harness

The queued row to edit (its client-visible `entry_id`).

The replacement message (string sugar or a full user/custom message).

False when no still-parked row matched — already drained or unknown.

Effective per-session boundary for shell/coder calls. `workspace` when the filesystem approval hook can widen it, otherwise `configured_roots`.

Working-directory root stamped onto the first turn of a session whose send carries no explicit `fs_scope.root`; `null` when defaulting is disabled (`default_filesystem_root: "off"`) or the cwd is unreadable.

`deliver` (default) supplies the result; `execute` releases a hook-held call through the remaining trigger pipeline.

execute only: one-shot additional roots trusted by the caller and unioned with the session's durable filesystem grants.

False when the call is unknown, already done, or (execute) not held.

True when this resolve re-enqueued the turn.

Trace/span aggregates when the engine's in-memory observability exporter is available. Usage metrics remain available when it is not.

Engine event tag (advisory; the handler re-fetches the full list).

Webhook dedupe: a repeated key returns the original `{session_id, turn_id}` and appends nothing.

The incoming message; a string is sugar for a user text message. The role must be `user` or `custom`.

Required to start a NEW session unless `options.agent` supplies a model. Steering or waking an EXISTING session may omit it — the session's last turn's model (and provider, unless overridden) is inherited, the same rule the notification inject path uses. A model declared by the selected agent profile is authoritative.

Applied when this send creates/ensures the session.

Omit to create a new session.

True when `idempotency_key` matched an earlier send.

True when folded into an in-flight turn (steering).

True when the message was queued while a step was streaming; it lands in the transcript when the stream ends.

Run the child as a directory agent profile (`directory::agents::*` id). The profile's resolved system prompt (its `extends` chain composed by the directory) becomes the child's whole identity — no shared identity underneath, only the `mode` paragraph in front — its skill filter applies when `options.skills` is omitted, its `model` slots between an explicit `model` and the parent's, and its name/icon become the display defaults. Which agent profile to name is the prompt's decision. Refused combined with `options.system_prompt`, and when the profile's `extends` chain does not resolve.

Optional display-only identity for the child session. This never affects session ids, policy, routing, or execution. On named-session reuse the existing session title and metadata are retained.

Display-only parent for the console session tree, used when there is no live parent turn (e.g. a console- or workflow-issued spawn). Writes `SessionMeta.metadata.parent_session_id` so the console nests this child; it does NOT grant policy inheritance or parent-call resolution. Ignored when the dispatcher injects a real parent link (an in-turn spawn).

Spawn into this session, creating it if it does not exist (e.g. a fork, or a pre-chosen id to filter `turn-completed` subscriptions on); default: create fresh. An in-turn spawn may reuse an EXISTING id only inside its own tree (itself, or a child it spawned) — anything else is refused as a cross-run id collision. The response reports `reused: true` on reuse.

The child's self-contained goal — its opening user message. Include every resolved required selector literally (for example `Use database db: "primary"`); the child cannot infer resources from the parent.

The named session already existed and was reused — its prior transcript and parent linkage were retained (only possible with an explicit `session_id`).

Omit to stop the current turn.

Number of expired pending calls resolved this sweep.

Return only the built-in default layer — the stored `system-prompts/default` override when one is active, else the embedded Harness default — without session, runtime, registry, or hook layers. The part's `name` states which source served it.

Whether the target was dispatched this fire.

Which gate or condition stopped it. Present iff `!delivered`.

Why. Present iff `!delivered`.