a member's claude is their own binary and their own login

First half of per-user Claude. Provisioning and the privilege drop, not yet
wired to a turn — the chat gates stay up and behaviour is unchanged for
everyone. Committed unfinished on purpose so the reasoning is on the record
before the server agent runs any of it; the state is written up in
COMMS/sidecar-app-store/2026-08-11-per-user-claude-handoff.md.

THE CLAIM THAT CHANGED. docs/per-user-linux-accounts.md:226-229 says the Agent
SDK "has nowhere to put a uid", so a member's turn has to become its own
process — a change of shape rather than a flag. It is a flag:
sdk.d.ts:951 exposes spawnClaudeCodeProcess, documented for exactly this ("run
Claude Code in VMs, containers, or remote environments"), and node's spawn
already satisfies the SpawnedProcess shape it wants. So no second sidecar, no
PM2 entry, no inverted transport, and none of the registry rework a second
instance would have forced (registration is name-keyed and evicts its
namesake; the nine claude verbs resolve by capability with no selector).

THE PLATFORM NEVER RUNS AS A MEMBER. The tempting reading of "each member runs
their own Claude" is a second officer-agent under their uid, and it is wrong:
that sidecar needs POSTGRES_URL and the JWT signing secret, so a member-uid
process holding them could read every account and sign a token as the owner —
strictly more than their shell can do, and already forbidden by the .env boot
check. The harness stays the service user's; the thing that runs the member's
code and holds the member's credential is theirs. That is the pty sidecar's
shape, not a new one.

PER-MEMBER BINARY, deliberately, over one shared /usr/local/bin/claude. The
private part is the credential, not the executable — but claude updates itself,
and a root-owned binary is one a member cannot update, which turns "my agent is
a version behind" into a request to the owner. Same installer the owner's own
install uses, run as them, in their home. Idempotent by skipping when present
rather than re-running: the retry button reprovisions on every press.

ALLOWLIST, NOT A FILTER, for the child's environment. At the moment of the call
the calling process holds POSTGRES_URL, the JWT secret and the owner's
ANTHROPIC_API_KEY; setpriv --reset-env means nothing crosses unless written
into the argv, so an allowlist is the complete answer to what a turn can see,
and a denylist would have to be right about every variable added later.
NEVER_ENV throws rather than leaks if someone widens it.

Login is the member's own act against their own account. The platform cannot do
it for them and must not try — the alternative is lending them the owner's
credential. claudeLoginState only reports whether the credential has appeared,
and reads it as the member, so a true answer means their process can reach it.

