feat: Worktree navigation via wt go, launcher via wt open

docs/memory/wt-cli/index.md

@@ -8,6 +8,7 @@ description: "Behavior contracts for the `wt` CLI binary — commands, exit code
 | File | Description | Last Updated |
 |------|-------------|-------------|
 | [create-output-phases](create-output-phases.md) | Phase-separator output contract for `wt create` / `wt init` — Git/Init/Open separators on stderr, stdout reserved for the machine result. | 2026-06-20 |
+| [go-command-contract](go-command-contract.md) | `wt go` worktree-selection contract — selection-only navigation via `WT_CD_FILE`/stdout (no launch), exit codes, the current-worktree-included menu, and the `wt open --go` composition. | 2026-06-20 |
 | [help-dump-contract](help-dump-contract.md) | Contract for the hidden `wt help-dump` command — the JSON envelope shll.ai's scheduled puller consumes. | 2026-06-20 |
 | [idle-staleness-contract](idle-staleness-contract.md) | The shared idle predicate, the `wt delete --stale` selector, and the safety invariant that idleness never gates a deletion on its own. | 2026-06-20 |
 | [init-failure-contract](init-failure-contract.md) | Init-failure behavior of `wt create` / `wt init` — kept-worktree contract, `ExitInitFailed`, SIGINT handling, and terminal-foreground reclaim. | 2026-06-20 |

docs/memory/wt-cli/menu-navigation-contract.md

@@ -79,6 +79,12 @@ This file documents the contract that `ShowMenu` honors after the arrow-key navi
   - Both validation error messages: `Invalid choice. Please enter a number.` and `Invalid choice. Please enter a number between 0 and N.`
 - Existing test harnesses driving `ShowMenu` via piped stdin continue to pass unmodified. Integration tests under `cmd/integration_test.go` invoke the binary with pipes and naturally land on the fallback path.
 
+### `wt go` is a new `ShowMenu`/`MenuSession` caller (`260620-3pp5`)
+
+- The `260620-3pp5-open-worktree-from-worktree` change added `wt go` (and `wt open --go`), whose worktree-selection menu renders through the **shared** `selectWorktree(ctx, session, prompt)` helper (`src/cmd/wt/open.go`) — which calls `session.Show(...)` → `ShowMenu`. No new menu primitive was introduced; `wt go`'s picker inherits this contract wholesale (arrow keys, digit-submit, Cancel→`0`, wrap-around, the `(default)` marker, and the in-place redraw) with no `menu.go` edits.
+- **Non-TTY fallback**: `wt go`'s no-arg menu degrades through the same byte-identical numbered-prompt fallback as every other caller — `isInteractiveTTY()` gates it, and piped/CI invocations land on the historical numbered prompt automatically. `wt go` adds a separate, earlier guard for the **`--non-interactive` no-arg** case: it refuses with `ExitGeneralError` *before* reaching `selectWorktree` at all (a no-arg selection has no non-interactive default — see `/wt-cli/go-command-contract.md`), so that path never renders even the fallback prompt. `wt go <name>` and `wt go` interactive both reach the menu only when a menu is actually wanted.
+- **Shared `MenuSession` for the launch-chaining callers**: `selectAndOpen` and `wt open --go`'s `openGo` pass ONE `MenuSession` to both `selectWorktree` (the "Select worktree…" menu) and `handleAppMenuWithSession` (the "Open in:" menu), so the two consecutive menus share a single stdin reader — the documented byte-theft fix. `wt go` chains no second menu, so it uses a one-shot session. The single-reader requirement and why it matters are the `MenuSession` contract this file's navigation behavior sits on.
+
 ### Pure `nextMenuState` and `parseKey` are testable without a PTY
 
