Changelog / Always moving forward
What’s new.
What’s next for you.
A better way to read, review, and understand your code. Every release, every improvement, all in one place.
Already have Tachyon? You’re one command away.
curl -fsSL https://www.tachyon.run/install.sh | bashRelease history / 9 releases
Get the latest releaseRust can now update itself.
What changed
- FIXEDtachyon --update now works in the Rust engine: it checks the latest release and atomically replaces the running binary, with the daily background update notice wired up too
How to update Already have Tachyon? Re-run the installer to update, or run tachyon --update. No config migration needed.
curl -fsSL https://www.tachyon.run/install.sh | bashYour agent's work, explained and verified.
Highlights
Every agent edit arrives with a Why? card
As your agent edits, it leaves a short note per file: what changed, why, the decision it took, and the risks for you. Tachyon locks each note to the exact code and shows a ✓ verified card on the diff. If the code moves afterwards, the card flips to stale instead of pretending nothing happened.
Try it: Edit one file with your agent, open tachyon Review, and look for the ✓ verified card.
Your agent plugs straight into your codebase
Tachyon now serves your repo over MCP: find files, search code, outline files, jump to definitions, pull a full context pack, and record intent, from Claude Code, Cursor, Codex, opencode, or anything that speaks MCP. Tools advertise their schemas, so agents discover and call them correctly.
Try it: Run tachyon mcp . and register it once in your agent's MCP settings.
No server? Take a pack.
One command bundles everything about a change (changed files, symbols, references, related tests, and an evidence score) into a single JSON file you can hand to any agent, online or off.
Try it: tachyon context --max-files=10 . > pack.json, then hand pack.json to your agent.
Measured, not promised: 27.8s → 2.7s
Same job three ways: track down a symbol, find every use, find its tests. Digging with shell commands takes 27.8s; a Tachyon context pack does it in 2.7s with one round trip. Narrow the search and answers land in milliseconds.
Try it: Time it on your own repo: a manual grep hunt versus one tachyon context call.
More in this release
- FIXEDtachyon --dev now resolves relative targets where the command ran. The dev child inherits your working directory instead of resetting to the checkout root
How to update Already have Tachyon? Re-run the installer to update. No config migration needed.
curl -fsSL https://www.tachyon.run/install.sh | bashSame UI, same API, same flags: new binary.
Highlights
A smaller, faster Tachyon
Tachyon now ships as a 5.5 MB Rust binary, less than half the 12 MB Go download. For you, nothing changes: same flags, same API, same UI, same install command. It just downloads faster, starts faster, and searches faster.
Try it: Run the install command again: that's the whole upgrade.
Big repos open before you blink
Indexing is 1.6 to 4x faster across the board: the Linux kernel in ~330 ms instead of ~520 ms, Django in 48 ms instead of 137 ms, Redis in 6 ms instead of 23 ms. Your checkout is ready before you've lifted your finger.
Try it: tachyon ~/src/linux: the kernel is ready in about a third of a second.
Heavy searches stay light
Worst-case searches, where a query matches nothing so every byte gets read, run up to 2x faster: the kernel in 1.7 s instead of 3.8 s, Kubernetes in 380 ms instead of 666 ms. And Tachyon holds less memory on every repo we measured, leaving your machine free for everything else.
Try it: Search a huge repo for something that matches nothing: fast, with memory staying flat.
Nothing breaks, anywhere
Every platform keeps working. Where a native Rust build isn't available yet, the installer automatically hands you the identical Go build, with the same UI, same flags, and same results. You never have to think about which engine you're on.
Try it: Same install command on any platform. You always get the best build for your machine.
