## Summary
Remove the `workspace_agent_id` column from the `chats` table and
dynamically look up the first workspace agent instead.
## Problem
When a workspace is stopped and restarted, the workspace agent gets a
new ID. The `workspace_agent_id` stored on the chat at creation time
becomes stale, making the agent unreachable. This caused chats to break
after workspace restarts.
## Solution
Instead of persisting the agent ID, dynamically look up the first agent
from the workspace's latest build via
`GetWorkspaceAgentsInLatestBuildByWorkspaceID` whenever an agent
connection is needed. The `workspace_id` on the chat remains stable
across restarts.
This behavior may be refined later (e.g., agent selection heuristics),
but picking the first agent resolves the immediate breakage.
## Changes
- **Migration 000425**: Drop `workspace_agent_id` column from `chats`
- **SQL queries**: Remove `workspace_agent_id` from `InsertChat` and
`UpdateChatWorkspace`
- **chatd.go**: `getWorkspaceConn` and `resolveInstructions` now look up
agents dynamically from workspace ID
- **chatd.go**: Remove `refreshChatWorkspaceSnapshot` (no longer needed)
- **createworkspace.go**: Stop persisting agent ID when associating
workspace with chat
- **subagent.go**: Stop passing agent ID to child chats
- **SDK/frontend**: Remove `WorkspaceAgentID` / `workspace_agent_id`
from Chat type
---------
Co-authored-by: Kyle Carberry <kylecarbs@gmail.com>
Two changes:
1. **Gate subagent tools behind `!chat.ParentChatID.Valid`** so child
agents never receive `spawn_agent`, `wait_agent`, `message_agent`, or
`close_agent`. Previously all 4 tools were given to every chat.
`spawn_agent` would fail at runtime ("delegated chats cannot create
child subagents") but the other 3 had no guard at all — meaning a child
could theoretically operate on sibling chats. Removing the tools
entirely is cleaner and saves context window.
2. **Rewrite tool descriptions to explain *when* to use them**, not just
what they do. `spawn_agent` now says to use it for clearly scoped,
independent, self-contained tasks (e.g. fixing a specific bug, writing a
single module, running a migration) and explicitly says *not* to use it
for simple operations you can handle with
`execute`/`read_file`/`write_file`. It also states that child agents
cannot spawn their own subagents. The other 3 tools get similar
guidance-oriented descriptions.
Co-authored-by: Coder <coder@users.noreply.github.com>