 - `nextMenuState(prev menuState, key keyEvent) menuStateTransition` is a **pure function** with no I/O, no globals, no clock. It encodes every key-mapping, wrap-around, digit boundary, and Cancel transition.
@@ -153,4 +159,5 @@ Originally `paintMenu` and `redrawMenu` had two parallel rendering paths — the
 - Tests: `src/internal/worktree/menu_test.go` — `nextMenuState` table-driven coverage (every keybinding, wrap-around, digit boundaries, seeding), `parseKey` table-driven coverage (arrow sequences, bare-Esc-vs-arrow timeout via fake clock, unknown sequences), fallback-path byte-equality tests, `TestRunInteractiveMenuCore_PanicRestore` (defer-restore guarantee), `TestPaintAndRedrawShareCore` (first-paint / redraw byte-equality).
 - Constitution: Principle I (Single-Binary CLI — motivated rejecting third-party TUI deps), Principle IV (Test What the User Sees — motivated the pure state-machine seam), Principle VI (Interactive by Default, Scriptable on Demand — motivated the byte-identical non-TTY fallback).
 - Sibling memory: `wt-cli/init-failure-contract.md` (different `wt` subcommand, same post-change invariant-capture pattern), `wt-cli/list-status-contract.md` (different subcommand, same pattern).
-- Call sites (informational, not edited by this change): `src/cmd/wt/open.go` (2 calls), `src/cmd/wt/delete.go` (7 calls), `src/cmd/wt/create.go` (2 calls).
+- Sibling memory: `wt-cli/go-command-contract.md` — the `wt go` selector / `wt open --go` composition whose worktree-selection menu is a new caller of this contract (via the shared `selectWorktree` → `ShowMenu`/`MenuSession`).
+- Call sites (informational): `src/cmd/wt/open.go` (the shared `selectWorktree` → `session.Show`, plus the "Open in:" menu, plus `wt open --go`'s `openGo`), `src/cmd/wt/go.go` (`wt go`'s no-arg selection menu, via `selectWorktree`; added by `260620-3pp5`), `src/cmd/wt/delete.go` (7 calls), `src/cmd/wt/create.go` (2 calls).

docs/memory/wt-cli/recency-ordering-contract.md

@@ -77,12 +77,12 @@ explicit spec amendment supersedes them.
 
 ### Open / delete menus list non-main worktrees newest-first
 
-- `selectAndOpen` (`src/cmd/wt/open.go`) and `handleDeleteMenu`
-  (`src/cmd/wt/delete.go`) build a `wtOption` slice of non-main worktrees
-  (the main worktree / `ctx.RepoRoot` is skipped) and sort it with
-  `wt.SortByRecency` so the **newest worktree appears at the top** of the menu.
-  This replaces the previous behavior where items appeared in porcelain order and
-  only the newest was highlighted.
+- `selectAndOpen` (`src/cmd/wt/open.go`, via the shared `selectWorktree` helper as
+  of `260620-3pp5` — see below) and `handleDeleteMenu` (`src/cmd/wt/delete.go`)
+  build a `wtOption` slice of non-main worktrees (the main worktree /
+  `ctx.RepoRoot` is skipped) and sort it with `wt.SortByRecency` so the **newest
+  worktree appears at the top** of the menu. This replaces the previous behavior
+  where items appeared in porcelain order and only the newest was highlighted.
 - The pre-selected menu default remains the **most-recent** worktree — this is
   behavior-preserving for the default selection. Only the item *ordering* changed.
 - `wt open`: `defaultIdx = 1` (newest is the first menu item; index 0 is the
@@ -95,6 +95,23 @@ explicit spec amendment supersedes them.
 - The two menus produce identical non-main ordering (both driven by the same
   `SortByRecency` call), so `wt open` and `wt delete` never disagree on order.
 