Go vs Rust, measured
| Repo | Files | Index Go | Rust | Fuzzy Go | Rust | Full scan Go | Rust | Mem Go | Rust | Peak Go | Rust |
|---|---|---|---|---|---|---|
| django | 7,014 | 137 ms48 ms | 0.7 ms0.7 ms | 70.4 ms68.5 ms | 33 MB26 MB | 43 MB42 MB |
| flask | 235 | 4 ms1 ms | 0.5 ms0.5 ms | 2.7 ms2.6 ms | 28 MB19 MB | 30 MB24 MB |
| kubernetes | 25,894 | 221 ms138 ms | 1.1 ms1.2 ms | 665.8 ms379.7 ms | 47 MB37 MB | 77 MB109 MB |
| linux | 95,696 | 520 ms327 ms | 1.2 ms1.4 ms | 3779.3 ms1695.7 ms | 86 MB58 MB | 293 MB71 MB |
| react | 7,190 | 79 ms34 ms | 0.9 ms0.7 ms | 92.1 ms92.7 ms | 34 MB29 MB | 44 MB50 MB |
| redis | 1,866 | 23 ms6 ms | 0.6 ms0.5 ms | 19.7 ms16.5 ms | 30 MB22 MB | 38 MB39 MB |
| typescript | 66,558 | 671 ms291 ms | 1.5 ms2.1 ms | 1939.1 ms1613.0 ms | 70 MB54 MB | 110 MB87 MB |
| Base · before indexing | ~25 MB~14 MB (empty directory, idle server, ps RSS) | |||||
Measured 2026-09-16 on Apple M3 Max / macOS arm64 (14 cores), tachyon 1.0.0: both engines back to back on the same repos, best-of-5 runs. Times are best of 5; Mem/Peak are server RSS. Binaries: Go 12 MB, Rust 5.5 MB.
Rust sweeps indexing on all 7 repos (1.6 to 4x) and takes full scans everywhere it matters (kernel 3.78 s → 1.70 s, kubernetes 666 → 380 ms, TypeScript 1939 → 1613 ms), with lower resident memory on all 7. Peak is noisier. Rust wins decisively on the big trees (kernel 71 vs 293 MB, TypeScript 87 vs 110 MB) and lands within a few MB either way on the small ones. Fuzzy find is a wash at this resolution.
File counts match across engines on every repo (same ignores, same index), and find/tree/search payloads are byte-identical between engines, with the same ranking and the same JSON.
Faster everywhere. At home in every checkout.
Highlights
Read your docs where you work
Markdown files now open with source and rendered preview side by side: headings, tables, task lists, strikethrough, and fenced code all render safely. Flip between Code, Split, and Preview without losing your place.
Try it: Open any .md file, then Ctrl+Shift+M to switch Code / Split / Preview.
Switch checkouts without losing your place
A new switcher in the top bar jumps between worktrees with branch, health, and dirty-file badges. Your review follows along, open tabs park safely, and everything restores when you switch back.
Try it: Top-bar switcher → pick a worktree, Ctrl+Shift+T brings a parked tab back.
Every hover tells you who and when
Hover cards now answer two questions at once: what is this, and who touched it last. Definitions appear instantly with an author, date, and message footer that clicks straight through to History.
Try it: Hover any symbol, then click the blame footer to open History.
Keeps working when the server doesn't
Trees and open files are cached for offline reading. If the server goes down, your work stays on screen with a clear “cached” note instead of a blank page, and everything revalidates when you're back.
Try it: Open a file, stop the server, reopen: your tree and file are still there.
More in this release
- NEWAppearance prefs: font size, line height, fonts, comfortable/compact density, accent color, minimap, and current-line highlight, all in one place
- NEWPalette and symbol search now filter in the background, so typing stays smooth on huge repos
- NEWSearch is cancellable: fast typing aborts stale scans instead of stacking them up
- NEWAdaptive performance: lighter rendering on low-power devices, slow networks, and reduced-motion setups
- BETTERSecond loads feel near-instant thanks to smarter caching of the app shell and styles
- BETTERFaster indexing, highlighting, and fuzzy search across large trees
- BETTERSmoother scrolling: idle-scheduled rendering, next-chunk and hover prefetch, no layout jank
- BETTERQuieter background: metrics, live updates, and git polling pause in hidden tabs and resume where they left off
- FIXEDOffline trees no longer pin a stale folder. The next click retries the network
- FIXEDFast typing no longer piles up server-side searches
How to update Already have Tachyon? Re-run the installer to update. No config migration needed.
curl -fsSL https://www.tachyon.run/install.sh | bashThe whole branch. A clearer review.
Highlights
Review an entire branch
Pick the Branch comparison and Tachyon lays out the full diff against any base (branch, commit, or ref) with live file and line counts in a dedicated branch bar.
Try it: Review panel → Compare → Branch, type main in the base field.
Read all changes in one scroll
One switch stacks the whole comparison into a single scrollable view with sticky file headers, so you can read a branch top to bottom. File steppers hop between files and keep the sidebar in sync.
