States

States in Rind are flow condition definitions and runtime facts managed by the flow runtime. They are typed by payload, can be activated/removed, can branch into keyed instances, and can trigger other states/signals through after dependencies.

Core Definition

The base state metadata defines identity and payload type.

• name: The unique state name.
• payload: Payload type. Valid values are json, string, bytes, none.

[[state]]
name = "active"
payload = "string"

Activation on Missing Dependencies

activate-on-none auto-manages a state when dependency states are absent.

• activate-on-none: List of state names.
• The state is auto-applied when all listed states are missing/empty.
• The state is auto-removed when any listed state becomes active.

[[state]]
name = "online"
payload = "none"
activate-on-none = ["net@interface"]

Transcendent Dependencies

after declares state conditions that drive this state automatically.

• after: List of FlowItem conditions.
• Runtime behavior:
• On source apply: this state applies when all after conditions match.
• On source revert: this state reverts when the condition set is no longer satisfied.

FlowItem forms:

• Simple: "state-or-signal-name"
• Detailed: { state = "..." } or { signal = "..." }
• Detailed can include target and branch match operations.

[[state]]
name = "net-configured"
payload = "json"
after = ["net@interface"]

[[state]]
name = "session-ready"
payload = "json"
after = [
  { state = "rind@user_session", target = { as = { authenticated = true } } }
]

Branching and Payload Mapping

branch controls how JSON payloads are keyed and mapped.

• For direct set_state on JSON states:
• branch fields define identity keys for upsert/merge.
• If omitted, default key is id.
• For transcendent (after) propagation:
• branch acts as mapping specs from source payload.
• Supports target or target:source form.

[[state]]
name = "user_session"
payload = "json"
branch = ["session_id"]

[[state]]
name = "service-user"
payload = "json"
after = ["rind@user_session"]
branch = ["username:user", "uid"]

Auto Payload Generation

auto-payload generates payload when runtime needs a default/generated state payload.

• auto-payload.eval: Command to execute.
• auto-payload.args: Optional command args.
• auto-payload.insert:
• String key (single insert),
• List of keys (line-by-line mapping),
• "root" to use parsed output as root JSON.

[[state]]
name = "hostname"
payload = "json"
auto-payload = { eval = "/bin/hostname", insert = "value" }

Transport Subscribers

States can publish set/remove events to configured Transport subscribers.

• subscribers: List of TransportMethod entries.
• On bootstrap, subscriber endpoints are set up.
• On state apply/revert, type = "state" messages are sent with action set/remove.

[[state]]
name = "net-interface"
payload = "json"
subscribers = [
  { id = "uds", options = ["/run/rind/net-interface.sock"] }
]

Permission Gates

State writes through transport can be permission-gated.

• permissions: List of permission IDs (either u16 or full name to Permissions).
• Used by transport incoming handling before dispatching set_state/remove_state.

[[state]]
name = "firewall"
payload = "none"
permissions = [1001, "myperm"]

Broadcast

• broadcast: Defined on the model and accepted in TOML.
• Current flow runtime path does not consume this field yet.