---
title: Changelog
description: Cryo's changelog, rendered from CHANGELOG.md, with links to the versioning and support policies.
canonical: https://tech-pw.github.io/cryo/changelog/
updated: 2026-10-26
---

# Changelog

What changed in Cryo, generated from CHANGELOG.md at build time. Releases are tagged on GitHub; the version in the header is the latest tag.

Versions and support

Cryo is pre-1.0. The latest release is [v0.1.5](https://github.com/tech-pw/cryo/releases/tag/v0.1.5), and fixes go to the newest release line only; older tags aren't patched. How version numbers move is in [docs/VERSIONING.md](https://github.com/tech-pw/cryo/blob/main/docs/VERSIONING.md); what support covers is in [docs/SUPPORT_POLICY.md](https://github.com/tech-pw/cryo/blob/main/docs/SUPPORT_POLICY.md). All tags are on the [tags page](https://github.com/tech-pw/cryo/tags).

The `v0.1.x` tags were cut before the changelog had per-release sections, so their changes are still listed under Unreleased. Compare two tags on GitHub, for example [v0.1.4...v0.1.5](https://github.com/tech-pw/cryo/compare/v0.1.4...v0.1.5), to see exactly what shipped between them.

All notable changes to Cryo will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased](https://github.com/tech-pw/cryo/blob/main/CHANGELOG.md)

### Added

- Public chart README, NOTES, and a permissive values schema. Issue forms, CodeQL, labeler, and zizmor workflows. Contributor install no longer pulls the notebook `requirements.txt`.
- Open-source license metadata: `LICENSE` (Apache-2.0) at repo root, README license badge corrected from the `TBD` to Apache-2.0.
- `SECURITY.md` with GitHub Security Advisory routing and supported-versions table.
- `CODE_OF_CONDUCT.md` (Contributor Covenant 2.1).
- `.github/ISSUE_TEMPLATE/` (bug, feature) and `.github/PULL_REQUEST_TEMPLATE.md`.
- Initial `CHANGELOG.md`.
- Docs site: the header shows the latest release tag (`version` in `site/_src/site.json`), and new Changelog (rendered from this file) and Contributing pages.

### Security

- Failed password and Google sign-ins are throttled per account (5 in 15 minutes) and per client IP (20), using Redis so the limit holds across replicas. Locked attempts get `429` with `Retry-After`, and the sign-in page says how long to wait. Each failure is audited as `auth.login_failed` (admin-only `GET /api/v1/auth/audit`) and counted in `cryo_auth_login_failures_total`. `/docs`, `/redoc` and `/openapi.json` are off by default in `prod` (`CRYO_API_DOCS_ENABLED`). `CRYO_METRICS_BEARER_TOKEN` protects the scraper `/metrics`. See the operator guide (#262).