Try it: Review: Show All Changes from the palette.
Tachyon now speaks git
Your branch and dirty-file count live in the status bar, every file wears its git badge, and a new History inspector brings file log, view-at-any-revision, and blame, all updating quietly as you commit or switch branches.
Try it: Git: Blame Current File from the palette.
More in this release
- NEWFiles and Review get their own sidebar tabs, and your place is restored when you reopen
- NEWWord wrap (on by default) and line numbers are now remembered between sessions
- NEWStart Tachyon explicitly with tachyon run [dir]
- BETTERReview panel refresh: an “N of M reviewed” progress bar, file filter, per-file +/− badges, and a shortcut footer
- BETTERDiff toolbar polish: position readouts on steppers, a unified/split toggle, a Mark-reviewed button that explains itself when disabled, auto-advance after marking, Esc to close
- BETTERCleaner diffs: change markers only where they matter, full-width no-newline markers, dual gutters in unified view, per-side line numbers in split
- BETTERShortcuts rebuilt around the browser: no more Alt clashes, everything on Ctrl/Cmd+Shift with per-OS labels; tab close is now Ctrl+Shift+W
- BETTERA failed start now offers a retry button instead of a stuck Loading screen, and background re-indexes can no longer leave the file tree and search disagreeing
- BETTERSame speed, far less memory: Tachyon now idles around 16 MB
- FIXEDMemory readout is now accurate on macOS
- FIXEDClosing a tab no longer freezes the UI
How to update Already have Tachyon? Re-run the installer to update. No config migration needed.
curl -fsSL https://www.tachyon.run/install.sh | bashMore context. Smarter navigation.
Highlights
One language server per worktree
Every checkout gets its own isolated server session, so definitions in one worktree never leak into another. A Problems view and stale-location guards keep navigation honest.
Try it: Open the same file in two worktrees and compare definitions.
Java that actually resolves
Full cross-file definitions for Maven and Gradle projects, with the server runtime detected independently of your project JDK.
Try it: F12 on a cross-file Java symbol.
Spring and Kotlin join in
Spring Boot language support with automatic workspace discovery, plus experimental Kotlin support.
Try it: Open the outline view in a Spring service class.
More in this release
- NEWLanguage servers for JVM languages are found automatically. No setup needed
- BETTERServer setup now streams live progress instead of going quiet
Meet your review workbench.
Highlights
A workbench for reviews
Pick a task, see only the files that changed, and read fast unified or split diffs. Your view pins a snapshot, so agent edits never yank the code out from under you. A gentle nudge offers the refresh when you're ready.
Try it: Cmd/Ctrl+Shift+G, open a file, keep the agent running.
Reviewed means reviewed
Marks attach to the exact version you read. The moment either side changes, the mark goes stale, so “reviewed” always means something.
Try it: Cmd/Ctrl+Shift+R, then edit the file and watch the mark go stale.
Every comparison, live
Unstaged, staged, since-you-started-watching, checkpointed, or whole branch: all streaming live, with follow and pause.
Try it: Cmd/Ctrl+Shift+V to pause mid-review.
More in this release
- NEWReview service: per-worktree diffs, live watching, checkpoints, review marks, and worktree management
- NEWRock-solid foundations: immutable snapshots, an exact-version review store, and a native git engine
- BETTERSelf-updates now point at Tachyon releases
- BETTERReview data formats are frozen and tested, so updates never lose your marks
A smoother start.
What changed
- FIXEDInstalling no longer touches your shell aliases. Just a standard PATH setup, no prompts
- FIXEDReview group headers collapse like folders instead of disappearing until reload
A little more clarity starts here.
Highlights
Opens before you blink
A single self-contained binary with zero dependencies and a ~16 MB footprint. A 400,000-line file opens as fast as a 10-line one.
Try it: tachyon ~/src/linux. Indexed before you lift your finger.
Find anything in milliseconds
Fuzzy file, symbol, and project search that understands word boundaries.
Try it: Cmd/Ctrl+P, type two word fragments.
280 languages, 14 themes
Beautiful highlighting everywhere, plus definitions, references, outlines, and call trails for Go, Rust, TypeScript, Python, C/C++, and more.
Try it: F12 on any symbol.
More in this release
- NEWOne-line installer. Run it again any time to update
- NEWLocal-first: runs on 127.0.0.1 only. No accounts, no telemetry