Removes OpenAI Responses "chain mode" from chatd. Closes CODAGT-445.
- Deletes `chatopenai/responses.go` (chain detection, activation, prompt filtering, response ID extraction) and its tests.
- Deletes the `ChainBroken` classification in `chaterror` and the chatloop retry bookkeeping that disabled chain mode mid-generation.
- Drops the `chain_broken` label from the `coderd_chatd_stream_retries_total` metric.
- Stops reading and writing `chat_messages.provider_response_id`
- Deletes the dead `ClearChatMessageProviderResponseIDsByChatID` query. Dropping the column is a follow-up migration.
- Deletes three chatloop hooks no caller sets (`ReloadMessages`, `DisableChainMode`, `PrepareMessages`), the dead `const AgentChatContextSentinelPath`, and stale chain-mode comments.
🤖 Generated by Coder Agents on behalf of @johnstcn.
## Problem
Bedrock errors (routed through aibridge) showed the wrong provider
("Anthropic ...")
and a doubly-wrapped detail string instead of the clean message.
## Fix (chatd only)
- **Provider label:** thread the configured provider to error
classification via
`GenerateAssistantOptions.ErrorProvider`. Transport provider still
drives prompt
prep, sanitization, and metric labels (unchanged).
- **Detail:** unwrap the SDK transport wrapper (`METHOD "URL": NNN
{body}`) to surface
the inner message; handles top-level `{"message":...}` and nested
`{"error":{"message":...}}`.
## Notes
- Surfacing a top-level `message` now applies to all providers
(intentional; nested wins when both present).
- The advisor path keeps the transport label; accepted as-is (it returns
`err.Error()`, not the classification).
- Fixes display in chatd only; the wrapper originates in aibridge (out
of scope here).
🤖 Generated by Coder Agents.
Renames the Agents chat stream-silence error from `startup_timeout` to
`stream_silence_timeout` now that the timeout applies to any gap between
provider stream parts, not just first-token startup.
Updates the SDK enum, generated API docs/types, chat error copy, and
Agents UI stories/status labels so the user-facing wording describes a
stalled provider response instead of startup delay.
> **Breaking change:** This is a very minor breaking change for the
Coder Agents API: the public chat error kind enum no longer includes
`startup_timeout`, so clients matching that specific value should handle
`stream_silence_timeout` instead.
Closes CODAGT-541.
## Problem
An Agents chat stream could die with a terminal `context cancelled`
error and surface to the user as a permanent chat failure, even when no
context in our process had actually been canceled. The cancellation was
a provider-returned error value (HTTP/2 RST_STREAM mid-body surfacing as
`context.Canceled` from Go's net/http2), not a real caller cancel.
The chain that produced the bug:
- fantasy passed the provider's `context.Canceled` through unchanged.
- `chaterror.Classify` short-circuited any `errors.Is(err,
context.Canceled)` (or `"context canceled"` text) as terminal generic,
before checking HTTP status codes or other retry signals.
- `chatretry.Retry` did not retry.
- The frontend rendered `type:"error"` and the chat was dead.
The same short-circuit also masked retryable 5xx responses whose
underlying transport error happened to wrap `context.Canceled`.
## Approach
`context.Canceled` has no inherent intent. The same error value can mean
a user pressing Stop, a server shutdown, the silence guard firing, or a
provider-side stream reset. The only layer that can disambiguate is the
one holding both the returned error and the caller context. That is
`chatretry`.
This PR centralizes the policy there and keeps `chaterror` context-free.
## Changes
`coderd/x/chatd/chaterror/classify.go`
- Add `ErrProviderTransportReset` sentinel to explicitly mark
provider-side stream cancellations.
- Remove the broad `context.Canceled` / `"context canceled"`
short-circuit so status codes and other retry signals can win.
- Classify `ErrProviderTransportReset` (with no status code) as a
retryable timeout.