+### `wt go`'s no-arg menu is a new `SortByRecency` consumer (`260620-3pp5`)
+
+- The `260620-3pp5-open-worktree-from-worktree` change extracted the
+  `selectAndOpen` menu logic into the shared `selectWorktree(ctx, session,
+  prompt)` helper (`src/cmd/wt/open.go`), which calls `wt.SortByRecency` over its
+  local `wtOption` slice (filtering out the main repo, `defaultIdx = 1`). That
+  single helper now backs **three** menu callers — `wt open` (main-repo no-arg,
+  prompt "Select worktree to open:"), `wt go` (no-arg, prompt "Select worktree to
+  go to:"), and `wt open --go` (no-arg). So `wt go`'s selection menu is a new
+  consumer of the same newest-first ordering, joining `wt list` / `wt open` /
+  `wt delete` — there is still exactly one `SortByRecency` call site for the
+  open/go selection menu, not a per-verb copy.
+- The ordering, branch display, and newest-default are byte-identical across all
+  three callers because they share the one helper. See
+  `/wt-cli/go-command-contract.md` for the `wt go` / `wt open --go` behavior
+  contract and the `selectWorktree` extraction details.
+
 ### `wt delete` menu: stale-aware annotation + "All idle" (`260530-5fyu`)
 
 - `handleDeleteMenu` (`src/cmd/wt/delete.go`) now annotates each idle non-main
@@ -188,6 +205,9 @@ produced.
   (built on the `RecencyOf` signal documented here), `DefaultIdleThreshold`, and
   the `wt delete --stale` selector; the authoritative cross-command idle contract
   behind the `defaultIdx` 2/3 shift and `, idle` annotation noted above.
+- Sibling memory: `wt-cli/go-command-contract.md` — the `wt go` selector and
+  `wt open --go` composition; the new `selectWorktree` menu consumers of the
+  `SortByRecency` ordering documented here.
 - Spec doc: `docs/specs/cli-surface.md` — `wt list` (`--sort` flag), `wt open`
   (selection menu, "most recently modified worktree" default), `wt delete`
   (selection menu).
@@ -196,7 +216,8 @@ produced.
   `<repo>.worktrees/<name>/` root.
 - Source: `src/internal/worktree/recency.go` — `RecencyOf`, `RecencyLess`,
   `SortByRecency`.
-- Source: `src/cmd/wt/open.go` (`selectAndOpen`), `src/cmd/wt/delete.go`
+- Source: `src/cmd/wt/open.go` (`selectWorktree` shared helper + `selectAndOpen`;
+  `selectWorktree` is also called by `wt go` and `wt open --go`), `src/cmd/wt/delete.go`
   (`handleDeleteMenu` — now stale-aware: `firstWorktreeIdx`/`defaultIdx` 2/3,
   `, idle` annotation, "All idle (N)"; plus `handleDeleteStale`), `src/cmd/wt/list.go`
   (`sortEntries`, `resolveSort`).

docs/specs/cli-surface.md

@@ -75,13 +75,16 @@ Exit codes: `ExitInvalidArgs` if `--path` is combined with `--json` or
 ## `wt open [name|path]`
 
 Open a directory in a detected application (editor, terminal, file manager).
-`wt open` is the canonical directory launcher — external callers (notably
+`wt open` is the canonical directory **launcher** — external callers (notably
 `hop`) MAY delegate to it via subprocess invocation. The full env-var contract
-is documented in [`launcher-contract.md`](launcher-contract.md).
+is documented in [`launcher-contract.md`](launcher-contract.md). Worktree
+**selection** (picking which worktree) is the job of [`wt go`](#wt-go-name);
+`wt open --go` composes the two (select, then launch).
 
 | Flag | Default | Description |
 |------|---------|-------------|
 | `--app <name\|default>` | (none) | Open directly in the named app, skipping the menu. `default` selects the auto-detected default. |
+| `--go` | `false` | Select a worktree first (via `wt go`'s menu when no name is given, or resolve-by-name when one is), then launch it. Requires a git repository; composes with `--app`. From a non-git cwd, exits `ExitGitError`. |
 
 Positional arg `[name|path]`:
 
@@ -98,12 +101,50 @@ Positional arg `[name|path]`:
   reachable when the cwd is inside a git repo.
 
