Mounts

Asylum mounts your project, config, caches, and tools into the container. Your project is mounted at its real host path — not /workspace — so absolute paths and git worktrees work correctly.

Default Mounts

What	Host Path	Container Path	Mode
Project directory	$PWD	$PWD	Read-write
Git config	~/.gitconfig	/tmp/host_gitconfig	Read-only
SSH keys	Depends on SSH isolation	~/.ssh/	Read-only (keys), Read-write (known_hosts)
Agent config	Depends on isolation mode	Agent-specific path	Read-write
Shell history	~/.asylum/projects/<id>/history/	~/.shell_history/	Read-write
Claude temp root (Claude sessions only)	~/.asylum/projects/<id>/tmp/	Same path	Read-write
Direnv approvals	~/.local/share/direnv/allow	Same path	Read-only
.env file	$PWD/.env	Loaded as --env-file	—

Claude Code keeps its scratchpad and background task output under CLAUDE_CODE_TMPDIR, which Asylum points at the temp root. The files survive container restarts, and any path Claude prints opens unchanged on the host. Asylum never prunes the directory. asylum cleanup removes it with the rest of the project data. Other tools keep using the container's local /tmp.

Cache Volumes

Package caches are stored in named Docker volumes (not host bind mounts), scoped per project:

Cache	Container Path	Kit
npm	~/.npm	node/npm
pip	~/.cache/pip	python/uv
Maven	~/.m2	java/maven
Gradle	~/.gradle	java/gradle

Named volumes persist across container restarts and are shared between sessions on the same project.

Shadow node_modules

When the Node.js kit is active (with shadow-node-modules: true, the default), Asylum creates a named Docker volume for each node_modules directory found in the project. This isolates Linux-built native binaries from macOS host binaries.

See Node.js Kit — Shadow node_modules for details.

Git Worktrees

If the project directory is a git worktree, Asylum detects and mounts both the worktree's .git file and the main repository's .git directory. This ensures git operations work correctly inside the container.

Custom Volumes

Add extra volumes via config or CLI:

# .asylum
volumes:
  - ~/shared-data:/data:ro
  - /tmp/exchange:/tmp/exchange

asylum -v ~/data:/data:ro

Tilde (~) is expanded. Supported options: ro, rw, z, Z, shared, cached, delegated, and others.

Host IP Access

The host machine is accessible from inside the container via host.docker.internal.