Workspace-Aware Amicode: Multi-Directory Sessions + Workspace Sidebar

[jeonghun-jj-lee]

Workspace-Aware Amicode: Multi-Directory Sessions + Workspace Sidebar

Important

Decision Surface

Problem: Amicode sessions scope to a single workspace folder (workspaceFolders[0]).
In multi-root VS Code workspaces (Altissimo + DirectTrajOpt + Piccolo), the agent can
access other folders via absolute paths but (a) gets external-directory permission prompts,
(b) only loads instructions from the primary folder, and (c) the sidebar is a dead placeholder.

Approach: Extend the opencode engine's Location.Ref to carry multiple directories.
All workspace folders become "internal" to the session — no permission prompts, instructions
discovered from each, tools operate freely across all. The Amicode sidebar's "Armonia"
placeholder becomes a full "Workspace" file explorer mirroring the native VS Code Explorer.

Approaches Considered:

• (A) Multi-directory Location.Ref (chosen) — engine natively multi-root, cleanest model
• (B) Virtual worktree umbrella — additive worktrees[] field, smaller change but hacky
• (C) Extension-only shim — no engine changes, brittle injection of instructions + allowlists

Scope: opencode engine (packages/schema, packages/core, packages/server,
packages/opencode) + Amicode VS Code extension (sidebar, session creation, package.json).
Removes the Catalog sidebar view.

Assumptions:

• The V2 session system (packages/core) is the target; V1 gets compatibility propagation
• Single-folder workspaces behave identically to today (no regression)
• The directories field is optional/nullable — existing sessions remain valid

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Acceptance Criteria

1. Multi-directory session creation — when Amicode passes multiple workspace folders,
   the opencode session stores all of them and treats each as internal scope
2. No external-directory prompts — Bash, Read, Edit, Glob, Grep operating on any
   workspace folder path do NOT trigger the external-directory approval flow
3. Multi-root instruction discovery — CLAUDE.md / AGENTS.md / CONTEXT.md from each
   workspace folder are discovered via findUp and loaded into the system prompt (deduplicated by resolved path)
4. System prompt reflects workspace — the env block lists all workspace folders with
   the primary marked
5. Single-folder fallback — with one workspace folder, behavior is unchanged from current
6. Workspace sidebar — the Amicode activity bar shows a "Workspace" tree view that:
   • Renders all workspace folders as collapsible root nodes
   • Expands into the filesystem (files + directories, recursively)
   • Uses VS Code theme icons (file/folder icons from the active icon theme)
   • Shows git status decorations (modified, untracked, etc.)
   • Opens files in the editor on click
   • Full context menus: New File, New Folder, Rename, Delete, Copy Path, Copy Relative Path, Reveal in Finder, Open in Terminal
   • Respects files.exclude and .gitignore
   • Live-updates on filesystem changes
7. Catalog removed — the amicode.catalog tree view, SessionCatalogTree, and related commands are removed
8. DB migration — existing sessions continue to work (nullable directories column)

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Key Decisions

Engine: Location.Ref schema extension

// packages/schema/src/location.ts
export const Ref = Schema.Struct({
 directory: AbsolutePath, // primary CWD
 directories: optional(Schema.Array(AbsolutePath)), // all workspace roots
 workspaceID: optional(WorkspaceID),
})

• directory = primary folder (default CWD for Bash, relative path resolution)
• directories = full set of workspace folders (including the primary)
• When directories is absent/empty → single-root behavior (backward compat)

Engine: Boundary check expansion

The containsPath function (used by external-directory approval) expands:

• Check directory (primary)
• Check each entry in directories
• Check worktree (git root of primary)

Any hit → internal, no approval needed.

Engine: Instruction stacking

findUp runs independently from each directory in directories:

• Order: primary first, then remaining in workspace order
• Each findUp walks from its directory up to its own git worktree root
• Deduplicate by resolved absolute path
• All discovered instruction files are loaded and concatenated in order

Extension: Session creation

const collectionUrl = new URL("/session", server.url);
collectionUrl.searchParams.set("directory", workspaceFolders[0].uri.fsPath);
if (workspaceFolders.length > 1) {
 collectionUrl.searchParams.set("directories", JSON.stringify(
 workspaceFolders.map(f => f.uri.fsPath)
 ));
}

Extension: Sidebar architecture

• package.json: rename amicode.armonia → amicode.workspace, rename to "Workspace"
• Remove amicode.catalog view entirely
• New WorkspaceTreeProvider implements TreeDataProvider<WorkspaceItem>
• WorkspaceItem = { uri: vscode.Uri, type: vscode.FileType, workspaceFolder?: vscode.WorkspaceFolder }
• Root nodes = workspace folders; children = vscode.workspace.fs.readDirectory()
• File watcher: vscode.workspace.createFileSystemWatcher("**/*") → refresh affected subtree
• Git decorations: FileDecorationProvider reading from vscode.scm or the git extension API
• Context menus: contributed via menus.view/item/context in package.json, keyed on viewItem

Data Contracts

Session create request (HTTP):

POST /session
 ?directory=/Users/jj/.julia/dev/Altissimo
 &directories=["/Users/jj/.julia/dev/Altissimo","/Users/jj/.julia/dev/DirectTrajOpt","/Users/jj/.julia/dev/Piccolo"]

Session DB row (new column):

ALTER TABLE sessions ADD COLUMN directories TEXT; -- JSON array, nullable

System prompt env block:

Working directory: /Users/jj/.julia/dev/Altissimo
Workspace folders:
 - /Users/jj/.julia/dev/Altissimo (primary)
 - /Users/jj/.julia/dev/DirectTrajOpt
 - /Users/jj/.julia/dev/Piccolo
Is directory a git repo: yes
Platform: darwin

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Constraints & Invariants

• Backward compatibility — sessions created without directories work as before
• No hot-reload — changing workspace folders mid-session does not update existing sessions (new sessions pick up the change)
• Primary is always first — directories[0] === directory (the primary)
• Permission model unchanged — paths outside ALL workspace folders still trigger external-directory approval
• No cross-worktree git — each directory's findUp stops at its own git root, not at a shared ancestor

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Prior Art

• VS Code's native Explorer handles multi-root via workspaceFolders array
• The existing MoveSession concept in opencode (relocating a session to a different directory) shows the engine already treats directory as mutable
• The sandboxes: string[] field on Project is a precedent for tracking multiple related directories

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Source

Brainstorming session, 2026-08-19. Resolved through collaborative design interview.

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Notes

• The Catalog view (SessionCatalogTree) is removed. If pulse catalog access is needed later, it can live in the chat panel or a dedicated webview.
• The workspace sidebar is intentionally a mirror of VS Code's Explorer — same UX expectations, same keyboard shortcuts where possible.
• This design targets the V2 session system (packages/core). V1 (packages/opencode) gets compatibility propagation but is not the primary implementation target.