate when a project declares a public API and follows that compatibility contract. The bundled validator models SemVer 2.0.0. A CalVer, date-version, or custom policy needs an adapted schema, ordering rule, examples, and review boundary.
Does a validated changelog prove that a change shipped?
No. Validation checks the record shape, order, IDs, categories, references, compare-link roles, selected unsafe strings, and ownership flags. An accountable owner must still verify repository tags, source references, deployment state, compatibility, and disclosure safety.
Where should a changelog live?
For a code repository, a root CHANGELOG.md is easy to discover, review, and version with the project. Keep the machine-readable companion and validator beside the maintained source when automation needs them. Do not confuse that file with Playcode product updates at /changelog.
TURN REVIEWED HISTORY INTO EXPLICIT REQUIREMENTS
Build the next reviewed change
Describe the users, records, states, interactions, constraints, tests, exclusions, and approval boundary for the next app. Keep changelog history as context rather than an implementation command.
Build the next reviewed changeThis informational article is credit-ineligible. The linked product page follows its own current eligibility rules.