bot-bottle/CLAUDE.md

claude-bottle

What this is

claude-bottle spins up an isolated container for running Claude Code with a curated set of skills and env vars. The point is to run Claude with broad permissions inside a sandbox, so a misbehaving agent cannot reach the host. Bash scripts orchestrate the container lifecycle and the copying of skills and env vars into it.

Goals

• Minimize risk of running claude with full permissions
• Allow me to easily spin up agent tasks in parallel
• Create isolated, well defined, easily updated, shareable agents

Non-goals

• Communicating between agents directly
• Self hosted VMs (v1 uses local Docker containers, not VMs)
• Advanced agent auditing (lean on git history for auditing)

Repository layout

• README.md — short public-facing description.
• CLAUDE.md — this file, orientation for future Claude sessions.
• .gitignore — OS junk.
• claude-bottle.json — manifest of named agents (env / skills / prompt per agent), consumed by cli.sh. See "Manifest" under "Intended design".
• docs/INDEX.md — pointer to the journal and research notes.
• docs/JOURNAL.md — append-only log of decisions and state changes.
• docs/prds/ — product requirement docs.
• docs/research/ — research notes (empty for now, kept tracked via .gitkeep).
• .claude/skills/init-entry/ — project-local Claude Code skill providing /init-entry for adding journal entries. Snapshotted from ~/.claude/skills/init-entry/ at scaffold time; refresh deliberately if it drifts.

The container launcher scripts (Dockerfile, cli.sh, lib/*.sh) landed in PRD 0001 and were extended in PRD 0002 with lib/manifest.sh, lib/env_resolve.sh, and lib/skills.sh. Note: any future repo-root skills/<name>/ directory (skills sent into the container) is a distinct concept from .claude/skills/<name>/ (Claude Code skills used while working in this repo) — don't conflate them.

Conventions

• Text-driven content. docs/JOURNAL.md is an append-only stream of thought, newest first. Entries are timestamps followed by freeform prose — no templates, no required sections. Add entries with /init-entry.
• Product requirement docs live in docs/prds/.
• Research notes live in docs/research/.
• Low dependencies by default. The project is bash-first; ask before adding new tools, runtimes, or package managers.

Intended design

PRD 0002 lands the manifest-driven agent flow described below. The defaults/ directory and the repo-side skills/ snapshot/diff loop sketched at scaffold time are deferred — see "Deferred from the scaffold sketch" at the end of this section.

Manifest

Per-agent configuration lives in claude-bottle.json under an "agents" key. cli.sh looks for this file in two locations and merges them:

1. Current working directory ($PWD/claude-bottle.json) — project-local agents.
2. Home directory ($HOME/claude-bottle.json) — personal global agents.

If both exist, the two agents objects are merged (home is the base, cwd entries win on a same-agent-name conflict). If neither file exists, cli.sh dies with a clear message.

Each agent has three attributes:

• env — hash of env vars. Each value is a JSON string whose mode is selected by sentinel prefix:

  • "?<message>" — value is prompted at runtime from /dev/tty (silent), exported into the launcher process, and forwarded to the container via docker run -e NAME (no =value). Never written to disk, never on argv. The launcher always asks, even if a same-named var is already in the parent shell. <message> is rendered verbatim as the prompt body; the launcher appends (input hidden):. Bare "?" is allowed and falls back to a default claude-bottle: secret value for NAME prompt.
  • "${HOST_VAR}" — exact ${IDENT} form, where IDENT matches [A-Za-z_][A-Za-z0-9_]*. Value is read from $HOST_VAR in the host process env at launch time. Treated the same as a secret on the wire: copied into this process under the target name, forwarded as -e NAME (no =value), never written to disk.
  • any other string — literal value, hardcoded in the manifest. Written to a mode-600 env-file under mktemp -d and passed to docker via --env-file. Newlines are rejected up front because docker --env-file cannot represent them. A literal whose text starts with ? or matches ${IDENT} is not representable in v1 — pick a different value or revisit the convention.

• skills — list of skill names. Each is docker cp'd from ~/.claude/skills/<name>/ into the running container's ~/.claude/skills/<name>/, preserving per-skill directory structure (no flattening, no archives). If a referenced skill is missing on the host, cli.sh fails with a clear message naming the skill and the path checked. The host→repo fallback and host↔repo diff prompt described in the original sketch are deferred.

