hyperhive/docs/swarm/credentials.md

# Credentials: the target shape

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The swarm's credential store is bao. This page is the overview of how the swarm
treats credentials; [`credentials-reference.md`](credentials-reference.md) lists
each one: who mints it, who reads it, and how it renews, with the notes for
operating them. It describes the target, not what's on disk today; the second half of the
reference maps [the files that exist right now](credentials-reference.md#where-each-secret-lives-on-disk).

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**Store secrets stay off disk.** A process pulls a value from the store at
runtime and holds it in memory only.

**The mTLS client certificate is the only credential on disk.** Each
identity (an agent, a hive, a swarm-level service) has one. It's what logs a
principal in to the store, so you place a hive's or service's certificate by
hand. The nix option for it takes a path to the certificate, never its bytes,
because a literal in a nix expression lands in the world-readable nix store.
A hive hands each agent its certificate; the agent pulls everything else
itself.

**Each credential has a minter, a reader and a renewal story.** Who mints it, who
reads it, and whether it renews without an operator are what the
[reference table](credentials-reference.md) gives for every credential, with the
operating notes that go with them.

## Where a secret lives

A swarm generates its credentials in three different places and reads them
in a fourth, so "where does this file go" has a different answer per deployment.
This page is that answer, one row per secret.

Two rules run through all of it.

**Private key material and access tokens are paths, never values.** Every option
carrying one takes a file path (`*File`), because a literal written into a nix
expression ends up in the nix store — world-readable and permanent. No
option in this tree accepts one inline, and adding one would be a leak rather
than a convenience.

The rule is about what must stay secret, not about credentials generally.
**Public material is a value**: a certificate, or a public nkey like
the queue callout's user key, reaches every client that connects,
so the store is a perfectly good place for it.

**The generator and the reader typically live in different containers.** They share
the host's network namespace, which makes them feel co-located, but their
filesystem roots are separate. That's why delivery is a **host-side copy rather
than a bind mount**: `nixos-container` refuses to start when a bind source is
missing, and a secret minted on another container's first boot doesn't exist
yet. Binding it would make one container wait on a file that waits on a
container that starts after it.

### Topologies, by who places secrets

Read every row of the [reference tables](credentials-reference.md#where-each-secret-lives-on-disk) against one of these. This is a different cut
from the [deployment shapes](services.md#deployment-shapes) --- those
say _where services run_, these say _who is responsible for a secret
file being there_ --- the two lists don't line up one-to-one, and
neither is a renaming of the other.

| topology           | what it means                                              | who places secrets                                                         |
| ------------------ | ---------------------------------------------------------- | -------------------------------------------------------------------------- |
| **all-local**      | one host runs the swarm's shared services and its own hive | nobody — the reader itself generates each secret, or a host unit copies it |
| **swarm-managed**  | the swarm's services run on a host with `swarmctl`         | `swarmctl` writes what it owns; the rest is still generated in place       |
| **hive elsewhere** | a hive that federates with a swarm it doesn't host         | the operator provides the file and names it in config                      |

## Swarm-level secrets

The rows are in the [reference](credentials-reference.md#swarm-level--one-of-each-per-swarm).

Nothing outside authelia's container reads its keys (session, JWT, storage encryption,
OIDC HMAC and the OIDC issuer), which is why no delivery step exists for them. **That's the
test worth applying to any secret added here** — and the client secret's plaintext half is
the one row that fails it, which is the entire reason a delivery step exists.

The store still holds those five keys, at `swarm/services/swarm-authelia/keys/<name>`,
so that losing the host doesn't lose them. `authelia-swarm-secrets` in the container reads
each with the secret publisher's identity and writes it to the file authelia loads. A store
with no value takes the file's, so the key keeps its value; the unit mints a new key only when
there is neither. Nothing rotates a key: the storage-encryption key encrypts authelia's
database, and a new issuer key invalidates every token issued. A container without the
publisher's identity generates the files as before.