### Changed

- Docs site homepage: "Compact first, then clean up" is replaced by a scroll-driven story of one 1 TB table. It decays for 30 days, then goes through each operation in order while a pinned S3 bill shows what each step costs or saves ($110.72 to $23.53 a month in the example). Prices are S3 Standard us-east-1, and the expiry and orphan windows match the planner's defaults. The table is drawn as the brand's ice core sample and changes with each step: grains packing into blocks, old layers lifted into a tray, orphans swept into a pile. Cryo's mark narrates and fuses its cubes on `optimize`. Each chapter adds a plain-language analogy and a sourced cost that isn't on the bill (S3 503 throttling, request latency, Trino join order, GDPR deletes). It ends on a printed receipt and a "tables like this in your lake" estimator. A mood layer makes cost felt: the bill, its face, Cryo's mascot, the meters and the timeline rail go from green and smiling to red and crying as the bill climbs, and each step opens with a before-and-after scorecard.
- `LICENSE` and `deploy/helm/cryo/LICENSE` are now the verbatim Apache License 2.0 text. The previous copies had reworded clauses, so GitHub could not identify the license.
- GitHub (`tech-pw/cryo`) is now the only source of truth. The GitLab-to-GitHub mirror sync (`scripts/sync_oss_mirror.sh`, its exclude list, the `.gitlab-ci.yml` sync job and `docs/OSS_MIRROR.md`) is removed, so pull requests merged here are no longer overwritten.
- GitHub CI installs Python dependencies from `uv.lock` (the same lock the image ships) instead of resolving the newest releases on every run, builds `cryo-engine-go` for the scanner parity tests, and skips CodeQL and the Pages deploy while the repository is private. Lint, mypy, clippy, Rust and frontend tests that had drifted are fixed.
- New Cryo mark: small ice cubes fusing into one solid cube, replacing the faceted-iceberg mark, which was too close to the Apache Iceberg logo. Updated in `docs/brand/logo/` (with dark and one-colour variants), the docs site header, homepage animation, video poster and favicon, the web app's `CryoMark` and favicon, and the docs-site screenshots. See `docs/brand/CRYO_BRAND_GUIDE.md` §6. The homepage film still shows the old mark and needs a re-render from its source.
- `README.md` rewritten around images: hero banner, maintenance flow, product screenshots and architecture, each with light and dark versions. The long comparison, features and research sections are now collapsible. Images live in `docs/img/` and are rebuilt by `scripts/readme_images.mjs`. Removed a dead link to `docs/premortem.md`.
- Docs site homepage: the maintenance animation now follows one partition through five steps (scan, plan, admit, rewrite, receipt) with a live readout for each, before/after file stats, and a clickable step strip with pause and replay. Rebuilt as responsive HTML (`site/_src/includes/maintenance-flow.html`) instead of separate wide and compact SVGs.
- `site/scripts/preview.mjs` no longer crashes on request paths starting with `//` or on malformed percent-escapes.
- `README.md`: four explainer diagrams. What decays in an Iceberg table and which operation fixes each; how a table earns its A–F grade; how the planner chunks partitions under a GB budget, with the Trino and Spark SQL it renders; and how the governor admits a job into a free engine slot. "How it works" now walks scan → plan → admit → rewrite and record.
- `README.md`: license section now links to `LICENSE` instead of "TBD".
- Spark maintenance lanes run `local[N,3]` (task retries), cap the long-lived driver's status store, bulk-delete 1,000 S3 keys per request, retry throttled S3 calls 32 times, and may schedule on spot capacity with on-demand fallback (`maintenance.laneCapacityTypes`). Batch optimize rewrites only files under the scanner's small-file threshold and no longer splits files up to 10× target, orders rewrite groups `files-desc`, and `convert_deletes` removes the delete files it leaves dangling. See `docs/SPARK_ENGINE_OPTIMIZATION_2026-09-25.md`.

### Fixed

- The web UI's nginx now sends `Content-Security-Policy` (with `frame-ancestors 'none'`), `X-Frame-Options: DENY`, `X-Content-Type-Options: nosniff` and `Referrer-Policy` on every response, error pages included. `index.html` and SPA routes are `no-cache` so a deploy shows up at once. Hashed `/assets/*` files are cached for a year as `immutable`. HSTS is a chart value (`web.hsts`), off by default for installs without TLS (#260).
- Docs-vs-code drift: `docs/GOVERNANCE.md` previously asserted an Apache-2.0 `LICENSE` link whose target file did not exist.
- `stats_compute_ndv: false` was ignored, so batch runs paid for a full-table `compute_table_stats` scan on every optimized table (31% of lane time).
- The Spark renderer dropped every `rewrite_position_deletes` parameter (partial progress).
- Spark `expire_snapshots` for tables with protected snapshots called a procedure Iceberg does not have (`set_snapshot_ref`); it now tags the snapshot with `CREATE OR REPLACE TAG`.
- A batch lane whose pod was deleted (eviction, drain, spot reclaim) was never noticed and stranded its tables until the run deadline.
- Maintenance runs stayed `queued` forever after all their jobs finished: the run finalizer only looked at `running` runs, and maintenance runs are created `queued`. Finalizing also no longer drops the run's `actor`, requested `operations` and `correlation_id` from its summary.

## [0.0.0](https://github.com/tech-pw/cryo/blob/main/CHANGELOG.md) — Initial public release

Pre-release history predates this changelog. See `git log` for the full commit history.

Source: https://tech-pw.github.io/cryo/changelog/
Markdown: https://tech-pw.github.io/cryo/changelog/index.md