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hyperhive/docs/swarm/schedules.md
atlas 3464a912bf schedules: keep projecting a schedule whose definition stops decoding
A reconcile projected only the definitions this build decodes, so after
a rollback an agent's already-projected schedule whose definition a newer
build rewrote was dropped from its key within a minute and stopped
firing. The projection now keeps an agent's stored entries whose id
belongs to an unreadable definition, as they were; it never adds one to
a key that did not hold it. A deleted readable definition still leaves
every key.
2026-10-13 08:12:50 +02:00

7.9 KiB

Scheduled prompts

A scheduled prompt hands one or more agents the same text at set times: once, or every interval from a start time. Each prompt has a name, its title. The swarm keeps every prompt, and each agent it names fires it in its own container, so a fire needs neither the hive nor the swarm controller to be up at that moment, only the agent.

Operators manage them with swarmctl schedule on the swarm controller's host. Agents can't create, change or remove one. For a one-off wake an agent sets itself, it uses remind, which stays inside its container.

Managing them

# swarmctl schedule add --name standup --agent scribe --agent iris \
    --body "post the standup summary" --at 2026-10-05T09:00:00+02:00 --every 1d
added schedule kqzpmwab
kqzpmwab  "standup"  every 1d  from 2026-10-05T07:00:00Z  next 2026-10-05T07:00:00Z  agents: iris, scribe  | post the standup summary

# swarmctl schedule list
# swarmctl schedule list --agent scribe
# swarmctl schedule edit kqzpmwab --body "post the standup summary to the team room"
# swarmctl schedule edit kqzpmwab --add-agent atlas --remove-agent iris
# swarmctl schedule pause kqzpmwab
# swarmctl schedule resume kqzpmwab
# swarmctl schedule rm kqzpmwab
  • --agent names an agent to fire the prompt in; repeat it for more. Each must be an agent some hive's wanted state declares.
  • --at takes an RFC 3339 time with its offset, or unix seconds. Without it the first fire is now. A time in the past fires its latest past time once, as soon as each agent reads the prompt.
  • --every takes a count and a unit, s, m, h or d. Without it the prompt fires once.
  • schedule edit changes only the flags you pass and keeps the id. --once turns a recurring prompt into a one-shot. --add-agent and --remove-agent change who gets it; removing the last agent fails, so remove the prompt instead.
  • schedule list shows one row per prompt: id, name, cadence, start, next fire time, agents, and the first line of the body.

The full flag reference is swarmctl-cli.md.

When a prompt fires

A prompt's fire times are its start time plus whole intervals. Each agent works them out from the prompt itself, so:

  • Editing the text or the name doesn't move them. Neither does changing the agents. Only a new --at or --every does.
  • An agent that was down or disconnected fires once. When it's back, it fires the latest time it missed and then carries on at the next one. The earlier missed times don't fire.
  • A restart refires nothing. Each agent records the last time it fired for each prompt in its state database, and fires a time only when it's later than that. An agent removed from a prompt and added back keeps that record, so it doesn't refire a time it already fired.
  • A one-shot fires once, even though it stays in schedule list until you remove it. Moving its --at to a later time fires it again then.
  • A paused prompt doesn't fire, and the times that pass while it's paused don't fire when it resumes. An agent marks those times as passed while it watches the paused prompt; if the agent was down for the whole pause, it fires the latest time it missed once, as above.

A fire reaches the agent as a schedule loose end with the prompt's text. The agent's turn loop wakes for it like any other loose end. If the agent hasn't dealt with the previous fire yet, the new fire replaces it rather than adding a second one; once the agent dismissed the previous one, the next fire opens a new one.

Each agent reads its prompts every 10 seconds, so a fire can land up to 10 seconds after its time. A change reaches each agent within the same window, or within a minute if the controller's first attempt to pass it on failed.

When a prompt doesn't fire

  • The agent isn't connected to the swarm queue. It reads its prompts with its own swarm-queue credential. A harness that can't connect retries for about five minutes, then exits and comes back; it reads no prompts until a connect succeeds. See Giving the agents the queue too.
  • The agent hasn't read its prompts since it started. It fires from the last list it read; until the first read succeeds it fires nothing. A read that fails later keeps the previous list.
Implementation

swarm-controller is the only client that writes either of the two KV buckets involved.

schedule-definitions holds every prompt as one JSON document under the key all. Agents hold no grant on this bucket. Each change re-reads the key and writes against its revision, so a prompt exists for every one of its agents or for none of them, and two changes at once don't lose one. The controller leaves a prompt it can't decode, such as one a newer build wrote, out of the list, with a warning in its log. An agent's key that already held the prompt keeps it as it was, so it goes on firing, and no other key gets it. The controller keeps the prompt in the document as it was, after the others, and won't reuse its id. A document that isn't an object with a list of schedules is an error.

agent-schedules holds one key per agent: the prompts naming that agent, without their names or other agents. A key the controller can't decode counts as no prompts, with a warning in its log, and the next rewrite replaces it.

{
  "schedules": [
    {
      "id": "kqzpmwab",
      "body": "post the standup summary",
      "anchor_unix": 1791183600,
      "interval_seconds": 86400,
      "paused": false
    }
  ]
}

interval_seconds is absent for a one-shot. After each change the controller rewrites the key of every agent the change named before or after, and once a minute it rewrites every agent's key, so a rewrite that failed converges. Ids are 8 lowercase letters, the same in every agent's key, never reused, and so never equal to a hive schedule's numeric id.

swarmctl schedule calls these routes over the controller's socket:

method path body
GET /api/schedules —; answers every prompt, sorted by name then id
POST /api/schedules name, agents, body, and optional anchor_unix, interval_seconds, paused; answers 201 with the prompt
PATCH /api/schedules/<id> any of name, body, anchor_unix, interval_seconds (null for a one-shot), paused, add_agents, remove_agents
DELETE /api/schedules/<id> —; answers 204

Each prompt they answer with has id, name, agents (sorted), body, anchor_unix, interval_seconds (null for a one-shot), paused, and next_fire_unix: the next time on the prompt's grid, as of the moment the controller answers, null when paused or a one-shot whose time has passed.

An agent's own queue credential grants exactly one subject in this bucket: $JS.API.DIRECT.GET.KV_agent-schedules.$KV.agent-schedules.<agent>, the direct read of its own key. It can't read another agent's key, open or watch the bucket, or write to it. A KV watch would need a consumer, and a consumer create subject doesn't name a key, so granting one would let the agent read every key; the agent reads its key every 10 seconds instead.

The harness (hive-agent's schedule_timer) keeps the last fired time per prompt id in the schedule_fired_slots table of its state database, and pushes each fire as the todo schedule/schedule:<id> with source scheduled, reopening an acknowledged one.