The same unit mints the client secrets, straight into the store. It reads
`swarm/hives/<hive>/oidc/client` or `swarm/services/<client id>/oidc/client` first, and
only when the store answers and holds none does it run `authelia crypto hash generate`,
create the leaf and write the digest. Authelia keeps only the digest on disk, in
`oidc-clients/<id>.digest`, and starts from it while the store is down. A store that
can't answer a read never mints, because a second secret would rotate the first. A client with
a secret in the store but no digest, or a plaintext file but no digest, stops the unit
with exit status 3 and an `err` line naming the client; restore the digest, or delete the
leaf to mint again. `swarm-authelia-bridge` fetches its own secret from
`swarm/services/swarm-authelia-bridge/oidc/client` into
`/run/swarm-authelia-bridge/client-secret` before each start, and a store that doesn't
answer keeps the bridge down while it retries. A container without the publisher's
identity keeps the plaintext in `oidc-clients/<id>.secret`, as before.

`authelia-swarm-client-secrets` moves the `oidc-clients/<id>.secret` files an earlier
release left. For each, it stores the file's value when the store holds none, reads it
back, and removes the file only when the store holds the same value; it logs one line per
client containing `removed the file`. A store that holds a different value keeps both and
logs an `err` line, and a store that doesn't answer keeps the file and retries. Once no
file remains the unit does nothing. A file for a client that's no longer registered stays
in place, with a log line.

Three telemetry collectors exist, and each one fails that test: each reads its
own secret out of the store, under its own identity.

The **hive's** collector authenticates to the swarm's collector as its own hive,
so it reads its secret as the hive: `swarm-bao-hive-otel-oidc.service` fetches
`swarm/hives/<hive>/oidc/client` under the hive's own leaf
(`deploy.bao.clientCertFile`), on every topology, into `/run/hive-otel-oidc` on
the host's tmpfs. The file never reaches persistent disk and a reboot fetches
it again; until the store answers, the collector runs on an empty file and the
swarm refuses its exports. A hive with no leaf has no
default, and the build stops at the collector's identity assertion unless
`services.hyperhive.otel.clientSecretFile` names a file delivered some other way.

The **swarm's** collector reads its own under a leaf of its own, the fourth
store reader — the same shape as Grafana's, described in full below. In short:
`swarm-bao-otel-oidc.service` reads `swarm/services/<client-id>/oidc/client`
out of the store on every host that runs the collector and holds a store
identity, whether authelia is a network away or in the container next door.
The same call `glue-grafana-oidc-client.nix` makes for Grafana's registers
the client it reads for unconditionally: authelia refuses a
bearer-authz client with no audience, and every host publishes at least
forgejo's `/metrics` as a scrape target, so the audience is never empty.

⚠️ **A collector with no store identity isn't refused.** Unlike Grafana,
where an absent OIDC block is a container with no way in at all, a collector
with nothing to authenticate with still receives every hive's telemetry —
its pushes to the stores go out unauthenticated and get refused there, and its
scrape jobs for the published targets read a credential file nothing
loads, so they can't get a token. `swarm-bao-otel-oidc.service` therefore doesn't render at all without
`deploy.bao.otelOidcClientCertFile` / `otelOidcClientKeyFile`, rather than the hard assertion
`swarm-grafana.nix` uses for its non-optional one. The operator can still deliver the secret by
hand, at `services.hyperhive.deploy.swarm-otel.clientSecretFile`, on a
collector this unit never reaches.

The **secret store's own** collector — the forwarder inside the `swarm-bao`
container — needs a delivery step too, and it takes the same route with one
principal of its own: `swarm-bao-forwarder-oidc.service` reads
`swarm/services/<client-id>/oidc/client` under a leaf of its own and
writes it to `/run/swarm-bao-forwarder-oidc` on the host's tmpfs, which the container bind-mounts read-only and where `LoadCredential` hands it to the
collector. The client id is its own
(`services.hyperhive.swarm.bao.otel.clientId`), registered by
`glue-swarm-bao-otel-oidc-client.nix` wherever authelia runs, and the swarm
collector admits it on a receiver of its own — one identity per principal, so
this forwarder borrows neither the swarm collector's client nor
`swarm-controller`'s.

⚠️ **This one has no degraded mode, and the difference is structural.** The
route it exports over accepts an authenticated request and nothing else, so a
forwarder without the secret has nothing to fall back to: the unit fails and
retries, and the collector refuses to start until the file arrives, after every boot, rather than
exporting into a 401 while reporting healthy. Its ordering differs from the
unit above it for the same structural reason — it reads the store inside the
container it delivers into, so it runs **after** that container rather than
before it. The fetch creates the file, so when the store stays sealed or unreachable after a boot the forwarder stays down, then resumes from its saved journal cursor once the store answers.