 Exit codes: `ExitInvalidArgs` when `--app` is used with the main-repo selection
-menu; `ExitGitError` only when a git operation fails during name resolution
-(not for path-only or no-args invocations from outside a repo);
+menu; `ExitGitError` when a git operation fails during name resolution, or when
+`--go` is invoked from a non-git cwd (the `--go` git-repo precondition) — but
+not for path-only or no-args invocations from outside a repo;
 `ExitByobuTabError` / `ExitTmuxWindowError` for terminal-app failures;
 `ExitGeneralError` for unknown apps, unresolved targets, or name args supplied
 from a non-git cwd.
 
+## `wt go [name]`
+
+Select a worktree of the current repository and **navigate** there. `wt go` is
+the worktree **selector** (the counterpart to `wt open`, the launcher): it
+changes the shell's working directory to the chosen worktree and launches
+nothing. Navigation reuses the same `WT_CD_FILE` shell-cd plumbing as the
+launcher's "Open here" option — see [`launcher-contract.md`](launcher-contract.md) §3.
+
+| Flag | Default | Description |
+|------|---------|-------------|
+| `--non-interactive` | `false` | No prompts. With no name, refuses deterministically (a no-arg selection menu has no non-interactive default) instead of prompting. |
+
+Positional arg `[name]`:
+
+- Omitted: shows a worktree-selection menu for the current repo (newest-first,
+  branch shown per entry, newest pre-selected as default). Reachable from
+  anywhere in the repository — the main repo **or** inside another worktree.
+  On selection, navigates to the chosen worktree.
+- Provided: resolved as a worktree name (case-insensitive); navigates there
+  directly with no menu.
+
+`wt go` always **requires a git repository** — worktree resolution walks the
+repo's worktree list. It is scoped to the current repo's worktrees only;
+cross-repo navigation is `hop`'s job.
+
+Navigation mechanism: the resolved absolute path is written to `WT_CD_FILE`
+(when set; mode `0600`, truncate-on-write) so the `wt shell-init` wrapper cd's
+the parent shell there, **and** is printed to stdout as the last line so the
+no-wrapper scripting form works: `cd "$(command wt go some-name)"`. When
+`WT_CD_FILE` is unset and `WT_WRAPPER` is not `1`, the same "shell wrapper not
+loaded" hint the launcher prints applies. `wt go` never cd's the parent shell
+directly.
+
+Exit codes: `ExitGitError` (3) when the cwd is not in a git repository or
+`git worktree list` fails; `ExitGeneralError` (1) for an unknown worktree name,
+or for a no-arg invocation under `--non-interactive`.
+
 ## `wt delete [worktree-names...]`
 
 Delete one or more worktrees with optional branch cleanup.

docs/specs/launcher-contract.md

@@ -59,6 +59,17 @@ existing directory and the cwd is in a git repo.
 When `WT_CD_FILE` is unset, "Open here" falls back to printing `cd -- '<path>'`
 to stdout (single-quoted with `'\''` escaping for shell safety).
 
+**Reused by `wt go`.** The `wt go` selector (see
+[`cli-surface.md`](cli-surface.md#wt-go-name)) navigates to a worktree using
+this **same** `WT_CD_FILE` mechanism — no new environment variable is
+introduced. It writes the resolved absolute path to `WT_CD_FILE` with the
+identical semantics above (mode `0600`, truncate-on-write, contents = resolved
+directory path), and additionally always prints the path to stdout as the last
+line (so `cd "$(command wt go <name>)"` works without the wrapper). Because
+`wt go` adds no new env-var name and does not alter any semantics in this
+section or §5, the stability guarantees in §6 are unchanged — no constitution
+amendment is required.
+
 ## 4. `WT_WRAPPER`
 
