Claude Desktop Cowork Sessions

Overview

Cowork is Claude Desktop's local agent mode. A session runs an agent that can use tools on the user's machine: shell commands, file reads and writes, web fetches, and connected MCP tools. Each session leaves a directory of evidence that records what the agent was asked, which folders it could reach, what it did, and what it produced.

Cowork evidence is the strongest local record of agent activity in the app. The companion page Cowork Audit Log covers the tamper-evident event log. This page covers everything else in the session tree.

File Locations

Root: ~/Library/Application Support/Claude/local-agent-mode-sessions/<accountUuid>/<orgUuid>/

The account and organization UUIDs in the path are the same identifiers that appear in the conversation store and config.json, so they link a session to an account.

Session Metadata

local_<uuid>.json is a single JSON object per session.

Field names above were observed on the reference build, and the set changes between versions. Unknown fields should be preserved, not discarded.

What to Look For

• Granted folders. user_selected_folders is the scope of data the agent could read and write. Compare it to files the transcript shows being touched.
• Egress. egress_allowed_domains and web_fetch_allowed_urls bound where the agent could send data. A permissive list matters in an exfiltration question.
• Remote MCP servers. remote_mcp_servers names third-party services the agent could call, with URLs.
• Session type. scheduled and dispatch_child sessions can run without the user watching. Check scheduled_task_id and the space's scheduled-tasks.json.

Output and Upload Files

outputs/ holds what the agent wrote for the user and uploads/ holds what the user attached. For each file record the relative path, size, SHA-256, and the file system modified and birth times. These are original files, so their contents and their metadata both matter. A file in outputs/ was created by the agent, which is evidence of what it produced, and the file times are the best available timing of when.

Embedded Claude Code Transcripts

Cowork runs an embedded Claude Code agent. Its working state lives in local_<uuid>/.claude/, which mirrors the layout of ~/.claude/ for the standalone CLI.

Transcript JSONL

.claude/projects/<mangled-cwd>/<cliSessionId>.jsonl holds one JSON object per line. The directory name is a mangled form of the working directory (separators replaced; the exact scheme is inferred, so match on the session ID instead), and the file name is the CLI session ID from the session metadata. Entries are user and assistant messages with typed content blocks:

Sub-agent work appears in separate subagents/*.jsonl files under the session directory. .claude/tasks/ holds the agent's task lists, which show how it planned the work.

The transcript overlaps with the audit log. Use the transcript for the conversational flow and the audit log for ordering, permission decisions, and tamper evidence. Entries that appear in one and not the other deserve explanation.

Spaces

A space groups sessions, projects, and scheduled work for an account and organization.

Scheduled tasks and installed skills are both execution and persistence surfaces: one makes the agent act on a timer, the other changes how it behaves.

Claude Code Sessions in the Desktop App

When the desktop app launches Claude Code sessions, it keeps a registry separate from Cowork:

These records only link to the session. The full transcripts for those sessions are under ~/.claude/projects/, outside this profile. A .corrupt-<ms> copy means the app set aside an unreadable registry and started a new one, which can preserve older entries.

Virtual Machine Bundle

Cowork runs tools in a Linux virtual machine whose files live in Claude/vm_bundles/claudevm.bundle/: a root file system image (rootfs.img), a session data image (sessiondata.img), kernel and initrd files, efivars.fd, machineIdentifier, gvisorMacAddress, and vmIP. These are very large. macfor hashes and records them by default and copies them only on request. The images were not parsed during the research, so what the guest file systems contain is not documented here. The machineIdentifier, MAC address, and IP show the guest's identity and may appear in network logs.

Timestamps

What macfor Collects

The ai.claudedesktop plugin emits claude_cowork_session, claude_cowork_file, agent_transcript_entry, agent_task, claude_space, claude_artifact, claude_scheduled_task, claude_project_cache, claude_skill, claude_code_session, claude_git_worktree, and claude_vm_file records. Transcripts and output and upload files are copied byte-for-byte, unless skip_content or skip_cowork_files is set.

{
  "type": "claude_cowork_session",
  "session_id": "local_00000000-0000-4000-8000-000000000002",
  "session_type": "local-1p-cowork",
  "title": "Example session",
  "model": "example-model",
  "cwd": "/Users/jdoe/Documents/example",
  "user_selected_folders": ["/Users/jdoe/Documents/example"],
  "egress_allowed_domains": ["example.com"],
  "created_at": "2026-07-14T09:00:00Z"
}

All values above are illustrative.

References

• Cowork Audit Log
• MCP and Extensions
• Claude Desktop