### The queue's callout nkeys

The responder holds two nkeys besides the callout xkey below. It signs every
user JWT it issues with the **issuer** key, an account key, so possession of
the issuer seed is the authority to admit anyone to the queue. It connects to
the queue as the **user** key, the one identity the server exempts from
callout. You configure nothing about either: both live in the swarm secret
store beside the xkey, and come into being on the queue's first boot.

- **Issuer seed** at `secret/swarm/services/swarm-nats/callout/issuer-seed`,
  **public half** at `secret/swarm/public/swarm-nats/callout-issuer`.
- **User seed** at `secret/swarm/services/swarm-nats/callout/user-seed`,
  **public half** at `secret/swarm/public/swarm-nats/callout-user`.

The unit that creates the xkey creates these too, under the same rules: only
the `swarm-nats-auth` role reads or creates them, nothing replaces a stored
seed, and the policy of `swarm-secret-publisher` denies it both seed paths.
The server renders both public halves into its `auth_callout` block as it
starts, and doesn't start without them.

A seed file at `/var/lib/swarm-nats-callout/issuer.seed` or
`/var/lib/swarm-nats-callout/callout-user.seed` on the queue's host is what
`swarm-nats-auth ensure-callout-keys` stores for that key when the store holds
none, so the key keeps its public half. Once a read of the store returns a
seed, the verb removes the file. When the store already holds a different
seed, the verb keeps the store's seed, logs a warning naming the file, then
removes it.

A hive that sets `autoGenerateCallout`, `calloutUserPublicKey`,
`calloutIssuerPublicKey`, `calloutUserSeedFile` or `calloutIssuerSeedFile`,
under `deploy.nats` or `swarm.nats`, fails at eval with a message naming the
option and where the keys live now.

To replace either key, delete both of its paths the way the xkey's section
below shows for the xkey, then restart `swarm-bao-nats-callout-xkey`.

One consequence worth knowing before you debug it: the queue assembles its
config each time the server starts rather than at build time, in every mode,
because the callout keys exist only at runtime. A malformed config
surfaces when the server starts instead of when the system builds. The server
names the offending file and refuses to run.

### The queue's callout xkey

The server seals every auth-callout request to a curve key, the callout
xkey, and the responder seals its reply back, so nothing else in the callout
account or on the wire can read the request or the user JWT minted for it.
You configure nothing about the key: it lives in the swarm secret store and
comes into being on the queue's first boot.

- **Seed** at `secret/swarm/services/swarm-nats/callout/xkey-seed`.
- **Public half** at `secret/swarm/public/swarm-nats/callout-xkey`.

Only the `swarm-nats-auth` role reads either path, and it may create each but
never replace it. The policy of `swarm-secret-publisher`, which writes the rest
of `swarm/services/`, denies it the seed's path.

On the queue's host, `swarm-bao-nats-callout-xkey` runs before the
`swarm-nats` container, under the responder's store leaf:

1. `swarm-nats-auth ensure-callout-keys` creates the pair when the store holds no
   seed, and otherwise only reads it. It needs no queue, so on a first boot
   the key exists before the server that needs it.
2. It reads the public half back from the store into
   `/var/lib/nats-callout/callout-xkey.pub` inside the container.
3. Each time `nats-server` starts, it renders that key into
   `auth_callout.xkey`. With no file, the server doesn't start.
4. The responder starts after the server and reads the seed from the store.
   A responder that can't read it doesn't start, rather than answering
   requests it can't open.

The store has to be reachable each time the responder starts. When it's down,
the fetch unit fails and retries for a day. The server starts with the key
fetched last time, or not at all on a first boot. A responder that starts
while the store is down exits and retries every 5 seconds, and until one
start reads the seed the queue refuses every client, OIDC ones included. The
retry that lands the file starts or restarts the server, and the responder
comes up with it.

The responder's store leaf is `deploy.nats.authBaoClientCertFile` /
`authBaoClientKeyFile`. On the store's host both default to the leaf
`glue-bao-tls.nix` mints there. A queue host without the store gets no
default, even when it holds the hive's own reader `deploy.bao.clientCertFile`:
issue a leaf whose subject is `deploy.bao.natsAuthCommonName`, place it, and
name it in both options. Until you do, evaluation fails naming both.

