# G6 Host-Bridge Callback Semantics Design

> Date: 2026-04-19
> Status: Draft
> Upstream Report: [2026-04-19-g6-host-bridge-execution-semantics-report.md](D:/data/ideaSpace/rust/sgClaw/claw-new/docs/superpowers/reports/2026-04-19-g6-host-bridge-execution-semantics-report.md)

## 1. Intent

This design defines the next bounded slice after `G6 host-bridge execution semantics`.

The target is:

`G6 host-bridge callback semantics`

## 2. Why This Slice

The previous semantic slice isolated two seams, but the tighter next pressure is callback-side semantics:

1. invocation semantics are already identified
2. callback completion semantics still determine whether later real execution can be bounded safely

## 3. Scope Boundary

This design is limited to callback semantics only.

It may include:

1. defining completion states for callback requests
2. defining blocked/error/partial/ok transitions
3. defining how callback semantics constrain later real-sample entry

It must not include:

1. implementing host-runtime directly
2. executing a `G6` real sample
3. reopening `G7`
4. opening `G8`

## 4. Target Outcome

The bounded target outcome is one state:

1. one bounded `G6 host-bridge callback semantics` plan

## 5. Exit Condition

This design is complete when implementation can be bounded to one plan that:

1. freezes callback semantics only
2. separates completion state logic from transport/runtime implementation
3. emits one bounded follow-up plan