[BUG]: Project ID collision when repos cloned from same source share sessions

[bcheung]

Repos cloned from the same source share the same root commit hash, causing them to share sessions unexpectedly. Opening opencode in either repo shows sessions from both.

Affected workflows

• Cloned templates (e.g., create-react-app, Next.js starters)
• Forks
• Any "clone and change origin" workflow

Reproduction

#!/bin/bash
set -e

WORKDIR=$(mktemp -d)
cd "$WORKDIR"

# Create template repo and clone it twice
mkdir template && cd template
git init -q && echo "template" > README.md && git add . && git commit -qm "init"
cd "$WORKDIR"
git clone -q template clone-a
git clone -q template clone-b

# Run opencode in each
(cd "$WORKDIR/clone-a" && opencode run "respond with only: session from clone-a")
(cd "$WORKDIR/clone-b" && opencode run "respond with only: session from clone-b")

# Verify collision
echo "clone-a project ID: $(cat "$WORKDIR/clone-a/.git/opencode")"
echo "clone-b project ID: $(cat "$WORKDIR/clone-b/.git/opencode")"
# Both are identical - opening opencode in either shows sessions from both

Root cause

Project ID is derived from the first root commit hash:

https://github.com/anomalyco/opencode/blob/038cff4a93bb39238534898b4790229773c4ff22/packages/opencode/src/project/project.ts#L57-L72

Related

• #5638 - Same root cause but for git worktrees. PR #5647 fixes worktrees by adding worktree hash, but cloned repos aren't worktrees so they still collide.

Notes on solution

The fix probably needs to be conditional:

• Worktree → Share project ID with main repo (current behavior is correct for this case)
• Git repo (not worktree) → Need deterministic unique ID that doesn't collide across clones. Root commit alone isn't sufficient. Options: include absolute path in hash, or remote origin URL, or generate UUID on first run.
• Not a git repo → Could use absolute path

Key insight: PR #5647 correctly handles worktrees. This issue is specifically about the non-worktree clone scenario.

Side note: worktree caching

In git worktrees, .git is a file (not directory) pointing to .git/worktrees/<name>/. The current cache write to .git/opencode fails silently. Depending on the solution chosen here, this silent failure may cause issues if the fix relies on persisting something to that file.

https://github.com/anomalyco/opencode/blob/038cff4a93bb39238534898b4790229773c4ff22/packages/opencode/src/project/project.ts#L53-L56