Where the queue and the store run on different hosts, deploy the store's host
first. `swarm-bao-nats-auth-policy` there writes the role's grants on the
keys' paths, and `swarm-bao-secret-publisher-policy` the publisher's denial of
the seeds' paths; where the queue runs on that host too, the fetch waits for
both. A queue host deployed before it can't read or create the keys, so its
fetch fails, and the queue refuses every client until you deploy the store's
host: the server starts only on public keys fetched before, and the responder
can't load its seeds. Seed files the import is waiting for stay where they
are. If that takes longer than the fetch's day of retries, run
`systemctl restart swarm-bao-nats-callout-xkey` on the queue's host.

Two starts that create the key at once can't both win: each write is a
create that fails once the path holds anything, and the start that lost reads
the winner's key back.

To replace the key, remove both paths with their metadata and every version,
then restart the fetch unit on the queue's host. Its restart of `nats.service`
restarts the responder too, which then loads the new seed:

```sh
bao kv metadata delete secret/swarm/services/swarm-nats/callout/xkey-seed
bao kv metadata delete secret/swarm/public/swarm-nats/callout-xkey
systemctl restart swarm-bao-nats-callout-xkey
```

`bao kv delete` isn't enough. It deletes the latest version but keeps the
path's metadata, so the store still counts the path as existing and refuses
the create that makes a new key. No principal hyperhive configures may
delete either path's metadata, so run the two deletes with a token that may,
such as the root token.

## Hive-level secrets

The rows are in the [reference](credentials-reference.md#hive-level--one-of-each-per-hive).

The forge and the homeserver read their copies out of the store, the way
Grafana does below: the forge under the forge publisher's leaf, the
homeserver under matrix-ctl's. Each **fails loudly** and retries until the
mint in authelia's container has stored the secret, rather than skipping.
A silent skip produces a service whose login button always fails, which is a
symptom many layers from its cause.

The store's **first reader** is Grafana's OIDC client secret, a _swarm
service's_ own credential rather than a hive's. It has exactly
one delivery route: `swarm-bao-grafana-oidc.service` reads
`swarm/services/<client-id>/oidc/client` out of the store, on **every** host
that runs Grafana. Where authelia is doesn't enter into it — the mint in
authelia's container writes that path whether the reader is a network away or in the
container next door.

That's a deliberate refusal of the shortcut. Copying the plaintext
straight out of authelia's tree when the two happen to share a host is one
round trip cheaper and costs a second delivery unit, a second way for the file
to be wrong, and a gate deciding between them — and the gate is the expensive
part, because whatever it's wrong about is an outage nobody can read. The store
exists so the only secrets a host holds out of band are **certificates**, and
a host reads everything else with them.

Two things follow, and `swarm-grafana.nix` asserts both rather than degrading:
running Grafana requires `swarm.authelia.url` (this module disables its local
login form unconditionally, so SSO isn't a feature of some topologies — it's the
only way into the UI), and it requires this host's `deploy.bao.grafanaOidcClientCertFile`
/ `grafanaOidcClientKeyFile`. Each refusal names the option to set. Both used to be silent:
a null URL dropped the OIDC block, a missing leaf produced a warning, and
either one left a Grafana with no SSO and no password box — nothing failed, so
nothing said anything. Registration is separate and stays where authelia is
(`glue-grafana-oidc-client.nix`): a client is a row in authelia's own config,
so it's declared on the host running authelia, which isn't necessarily the host
running Grafana. The swarm controller, the queue, the homeserver and the forge
register the same way (`glue-controller-oidc-client.nix`,
`glue-nats-oidc-client.nix`, `glue-matrix-oidc-client.nix`,
`glue-forge-oidc-client.nix`), and the queue's responder, the homeserver and the
forge read their secrets from the store too: the responder itself under its own
leaf, `swarm-bao-matrix-oidc.service` under matrix-ctl's,
`swarm-bao-forge-oidc.service` under the forge publisher's. Each fails, naming
the option pair, when that leaf is unset — neither the responder nor the
homeserver starts without its secret, and the forge registers no login source
without its.

Grafana's admin password rides the same leaf and the same store. Where Grafana
and the store run on different hosts, deploy the store's host first:
`swarm-bao-grafana-oidc-policy` there writes the grant that lets Grafana create
the password, and until it has, the store refuses `swarm-bao-grafana-admin` on
the Grafana host, which retries, while Grafana stays down because its config
reads that file.