NOT VERIFIED: any of it at runtime. tsgo passes; nothing has been provisioned
and the spawn hook has never been called. If it turns out setpriv breaks how
the SDK reaches the process, this approach is wrong and the fallback is the
earlier plan.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
2026-08-11 21:32:15 +00:00
co-authored by Claude Opus 5
parent 48ed171b38
commit 62e98dff2e
4 changed files with 500 additions and 2 deletions
@@ -0,0 +1,235 @@
# Handoff — per-user Claude, 2026-08-11
Branch `sidecar-app-store`, based on `48ed171`. **Three files, uncommitted at the time of writing.** This is
the start of item 4 in `2026-08-11-per-user-accounts-handoff.md` §6 ("Per-user Claude"), and it revises two
claims that handoff and `docs/per-user-linux-accounts.md` both make.
Written for the agent on the production host, to read **before** running any of it. Nothing here has been
executed against a real member account. Items 13 of the earlier handoff (bind mount, terminal replay,
`deprovisionOsAccount`) were deliberately skipped on the owner's instruction and are still open.
---
## 1. The claim that changed, and why it matters
`docs/per-user-linux-accounts.md:226-229` says `query()` from `@anthropic-ai/claude-agent-sdk` "spawns
`claude` itself and takes `env`/`cwd` but has nowhere to put a uid", concluding that dropping privileges must
happen *outside* the SDK, which makes a member's turn "its own process — a change of shape rather than a
flag."
**That is stale.** The installed SDK exposes exactly that hook:
```
node_modules/@anthropic-ai/claude-agent-sdk/sdk.d.ts:951
spawnClaudeCodeProcess?: (options: SpawnOptions) => SpawnedProcess;
sdk.d.ts:936 "Custom function to spawn the Claude Code process.
Use this to run Claude Code in VMs, containers, or remote environments."
```
`SpawnOptions` (`sdk.d.ts:2006`) supplies `{command, args, cwd, env, signal}`; `SpawnedProcess`
(`sdk.d.ts:1965`) wants `{stdin: Writable, stdout: Readable, killed, exitCode, kill(sig), on('exit'|'error')}`
— which is what `node:child_process.spawn` returns natively. So the existing sidecar can wrap the CLI spawn in
`sudo setpriv` per turn. No second sidecar, no new PM2 entry, no inverted transport.
**VERIFIED:** the type declarations above, and that `bunx tsgo` passes with an implementation written against
them. Installed SDK is **0.2.59**; `package.json:31` pins `^0.2.41`.
**NOT VERIFIED:** that the hook behaves as documented at runtime. It has never been called. If it turns out
the SDK also needs to reach the spawned process in a way `setpriv` breaks, this whole approach is wrong and
the fallback is the earlier plan (member turn as its own process).
Second stale claim, already corrected once: `docs/per-user-linux-accounts.md:230` still says a member's
`claude` "needs only `ANTHROPIC_BASE_URL` pointed at the proxy and no key of its own." The previous handoff
§5 retracted that. **Both passages need editing; neither has been edited.** Left alone deliberately so this
document is the record of what was believed when the code was written, rather than the doc silently agreeing
with the code.
---
## 2. Architecture: the platform never runs as a member
The owner's constraint, and the design follows it: **there is never a platform process running under a
member's uid.** The platform runs once as the service user and spawns everything.
This also rules out the tempting reading of "each member runs their own Claude" — a second `officer-agent`
under their uid. It does not work, for a reason worth stating because it looks like plumbing and is actually a
boundary. That sidecar needs `POSTGRES_URL` (it imports `officerdb` at `user-instance.ts:19`) and the JWT
signing secret (it mints a 30-day owner token for the MCP tools at `user-instance.ts:72`). A member-uid
process holding those could read every account's data and sign a token as the owner — strictly more than
their shell can do. `docs/per-user-linux-accounts.md:60-82` already forbids this shape: `.env` is 600 and
`assertSecretsClosed` refuses to boot with `OFFICER_OS_USERS` on while it is group- or world-readable.
So the split is:
| | runs as | holds |
|---|---|---|
| `officer-agent` (the harness) | service user | DB, JWT, MCP config, session log |
| `claude` (the member's turn) | **the member** | their binary, their `~/.claude` credential, their home |
This is the pty sidecar's established shape — one process, per-request identity, privileges dropped at the
point the member's code starts (`sidecar/pty/sessions.mjs:85-93`, `:113-125`). It is not a new pattern.
**It also avoids the registry rework.** A second sidecar would have needed one: registration is name-keyed and
a same-named sidecar evicts the incumbent (`sidecar-registry.ts:52-57`), `RegisteredSidecar` has no identity