 `WT_WRAPPER=1` signals that the caller is handling the `cd` itself (via

fab/changes/260620-3pp5-open-worktree-from-worktree/.history.jsonl

@@ -0,0 +1,12 @@
+{"action":"enter","driver":"fab-new","event":"stage-transition","stage":"intake","ts":"2026-06-20T05:44:24Z"}
+{"args":"There's no easy way to open a worktree from another worktree. wt open seems like the command that should do this, but right now it opens the current folder. Thinking holistically, I am also fine transferring the responsibility of 'opening folders' to the hop command, and make wt open open a worktree and delegate to hop open","cmd":"fab-new","event":"command","ts":"2026-06-20T05:44:24Z"}
+{"delta":"+4.6","event":"confidence","score":4.6,"trigger":"calc-score","ts":"2026-06-20T06:46:53Z"}
+{"delta":"+0.0","event":"confidence","score":4.6,"trigger":"calc-score","ts":"2026-06-20T06:46:58Z"}
+{"cmd":"fab-fff","event":"command","ts":"2026-06-20T06:47:41Z"}
+{"action":"enter","driver":"fab-fff","event":"stage-transition","stage":"apply","ts":"2026-06-20T06:47:47Z"}
+{"action":"enter","driver":"fab-fff","event":"stage-transition","stage":"review","ts":"2026-06-20T06:56:54Z"}
+{"action":"enter","driver":"fab-fff","event":"stage-transition","stage":"hydrate","ts":"2026-06-20T07:03:18Z"}
+{"event":"review","result":"passed","ts":"2026-06-20T07:03:18Z"}
+{"action":"enter","driver":"fab-fff","event":"stage-transition","stage":"ship","ts":"2026-06-20T07:08:00Z"}
+{"action":"enter","driver":"git-pr","event":"stage-transition","stage":"review-pr","ts":"2026-06-20T07:09:37Z"}
+{"event":"review","result":"passed","ts":"2026-06-20T07:15:49Z"}

fab/changes/260620-3pp5-open-worktree-from-worktree/.status.yaml

@@ -0,0 +1,53 @@
+id: 3pp5
+name: 260620-3pp5-open-worktree-from-worktree
+created: 2026-06-20T05:44:24Z
+created_by: sahil-noon
+change_type: feat
+issues: []
+progress:
+    intake: done
+    apply: done
+    review: done
+    hydrate: done
+    ship: done
+    review-pr: done
+plan:
+    generated: true
+    task_count: 9
+    acceptance_count: 20
+    acceptance_completed: 20
+confidence:
+    certain: 4
+    confident: 4
+    tentative: 0
+    unresolved: 0
+    score: 4.6
+    fuzzy: true
+    dimensions:
+        signal: 78.1
+        reversibility: 77.5
+        competence: 86.9
+        disambiguation: 79.4
+stage_metrics:
+    intake: {started_at: "2026-06-20T05:44:24Z", driver: fab-new, iterations: 1, completed_at: "2026-06-20T06:47:47Z"}
+    apply: {started_at: "2026-06-20T06:47:47Z", driver: fab-fff, iterations: 1, completed_at: "2026-06-20T06:56:54Z"}
+    review: {started_at: "2026-06-20T06:56:54Z", driver: fab-fff, iterations: 1, completed_at: "2026-06-20T07:03:18Z"}
+    hydrate: {started_at: "2026-06-20T07:03:18Z", driver: fab-fff, iterations: 1, completed_at: "2026-06-20T07:08:00Z"}
+    ship: {started_at: "2026-06-20T07:08:00Z", driver: fab-fff, iterations: 1, completed_at: "2026-06-20T07:09:37Z"}
+    review-pr: {started_at: "2026-06-20T07:09:37Z", driver: git-pr, iterations: 1, completed_at: "2026-06-20T07:15:49Z"}
+prs:
+    - https://github.com/sahil87/wt/pull/23
+change_type_source: explicit
+true_impact:
+    added: 0
+    deleted: 0
+    net: 0
+    excluding:
+        added: 0
+        deleted: 0
+        net: 0
+    computed_at: "2026-06-20T07:08:00Z"
+    computed_at_stage: hydrate
+summary: Add wt go (current-repo worktree selection, WT_CD_FILE+stdout navigation, no launch) and wt open --go composition; extract shared selectWorktree helper
+# true_impact: lazily created on first apply-finish (no placeholder here).
+last_updated: 2026-06-20T07:15:49Z