The **second reader** is the swarm collector's own OIDC client secret, the
same shape one level down: `swarm-bao-otel-oidc.service` reads
`swarm/services/<client-id>/oidc/client` out of the store on every host that
runs the collector, and registration lives separately in
`glue-swarm-otel-oidc-client.nix` for the same reason Grafana's does. Where it
differs is what an absent credential means: the collector still receives
telemetry with none, so `swarm-otel.nix` doesn't assert
`deploy.bao.otelOidcClientCertFile` / `otelOidcClientKeyFile` the way Grafana
does — it
doesn't render the reading unit without them.

The **third reader** is the secret store forwarder's OIDC client secret:
`swarm-bao-forwarder-oidc.service`, on the store's own host, registered by
`glue-swarm-bao-otel-oidc-client.nix` on authelia's. It differs from the
second in both directions. It renders unconditionally, because the export it
authenticates has no unauthenticated mode to degrade into — and it orders
itself **after** `container@swarm-bao`, because the store it reads runs in the
container it delivers into. Nothing circular sits behind that: the identity it
logs in with is the static `forwarder-oidc.pem` leaf `swarm-bao-pki` signs, not
anything the store mints. With no leaf it has no fallback, so `swarm-bao.nix`
refuses the build and names `deploy.bao.forwarderOidcClientCertFile` /
`forwarderOidcClientKeyFile`.

A service's secret is one value for the whole swarm rather than one per hive, so
it lives under the `services` prefix, and a hive's read policy grants that prefix
whole. That's because nothing in a swarm's configuration records which hive runs
a given service — placement is a `deploy.*` fact, per-host by definition — so
there is nothing to scope the grant to. A hive's **own** leaf can therefore read
every swarm service's client secret, and that's stated in
`swarm-secret-client`'s `policy` module beside the grant itself.

⚠️ **The readers no longer present it.** Five units used to log in with
`deploy.bao.clientCertFile`, which is the hive's own leaf, and bao identifies a
principal by the subject of the certificate it presents — so five readers behind
one leaf were one principal holding the union of their needs. Each now holds a
leaf of its own, and a policy naming only the path that unit reads. See
[per-principal identities](#per-principal-identities) below.

Absence behaves
as it does for the other readers: a store that says "not here" leaves the
file alone and says so, since there is no such thing as a locally valid OIDC
client secret to stand in.

⚠️ **Service↔store mTLS is its own trust domain.** You can't fetch a
credential you must already hold to authenticate from the thing it
authenticates you to, so the store's identity can't come from an authority the store
distributes — which excludes the store's `pki` root, and has nothing to do
with the gateway's HTTPS certificates either way. `glue-bao-tls.nix`
mints a CA that signs a fixed, short list of leaves — the store's server
certificate, the hive's own reader certificate, and one per service principal —
and distributes nothing. A deployment with a real
internal CA deletes that file and names its own paths in
`deploy.bao.serverCertFile` / `clientCaFile`; the store itself has no opinion.
A hive that reads from a store on **another** machine names the reader's half —
`clientCertFile`, `clientKeyFile`, `serverCaFile` — and places that leaf by hand,
plus one leaf per principal it runs (the [table in the reference](credentials-reference.md#store-identities-one-per-principal) names the options). Those are the
credentials that can't come out of the store, being what opens it; everything
else a hive needs does.

Agents are the one principal whose leaf the store issues. Its `pki-agents`
mount (`deploy.bao.agentPkiMountPath`) holds an agent CA generated inside the
store, and `swarm-controller`, already logged in under its own host leaf, asks
that mount's one role for a `hive-agent-<agent>` client certificate at agent
creation. Host roles never pin that CA and agent roles pin only it, so an
agent's certificate opens that agent's own `swarm/agents/<agent>/*` and
nothing else: `read` on the values there and `list` on their names, and `create` (never `update`) on one leaf, `backend-env`, which the agent seeds from its environment file.

All agents share one policy, `hive-agent`, which the agent's cert-auth role
attaches and no other. It states the rule with `{{identity.entity.name}}`
where an agent's name would go, so the rule is one document and a change to it
is one write. `swarm-controller` writes it at agent creation and at its own
start.