field, and all nine claude verbs resolve by capability with no selector (`sidecar-registry.ts:275-402`).
Under the one-sidecar shape none of that has to change.
---
## 3. What is in the tree
### `src/servers/os-user-claude.ts` (new)
- `provisionClaudeCli({email, osUser})` — runs `curl -fsSL https://claude.ai/install.sh | sh` **as the
member**, via `runAs`. Same installer the owner's own install uses (`scripts/setup.sh:853`), chosen there
for auto-update support. Per-member binary rather than a shared one is the owner's explicit decision:
everything Claude-related is user-specific, and a root-owned binary is one a member cannot update.
- Idempotent by **skipping when the binary is present**, not by re-running the installer. The retry button
reprovisions on every press; re-downloading would cost a network round trip per press and would quietly move
a member off a version they had updated to.
- `claudeLoginState({email, osUser})``{installed, loggedIn}`. Login marker is
`~/.claude/.credentials.json`, **not** `~/.claude.json` (which holds settings/history and appears on first
run regardless).
- Both checks run **as the member**, not as root. A `true` then means the member's own process can reach those
files, which is what the answer gets used to promise. This deviates from the earlier handoff §6.4, which
said "detect login by reading `~/.claude` as root" — deliberately.
- Never throws; returns a result. Same posture as SSH/shell/Docker in `provisionOsAccount`.
### `src/servers/sidecar/claude/spawn-as-member.ts` (new)
The `spawnClaudeCodeProcess` implementation, built on the existing `runAsArgv` (`os-user.ts:95`) — i.e.
`sudo -n setpriv --reuid --regid --init-groups --reset-env --`.
- **Env is an allowlist, not a filter** (`ALLOWED_ENV`). At the moment of the call, the calling process's
environment contains `POSTGRES_URL`, the JWT secret and the owner's `ANTHROPIC_API_KEY`. A denylist would
have to be right about every variable that exists now and every one added later. `--reset-env` means
nothing crosses unless written into the argv (`os-user.ts:120-124`), so the allowlist is the complete
answer to "what can this turn see".
- `NEVER_ENV` throws rather than leaks if someone later widens the allowlist or the SDK starts merging its own
environment into `SpawnOptions.env`.
- Sets `HOME` and `CLAUDE_CONFIG_DIR` to the member's home explicitly. `--reset-env` already sets `HOME` from
their passwd entry, so `CLAUDE_CONFIG_DIR` is belt — but "which account's credential did this turn use"
should be answerable by reading one line.
- Uses `node:child_process`, not `Bun.spawn`: its return value satisfies `SpawnedProcess` (Bun gives web
streams and no emitter), and `Bun.spawn` silently ignores `uid`/`gid` anyway (`os-user.test.ts:23`).
### `src/servers/api/users/provision-os.ts` (modified)
`provisionClaudeCli` called after `seedShellConfig`, before `provisionRootlessDocker`. Non-fatal. Error
precedence is now ssh → claude → shell → docker.
---
## 4. What is NOT wired — read this before testing
**`spawn-as-member.ts` is never called.** `claude-manager.ts:350-352` still passes the owner's `CLAUDE_BIN`
(`:31`), `HOST_HOME` (`:35`) and `cleanEnv` (`:315`) into `query()`. The remaining work is threading a
`MemberRun` through `ClaudeSpawnStreamingParams` and the sidecar protocol so a turn carries whose it is.
**Therefore both owner gates must stay up:**
- `src/servers/api/chat/chat.ts:49-53` — HTTP refusal of non-owners
- `src/server.tsx:214-217` — chat socket refusal
Pinned by `capabilities/registry.test.ts:157-170` and `:180-185` so one cannot move without the other.
Lifting either now would run a member's turn **as the owner, with the owner's credential** — the exact
failure they exist to prevent. Do not lift them to "see if it works".
Note `chat` is already granted at `write` for every role by default (`f0af723`, seeded at bootstrap), so the
permission is live and the route refusal is the only thing standing in the way.
**Still owner-bound, untouched:**
- `api/chat/claude-sessions.ts:25``claudeHome` is a private copy of the owner-home logic; discards its
`email` whenever `HOME_DIR` is set. This is the transcript-history half.
- `api/chat/websocket.ts:51-60``resolveCwd`/`resolveBaseCwd` expand `~` against `getOwnerHomeDir`.
- `workspaces/officerdev/src/apps/ChatHistory/PwdSelector.tsx:12` — shortens with `/^\/home\/[^/]+/`, which
will not match a member's `DATA_PATH/<email>/home`. Cosmetic. The pwd picker itself is already per-caller
correct via `DirPickerModal.tsx:16``useFilesAPI('home')``rootDir`.
The pattern for all of these is `resolveHomeDir` in `src/servers/user-home.ts:34`, which already exists from