• prompt — string prepended to the chat when the container session boots. Delivered by writing the string to a file inside the container via docker cp (so the prompt content does not land on docker exec argv) and passing it to claude --append-system-prompt-file <path>. Note: as of the claude-code version pinned in the Dockerfile, this flag is real but is not surfaced in the alphabetized claude --help output (only mentioned obliquely under --bare); a future rename or removal will break the launcher with a clear error from claude itself. Bare start (no <name>) is intentionally not supported — <name> remains required.

• ssh — optional array of SSH host entries. Each entry is an object with five required keys:

  • Host — the Host alias written to ~/.ssh/config in the container (also the name you use as the ssh destination).
  • IdentityFile — absolute path to the private key file on the host (leading ~ is expanded). At launch the key is docker cp'd into /root/.claude-bottle-keys/ (mode 700, root-owned), loaded into a root-owned ssh-agent listening on /run/claude-bottle-agent.sock, and the key file is then deleted. The agent socket is chmod 666 so the node user can connect; the agent protocol only exposes signing operations, never the key bytes. Keys must be passphrase-less (no TTY for ssh-add to prompt against).
  • Hostname — the actual hostname or IP for HostName.
  • User — the SSH username for User.
  • Port — the SSH port number for Port.
  • KnownHostKey — (optional) the host's public key, written to ~/.ssh/known_hosts under both the Host alias and the Hostname (so the lookup succeeds whether the connection uses the alias or the raw IP/host, e.g. a git remote URL with the bare IP). Eliminates the interactive host-verification prompt on first connect.

  Per-Host blocks in ~/.ssh/config use IdentityAgent /run/claude-bottle-agent-public.sock rather than IdentityFile, so SSH always reaches the agent regardless of SSH_AUTH_SOCK. The public socket is served by a root-owned socat forwarder, not by the agent itself: OpenSSH's ssh-agent enforces a SO_PEERCRED-based UID-match check on every connection (only accepts peers with euid 0 or matching the agent's own uid), so non-root callers like node are rejected even when the socket is mode 666. socat runs as root, accepts node's connections on the public socket, and proxies to the real agent socket at /run/claude-bottle-agent.sock; from the agent's perspective the peer is uid 0 and passes the check.

  Why an in-container agent (not a bind-mounted host agent): Docker Desktop on macOS does not forward Unix-domain socket connect() across the macOS↔Linux VM boundary (returns ENOTSUP). Running the agent inside the container sidesteps that while preserving the isolation property we want (node can use the key for SSH but cannot read the bytes — root-owned agent and forwarder, no CAP_SYS_PTRACE).

  cli.sh start validates that every key file exists on the host before the y/N prompt, then after the container is running it spawns the in-container ssh-agent, loads the keys, deletes the key files, and writes ~/.ssh/config (mode 600) with one Host block per entry.

Agent keys (the top-level keys of claude-bottle.json) should already be slug-friendly (lowercase, alphanumeric + hyphens). The container name is claude-bottle-<slug>, with a numeric suffix appended on conflict — so two parallel starts of the same agent get distinct containers (claude-bottle-journal, claude-bottle-journal-2, ...) instead of the second failing. Two distinct agent keys that slug to the same value (e.g. "Review PR" and "review-pr") will both work but become hard to tell apart in docker ps; pick keys that are already slugs to avoid that ambiguity. CLAUDE_BOTTLE_CONTAINER still pins an exact name and keeps the strict-conflict failure if it's already taken.

Confirmation

Before launching a container, cli.sh shows the resolved plan and waits for a single y/N:

• agent name, image, container name
• env var names (never values; secrets are also never identified separately, since the name itself plus the manifest is the source of truth)
• skill names being sent
• prompt length and first line only

Pass --dry-run (or set CLAUDE_BOTTLE_DRY_RUN=1) to print the plan and exit before any docker run / docker cp / docker exec.

Deferred from the scaffold sketch

The pre-PRD-0002 sketch described a repo-root skills/<name>/ snapshot, a defaults/secrets.json + defaults/config.env, and a host↔repo skill diff loop. None of that is implemented; v1 reads the manifest, prompts secrets, forwards literals via --env-file, and copies host skills directly into the container. Reopen the question in the journal if and when the snapshot story matters.

When you're unsure

Ask. Default to drafting in chat over editing files when the request is ambiguous.