For that the controller names each agent's identity entity after the agent: at
each certificate mint or renewal, before it writes the agent's cert-auth role,
and for every agent at its own start. It reads the cert mount's accessor and
creates the entity `<agent>` with the alias `hive-agent-<agent>`, or renames the
entity a first login created under a generated name. At a mint or renewal this is
a precondition: when the store refuses a call, or the alias sits on any other
entity, the mint fails and the role stays as it was, so a live agent keeps
working until an operator resolves it. The start pass only logs the same
failures, because it writes no role. The controller needs the `identity/` and
`sys/auth/cert` grants in `swarm-bao.nix`'s `controllerPolicyText` for that.

A cert-auth role that predates the shared policy may still name a policy
`hive-agent-<agent>`. The controller no longer writes or attaches these. The
objects stay in the store and keep granting what they did, to a token that
already carries them and to a role not yet rewritten. A live agent's role is
rewritten at its next certificate renewal.

A hive's cert-auth role `hive-<hive>` attaches one policy, `hive-hives`, shared
by all hives. A hive's certificate carries its bare name as
the common name, which is the login's alias name, so hives need no entity:
the policy states the hive's own path as
`swarm/hives/{{identity.entity.aliases.<accessor>.name}}/*`, where `<accessor>`
is the cert mount's accessor. The controller reads the accessor at its own start,
writes the policy, and rewrites the roles to attach it. No hive name can
spell `hive-hives`: it would be a hive called `hives`, and
`reserved-hive-fragments.nix` refuses the substring `hive`. When the controller
can't read the accessor or write the policy it logs a warning and leaves the
roles untouched, so a role that names a `hive-<hive>` policy keeps it.

### Per-principal identities

Bao matches a cert-auth role on the certificate's subject, so a certificate is an
identity and sharing one merges the identities. The leaves, their option names
and what each reaches are in the [reference](credentials-reference.md#store-identities-one-per-principal).

Each reaches a path that names a swarm service rather than a hive, so one role
each is enough and their subjects are the flat
`deploy.bao.grafanaOidcCommonName`, `deploy.bao.otelOidcCommonName`,
`deploy.bao.forwarderOidcCommonName`, `deploy.bao.ciRunnerCommonName`,
`deploy.bao.reviewClassifierCommonName`, `deploy.bao.builderCommonName`,
`deploy.bao.ciMetricsCommonName`, `deploy.bao.atticCommonName`,
`deploy.bao.claudeLoginCommonName` and `deploy.bao.forgePublisherCommonName`.
The last three are the writers, and the last is the one leaf two units share:
the forge's host holds one store identity for the token it publishes and the
OIDC client secret it reads.

On a host that mints its own PKI, `glue-bao-tls.nix` signs all ten and defaults
all twenty options, and there is nothing to do. Elsewhere you copy each leaf from
the store's host and name it here: a service principal's from the top of
`/var/lib/swarm-bao-pki/`, another hive's leaves from
`/var/lib/swarm-bao-pki/hives/<hive>/` ([bao.md § TLS](bao.md#tls) lists that
directory). That's one file per principal rather than one file
shared by ten, which is the whole of what this buys. `swarm-ci-runner.nix`
refuses the build wherever the runner runs without its pair, as
`swarm-review-classifier.nix` does for the classifier, `swarm-ci-metrics.nix`
for the CI run poller and `swarm-grafana.nix` for Grafana. The forge's pair refuses nothing: without
it `forgejo-swarm-controller-account` and `swarm-bao-forge-oidc` render, fail at start
naming both options, and the controller runs without forge access and the forge
without a login source until an operator places the leaf.

On a host without the store, where the forwarder never runs, forgetting one of
the others isn't a quiet degrade. A hand-configured remote-store hive that
names the hive's own `clientCertFile` and misses a principal's pair has the
build refused, by the module of the reader it missed, naming that pair — see
[what a missing leaf costs](#what-a-missing-leaf-costs) below.

The roles of `swarm-nats-auth`, `swarm-logs-auth` and `swarm-metrics-auth` issue
batch tokens with a five-minute TTL (`token_type=batch`, `token_ttl=5m`). The
responders log in on every check, and the store keeps no record of a batch token,
so unauthenticated requests don't grow its token storage. Nothing can renew
or revoke a batch token.

