Skip to content
DSH Brickbook

Events

Three books of events

Choosing the right event domain is the first decision for most changes. Keep journal facts, live intercom calls, and capability policy in the right book.

session

Session events · Journal

Facts written down and preserved across restarts.

Use when：The fact must survive a reload

  • turn/start · turn/end

    Open and close a turn

  • step/start · step/end

    One think-and-act step

  • user/message

    Input entering a step (surface)

  • assistant/chunk · assistant/message

    Live notes and clean copy

  • tool/call · tool/result

    Action and report card

  • request/header

    The frozen request envelope

  • session/event

    Broadcast every log event

agent

Agent events · Intercom

Live calls during work that do not enter the journal body.

Use when：Observe or intercept in-flight work

  • agent/inbox/*

    inserted / claimed / discarded / spliced

  • agent/status

    idle ⇄ running

  • agent/pre-step

    waterfall: reject or rewrite claimed input

  • agent/request

    waterfall: change the model, not the essay

  • agent/request-error

    waterfall: retry or let failure through

  • agent/turn-stopping

    serial: the final chance to add a note

capability

Capability events · Rules

Attach policy to a socket without entering the heartbeat room.

Use when：Add policy and adapters to a seam

  • llm/stream

    waterfall: wrap the adapter stream

  • tools/pre-execute

    allow / deny / ask

  • tools/execute

    wrap the tool function with timeouts or metrics

  • tools/post-execute

    accept / replace / block

  • fs/write-intent · fs/edit-intent

    observe before writes

  • fs/observed

    emit: synchronous bookkeeping after a read or write succeeds

  • system-prompt/assemble

    final prompt assembly

The tool pipeline

  1. 01createExecution: freeze arguments
  2. 02tools/pre-execute waterfall: allow / deny / ask
  3. 03If ask → ctx.approval
  4. 04ToolGuard[]: may only tighten policy
  5. 05tools/execute waterfall: timeout wraps tool.execute
  6. 06tools/post-execute: accept / replace / block
  7. 07finalizeContent: last model-visible edit; must not throw
  8. 08tools/result emit: freeze the report card

The four dispatch modes, once more

emit

Broadcast: listeners may observe but cannot veto.

waterfall

Call next() to pass the paper inward; otherwise you take control.

parallel

The whole class works at once, such as flushing the journal to disk.

serial

Take turns speaking, with no next(). turn-stopping uses this mode.