the file-browser move.
---
## 5. Verified vs assumed
**VERIFIED on the dev machine:**
- `bunx tsgo` clean across the project with all three files in place.
- `bunx prettier --write` on those three files only (not `bun format` — the tree has other uncommitted work).
- The SDK type declarations quoted in §1.
- `~/.claude/.credentials.json` exists mode 600 on a logged-in account; `~/.claude.json` exists separately.
- `CLAUDE_CONFIG_DIR` is honoured by the bundled CLI (4 occurrences in `cli.js`) and by `sdk.mjs`
(`CLAUDE_CONFIG_DIR ?? join(homedir(),'.claude')`). Zero occurrences anywhere in this repo before this
change.
**ASSUMED, NOT TESTED — the whole list:**
- That `provisionClaudeCli` succeeds for a real member. It needs network egress as the member and a writable
home. `--reset-env` means `PATH` comes from their passwd entry; if `curl` is not on that `PATH` the install
fails and the account still provisions, reporting the error.
- That the installer writes to `~/.local/bin/claude` when run under `setpriv` with a passwd-derived `HOME`.
`claudeBinPath` assumes it does. If it picks a different target the install "succeeds" and the `test -x`
gate reports failure, which is the safe direction.
- That `claudeLoginState` returns `{installed: true, loggedIn: false}` for a freshly provisioned member and
flips after they run `claude` once themselves.
- That the spawn hook works at all (§1).
- Everything about how this behaves with `DATA_PATH` at 711 with ACLs
(`docs/per-user-linux-accounts.md:392-415`). Untested for the agent's paths specifically.
---
## 6. Open questions and known risks
**Network isolation is not solved and is not in scope of this change.** A member's `claude` has general
outbound reach — it must, to authenticate — which includes loopback, where the platform's own services
listen. `docs/per-user-linux-accounts.md:221-225` already says this plainly: not a sandbox; members are
isolated from each other and from accidents, not from the host. The terminal and rootless Docker have the same
property today. If "a member cannot reach the others or the outside" is a requirement rather than an
aspiration, it is a separate stage (per-uid firewalling or a network namespace) covering all three surfaces,
and it wants looking at **on the host that actually runs members** — not on the dev box. I probed the dev box
for this and the results say nothing about the deployment; disregard any such finding from me.
**`curl … | sh` per member sits against this repo's supply-chain stance.** `bunfig.toml` sets
`frozenLockfile` precisely so nothing resolves that nobody chose, with the 2026-08-04 npm compromise as the
reasoning. This adds an unreviewed network fetch executed once per account creation. It is how the tool ships
and what the owner's own install does, and the owner accepted the trade — but it should be a conscious one,
not a thing discovered later in a diff.
**`spawn-as-member.ts` has no test.** It is the one file standing between a member's turn and the owner's
credential, and the guarantee is currently a code-read. The test to write is in the shape of
`os-user.test.ts`: assert no `NEVER_ENV` name survives into the argv `runAsArgv` produces, and that `HOME` and
`CLAUDE_CONFIG_DIR` point inside the member's home.
**Untested interaction with `claude-manager.ts`'s module-level state.** `CLAUDE_BIN` (`:31`) and `HOST_HOME`
(`:35`) are resolved once at import, from the *sidecar process's* environment. Both are wrong for a member and
both are what the wiring in §4 has to override per turn, not globally.
---
## 7. Running it
Provisioning lives in the main server, so the change takes effect with:
```
pm2 restart officer
```
`spawn-as-member.ts` is not imported by anything yet, so `officer-agent` does **not** need restarting and
restarting it proves nothing about this change.
To exercise the provisioning half on the server: press the terminal/retry icon on a member's row in
Settings → User management (`provisionOsAccount` is idempotent and will run the new step), then as root:
```bash
sudo ls -l ~<member>/.local/bin/claude # expect: present, owned by the member
sudo ls -l ~<member>/.claude/.credentials.json # expect: ABSENT until they log in themselves
```
Then have the member open a terminal and run `claude` once to log in with **their own** account. Confirm the
credential appears and that `claudeLoginState` flips. Do not log in on their behalf with the owner's account
— that is the thing this whole design exists to avoid.
Expect **no change to chat behaviour for anyone**, member or owner: the gates in §4 are still up and the
spawn hook is not called. If a member's chat starts working after this change, something is wrong.