The other roles issue service tokens that live an hour (`token_ttl=1h` and
`token_max_ttl=1h`). That covers the roles `swarm-bao.nix` writes, and the
agent and hive roles the controller writes through
`SecretStore::write_cert_role`, which takes the same value from
`CERT_ROLE_TOKEN_TTL`. The store keeps a lease for every token until it
expires, and the mount default of 32 days leaves one lease per login for a
month; at the 17 thousand logins a day this swarm made, that came to half a
million leases. A reader logs in per operation and holds the token for seconds.
The longest hold is the controller's forge work, which stops after two minutes.
A client that keeps a `SecretStore` handle longer than an hour must log in
again, because nothing renews the token. A role the controller writes takes the
TTL at its next write: a hive's at the controller's start, an agent's at its
next certificate mint or renewal. At its start the controller also reads every
existing `hive-agent-*` role and, for one whose `token_ttl` or `token_max_ttl`
differs from the TTL, writes those two fields and no others. The store keeps the
fields a write leaves out, so the role's certificate, allowed names and
policies stay. A role already at the TTL isn't written. The start logs one line
with `rewritten`, `already_current` and `failed` counts, and a role that fails
gets a warning that names it, then the pass moves on. Tokens issued before
expire on their own; the controller revokes nothing. At that rate an hour keeps
about 700 tokens live.

The granter's role keeps 15 minutes. Only the one-time bootstrap token writes
it, and a deployed store never rewrites it, so the longer TTL would not reach
it; the granter logs in and finishes within seconds.

### What a missing leaf costs

Each of the four modules asserts its own pair, on the same condition: **this host
already reads the store** — it holds `deploy.bao.clientCertFile` and
`clientKeyFile` — **and the consumer is on, and this principal's pair is null**.
The refusal names the two options, so an operator acts on the message without
opening the nix.

That condition fires on exactly one shape, the hand-configured remote-store hive
that named the hive's own pair and missed a principal's. It stays silent everywhere else, and each half of
that matters on its own:

- **A host with no store identity at all** holds no `clientCertFile` either, so
  the first clause is false. That's the supported no-store deployment, and also
  the one an operator passes through while bringing a hive up — neither should
  fail to evaluate.
- **A host that runs the store** gets every pair from `glue-bao-tls.nix` as
  defaults, so the third clause is false. Nothing to set, nothing to refuse.
- **A consumer that's off** — no collector, no Grafana — has no
  unit to skip, so the second clause is false.

The collector keeps a separate degrade underneath this, unchanged: a host with no
store identity runs a collector with no OIDC client secret and still receives
telemetry. The assertion doesn't touch that shape, because that host has no
`clientCertFile` either.

## How a reader reaches the store

Every reader dials the same URL — `https://bao.<swarm domain>:<port>` — and on
the host that runs the store that name resolves twice. `/etc/hosts` answers a
host-side unit with loopback, where openbao binds; the hive's dnsmasq answers a
container with the bridge IP, where nginx holds the same port. One `BAO_ADDR`,
and the network namespace that asked decides which half of it answers.

The container's half goes through nginx and **still doesn't terminate TLS**. It
is an nginx `stream` server with `ssl_preread on`: it reads the SNI off the
ClientHello and splices the rest of the connection through byte for byte, so
openbao completes the handshake itself. A vhost would decrypt here instead, and
the client certificate — the store's whole authentication — would stop at nginx,
leaving openbao seeing one client for every hive in the swarm. That's why the
store has no vhost and gets a passthrough: not an exception to the no-vhost
rule, the one shape that keeps it.

The stream listener binds the bridge IP rather than every address, because
openbao already holds loopback on that port in the same network namespace and a
wildcard bind would fail with `EADDRINUSE` — taking nginx, and with it every
hive domain behind the gateway, down. `network.exposeHostPorts` opens the port
on the bridge firewall and nowhere else.

Reaching the port grants nothing by itself: openbao answers nothing without a
client certificate signed by `deploy.bao.clientCaFile` or by the store's own
agent CA. The listener reads both from `listener-client-ca.pem`, which no
cert-auth role pins. The passthrough carries
whichever certificate the reader presents, unchanged.