- Keep a fallback that classifies bare `context.Canceled` as
terminal-generic when no other signal is present, so legitimate caller
cancels still terminate cleanly.
`coderd/x/chatd/chatretry/chatretry.go`
- Add `contextError(ctx)` that returns `context.Cause(ctx)` when set,
falling back to `ctx.Err()`, so caller-owned cancel causes
(`ErrInterrupted`, `errStreamSilenceTimeout`, server shutdown sentinels)
propagate cleanly out of the retry loop.
- Add `classifyProviderAttemptError(err)` that wraps a bare
`context.Canceled` in `ErrProviderTransportReset` and reclassifies.
Errors that already classify as retryable or carry a status code are
left alone.
- Restructure `Retry` so the policy is explicit and readable: check
caller cancellation before attempting, run the attempt, check caller
cancellation again before normalizing the provider error, then classify
and retry.
## End-to-end behavior
- Provider returns `context.Canceled` while caller context is healthy:
classified as a retryable timeout, retried, the user sees a brief
`type:"retry"` event and the chat continues.
- User presses Stop: `contextError(ctx)` returns `ErrInterrupted`. Retry
stops. `chatloop` flushes partial content and persists.
- Stream-silence guard fires: `attemptCtx` is canceled with
`errStreamSilenceTimeout`, `guardedStream` produces a classified
retryable error, retry proceeds normally on the still-alive parent.
- Server shutdown: parent context's cause propagates out, retry stops.
When OpenAI's Responses API returns `Previous response with id ... not
found` for a chained turn, classify it as a `ChainBroken` retry, clear
`previous_response_id`, exit chain mode, reload full history, and let
`chatretry` retry. Self-heals chats whose anchor was poisoned before
#25074 stopped truncated streams from being persisted as a successful
turn with a stored response id.
The new state is exposed via the existing
`coderd_chatd_stream_retries_total` counter as a
`chain_broken="true"|"false"` label. Aggregating queries (`sum`, `rate`
over `provider`/`model`/`kind`) keep working without changes; raw-series
matchers without aggregation will now see two series per `(provider,
model, kind)` where they previously saw one. The metric is internal-only
so the blast radius should be small, but if you have dashboards that
index by exact label matchers without aggregation they will need an
extra `sum` or an explicit `chain_broken` selector.
> 🤖 This PR was created with the help of Coder Agents, and was reviewed by a human 🧑💻
Moves the chat error kind taxonomy from `coderd/x/chatd/chaterror` into
`codersdk.ChatErrorKind` and types `ChatError.Kind` /
`ChatStreamRetry.Kind` so generated TypeScript exposes an SDK-owned
union, including `usage_limit`. Backend chat classification now
references the SDK constants directly while preserving the existing JSON
string values.
Keeps chat usage-limit admission failures on their existing 409 response
shape. The frontend maps structured usage-limit responses to the
SDK-owned `usage_limit` kind, uses generated `TypesGen.ChatErrorKind`
directly, and removes the local string union and alias.
Adds production-observability metrics to coderd/x/chatd/ for
model-level correlation and a chatStreams memory-leak investigation.
- Label per-request chatd metrics (steps_total, message_count,
prompt_size_bytes, tool_result_size_bytes, ttft_seconds,
compaction_total) with `model` and enrich the per-turn logger
with provider/model.
- Add `coderd_chatd_stream_retries_total{provider, model, kind}`
counter incremented in chatloop before OnRetry.
- Register a prometheus.Collector exposing `streams_active`,
`stream_buffer_size_max`, `stream_buffer_events`,
`stream_subscribers` from p.chatStreams.
- Add `coderd_chatd_stream_buffer_dropped_total` counter,
incremented per publishToStream drop independently of the
existing log-rate-limited bufferDropCount.
- Snapshot logger/model before the title-generation goroutine to
avoid a data race with the logger/model rebind below it.
> 🤖
Cian Johnston