File-reference parts in user messages were flattened to `TextContent` at
write time because fantasy has no file-reference content type. The
frontend never saw them as structured parts.
This moves all write paths (user, assistant, tool) from fantasy envelope
format to `codersdk.ChatMessagePart`. The streaming layer (`chatloop`)
is untouched, the conversion happens at the serialization boundary in
`persistStep`.
Old rows are still readable. `ParseContent` uses a structural heuristic
(`isFantasyEnvelopeFormat`) to distinguish legacy envelopes from SDK
parts. We chose this over try/fallback because fantasy envelopes
partially unmarshal into `ChatMessagePart` (the `type` field matches)
while silently losing content. A guard test enforces that no SDK part
can produce the envelope shape.
This is forward-only: new rows are unreadable by old code. Chat is
behind a feature flag so rollback risk is contained.
Also adds a typed `ChatMessageRole` to replace raw strings and
`fantasy.MessageRole*` casts at the persistence boundary. The type
covers `ChatMessage.Role`, `ChatStreamMessagePart.Role`, the
`PublishMessagePart` callback chain, and all DB write sites.
`fantasy.MessageRole*` remains only where we build `fantasy.Message`
structs for LLM dispatch.
Separately, `ProviderMetadata` was leaking to SSE clients via
`publishMessagePart`. `StripInternal` now runs on both the SSE and REST
paths, covering this.
Other cleanup:
- Old `db2sdk.contentBlockToPart` silently dropped metadata on
text/reasoning/tool-call content. New code preserves it.
- `providerMetadataToOptions` now logs warnings instead of silently
returning nil.
- `db2sdk` shrinks from ~250 lines of parallel conversion to ~15 lines
delegating to `chatprompt.ParseContent()`, removing the `fantasy` import
entirely.
Refs #22821
## Bug
After compaction in the chat loop, the loop re-enters and calls the LLM
with a prompt that has **no non-system messages**. Anthropic (and most
providers) require at least one user/assistant/tool message, so the API
errors with empty messages.
## Root Cause
The compaction summary was stored as `role=system`. After compaction,
`GetChatMessagesForPromptByChatID` returns only:
- The compressed system summary (matched by the CTE)
- Original non-compressed system messages (system prompts)
All original user/assistant/tool messages are excluded (they predate the
summary). The compaction assistant/tool messages are `compressed=TRUE`
and don't match the main query's `compressed=FALSE` clauses.
So `ReloadMessages` returned only system messages. The Anthropic
provider moves system messages into a separate `system` field, leaving
the `messages` API field as `[]`.
## Fix
1. **Changed compaction summary from `role=system` to `role=user`** —
the summary now appears as a user message in the reloaded prompt, giving
the model valid conversational context to respond to.
2. **Simplified the CTE** — removed the `role = 'system'` check and
narrowed `visibility IN ('model', 'both')` to just `visibility =
'model'`. The summary is the only compressed message with
`visibility=model` (the assistant has `visibility=user`, the tool has
`visibility=both`), so the role check was redundant.
## Test
`PostRunCompactionReEntryIncludesUserSummary`: verifies the re-entry
prompt contains a user message (the compaction summary) after compaction
+ reload.
Split from #22693 per review feedback.
Fixes multiple bugs in coderd/chatd and sub-packages including race
conditions, transaction safety, stream buffer bounds, retry limits, and
enterprise relay improvements.
See commit message for full list.
## Problem
Three bugs with chat summarization (compaction) share a single root
cause: `ReloadMessages` was never wired up in the production
`chatloop.Run()` call.
### Bug 1: Compaction never fires between steps
The inline compaction guard in `chatloop.go` requires both `Compaction`
and `ReloadMessages` to be non-nil:
```go
if opts.Compaction != nil && opts.ReloadMessages != nil {
```
Since `ReloadMessages` was only set in tests, inline compaction was
**dead code in production**. Long multi-step turns could blow through
the context window.
### Bug 2: Compaction only occurs at end of turn
The post-run safety net doesn't check `ReloadMessages`, so it was the
only compaction path that fired:
```go
if !alreadyCompacted && opts.Compaction != nil { // no ReloadMessages check
```
This meant compaction only happened once, after the entire agent turn
finished.
### Bug 3: Agent stops after summarization
After post-run compaction, `Run()` unconditionally returned `nil`.
`processChat` then set the chat status to `waiting` (done). The agent
never had a chance to continue with its fresh summarized context.
## Fix
1. **Wire up `ReloadMessages`** in `chatd.go`: reloads persisted
messages from the database and re-applies system prompts (subagent
instruction, workspace AGENTS.md).
2. **Wrap the step loop in an outer compaction loop**: when compaction
fires on the model's final step (`compactedOnFinalStep`), reload
messages and `continue` the outer loop so the agent re-enters with
summarized context.
3. **Track `compactedOnFinalStep`** to distinguish inline compaction on
the last step (needs re-entry) from inline compaction mid-loop followed
by more tool-call steps (agent already consumed the compacted context,
no re-entry needed).
4. **Add `maxCompactionRetries = 3`** to prevent infinite compaction
loops.
## Testing
- All 7 existing compaction tests pass unchanged.
- Added `PostRunCompactionReEntersStepLoop` test: verifies that when a
text-only response triggers compaction, the outer loop re-enters and the
agent makes a second stream call with fresh context.
## Problem
Context compaction in chatd persisted durable messages for the
`chat_summarized` tool call and result via `publishMessage`, but never
published `message_part` streaming events via `publishMessagePart`. This
meant connected clients had no streaming representation of the
compaction.
The client's `streamState` (built entirely from `message_part` events in
`streamState.ts`) never saw the compaction tool call, so:
- No **"Summarizing..."** running state was shown to the user during
summary generation (which can take up to 90s).
- The durable `message` events arrived after or interleaved with the
`status: waiting` event, causing the tool to appear as "Summarized" with
the chat appearing to just stop.
## Fix
### 1. `CompactionOptions.OnStart` callback (chatloop)
Added an `OnStart` callback to `CompactionOptions`, called in
`maybeCompact` right before `generateCompactionSummary` (the slow LLM
call). This gives `chatd` a hook to publish the tool-call `message_part`
immediately when compaction begins.
### 2. Tool-result streaming part (chatd)
`persistChatContextSummary` now publishes a tool-result `message_part`
before the durable `message` events, so clients transition from
"Summarizing..." to "Summarized" before the status change arrives.
### Event ordering is now:
1. `message_part` (tool call via `OnStart`) — client shows
"Summarizing..."
2. LLM generates summary (up to 90s)
3. `message_part` (tool result) — client shows "Summarized" in stream
state
4. `message` (assistant) — durable message persisted, stream state
resets
5. `message` (tool) — durable tool result persisted
6. `status: waiting` — chat transitions to idle
## Tests
- **`OnStartFiresBeforePersist`**: Verifies callback ordering is
`on_start` → `generate` → `persist`.
- **`OnStartNotCalledBelowThreshold`**: Verifies `OnStart` is not called
when context usage is below the compaction threshold.
Mathias Fredriksson