## The browser UI

OpenBao's built-in web UI is at `https://bao-ui.<swarm domain>/`
(`swarm.bao.ui.domain`), for members of authelia's `admins` group only. Log in
with the **OIDC** tab, or with a bao token under **Other**. The gateway vhost
checks the session with authelia and proxies to an nginx inside the store's
container on
`127.0.0.1:<deploy.bao.uiProxyPort>`. That nginx forwards `/ui/` and `/v1/` to
a second openbao listener on `127.0.0.1:<deploy.bao.uiPort>`, answers 403 on
the unseal, seal, step-down, rekey and generate-root endpoints, and 404 on
everything else. ⚠️ That listener asks for **no client certificate**, because
a browser has none to present, so on this one door a bao token is the whole
credential. Anything on the store's host that can dial loopback, and any
`admins` session through the vhost, needs only a token to use the API. Unseal
from the host's `bao` CLI; the UI's unseal form gets a 403. On a self-signed
gateway where the UI is the only swarm name its host fronts, that host's nginx
doesn't wait for the store: it serves the hive leaf, or on a host that runs no
hive a throwaway self-signed certificate, on the UI's name (a browser warning)
until the unsealed store issues the services leaf, so the
stream passthrough readers use on that host comes up with the store sealed.

### OIDC login

The OIDC tab logs in through authelia as the client `swarm-bao-ui`
(`swarm.bao.ui.oidc.clientId`). An `admins` member gets a token under
`swarm-operator-viewer`: `list` and `read` on `secret/metadata/*`, and
`create` and `update` on
`secret/data/swarm/services/review-classifier/anthropic-api-key`,
`secret/data/swarm/services/review-classifier/acp-provider` and the cache's five
leaves under `secret/data/swarm/services/attic/` (`push-token`, `pull-token`,
`url`, `cache` and `public-key`). That shows the key tree and each key's
versions and timestamps, and no value: the store refuses every `secret/data/`
read. The writes are the leaves the operator fills in by hand: the review
classifier's keys, and the cache's tokens and facts, which configure an external
cache or replace the in-swarm cache's own. The cache's host units create those
leaves only while the store holds none, so a saved value survives their next run
and every deploy. The cache's signing key, `attic/jwt-secret`, isn't writable here.
Anything more needs a token.

To replace one of the cache's leaves in the UI, open `secret` > `swarm` >
`services` > `attic`, pick the leaf and choose **Create new version**. The
form starts empty because the login can't read the current value: type the
key `value` and the new value, and save. A new version replaces the whole
secret, so `value` is the only key to enter. `bao kv put` with the same login
works too.

| piece                                                                               | written by                                                                                       |
| ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| authelia client, with redirect `swarm.bao.ui.oidc.redirectUri`                      | `glue-bao-ui-oidc-client.nix`, wherever authelia runs                                            |
| its secret at `swarm/services/swarm-bao-ui/oidc/client`                             | authelia's mint, like every other service's                                                      |
| the `oidc` auth mount                                                               | `swarm-bao-granter-role`, with the bootstrap token                                               |
| `swarm-operator-viewer` policy, the mount's config and role `swarm-operator-viewer` | `swarm-bao-operator-viewer-policy`, as the granter, which reads the secret above into the config |

The granter holds no `sys/auth`, so enabling the mount stays a bootstrap-token
step. A store set up before the mount existed needs the
[one-time granter step](../getting-started/setup.md) again: it re-writes
`bao-bootstrap`, which covers `sys/auth/oidc`, and the granter's own
policy, which covers `auth/oidc/`. Until then
`swarm-bao-operator-viewer-policy` writes the viewer policy, logs the step, and
exits 0, and the UI offers token login only. `swarm-bao-granter-role` re-runs
it each time the step succeeds, so OIDC login needs no further restart.

## The constraint that decides where the root lives

The store issues a hive's gateway leaf through a role whose `allowed_domains` is
that hive's domain and `*.` that domain, and **a swarm service name is a sibling of
the hive domain rather than a child** — `forge.<swarm>` next to `<hive>.<swarm>`.
That role can't issue a certificate for a swarm service; the store refuses it.

The store's `swarm-services` role issues them instead, from the root inside its
`pki` mount. That root's private key never leaves the mount, and its
certificate is the only anchor the swarm has. Each hive fetches the certificate
from the store at boot, so nothing build-time can name it — the system reads
`security.pki.certificateFiles`' value at build time, which makes it the wrong
tool here. Host containers get a bind-mounted bundle assembled at boot; an
agent fetches the root itself with its own store certificate.

## Adding a secret

State three things, in the row you add to the [reference](credentials-reference.md#where-each-secret-lives-on-disk): **who mints it**, **which
container reads it**, and **what happens when they differ**. If they differ, it
needs a delivery unit, and the unit copies — it doesn't bind.