closes CODAGT-839
closes CODAGT-843
closes CODAGT-773
## Summary
Adds a new heartbeat usage event type, `hb_agent_runtime_v1`, measuring
the total agent-loop runtime of Coder Agents (chats) per UTC hour, plus
a reconciler that generates one event per hour with self-healing
backfill over a trailing 7-day window. Events flow to Tallyman through
the existing publisher unchanged. This measures the new Coder Agents
(the `chats` tables), not the deprecated Tasks counted by
`dc_managed_agents_v1`.
Independent of #27508, which fixes the dead ai-seats cron registration.
Both PRs carry the identical `usage_event` create permission hunk for
the usage-publisher subject (this feature's generator and the ai-seats
cron each need it for heartbeat inserts), so they can land in either
order and the overlap merges cleanly.
> [!WARNING]
> **Do not include this in a release until Tallyman accepts
`hb_agent_runtime_v1`.** The publisher marks permanently rejected events
as done-forever, and the generator then sees those buckets as complete
locally, so their usage would be silently and permanently lost.
## Details
Each event's payload is `{"runtime_ms": N}`: the sum of
`chat_messages.runtime_ms` for messages created in the hour bucket `[H,
H+1)`, across all chats (sub-agents, API-created, archived, and
soft-deleted messages included). Events use deterministic IDs
(`hb_agent_runtime_v1:<bucket start>`) with `created_at` set to the
bucket start, so concurrent replicas race safely via `ON CONFLICT (id)
DO NOTHING` without locking, and daily rollups attribute backfilled
hours to the correct day. Idle hours produce zero-valued events. A
bucket becomes eligible 5 minutes after it closes; hours missing for
longer than the 7-day window are forfeited, which can only undercount.
Note that this makes `usage_events.created_at` explicitly the *event
occurrence time* rather than the row insertion time; the two only
diverge for backfilled events. It already behaved as the occurrence
timestamp (it drives the daily rollup day and is shipped to
Tallyman/Metronome as the event timestamp), and the migration now
documents this with a `COMMENT ON COLUMN`, which also surfaces as a Go
doc comment on `UsageEvent.CreatedAt`.
The new `usage.Generator` runs unconditionally in enterprise builds; the
`publish_usage_data` license flag continues to gate egress only, so
air-gapped deployments still fill their local ledger. The
`aggregate_usage_event()` trigger sums `runtime_ms` per day into
`usage_events_daily` (unlike `hb_ai_seats_v1`, which takes the daily
max).
`InsertHeartbeatUsageEvent` now takes an explicit `createdAt` so
generators can backfill historical buckets; the cron passes
`clock.Now()` to preserve its existing behavior.
## Tallyman follow-up
<details>
<summary>Prompt for the Tallyman-repo agent</summary>
> **Task**: Add support for the new Coder usage event type
`hb_agent_runtime_v1` so Tallyman accepts, validates, and forwards it to
Metronome.
>
> **Background**: coder/coder PR (this PR) adds hourly heartbeat events
measuring Coder Agent runtime. Events arrive via the existing
`/api/v1/events/ingest` endpoint with: `event_type:
"hb_agent_runtime_v1"`, `event_data: {"runtime_ms": <int64 >= 0>}`,
deterministic `id` of the form `hb_agent_runtime_v1:2026-07-15_14:00:00`
(UTC hour bucket start), and `created_at` set to the bucket start (may
be up to ~8 days in the past due to backfill; within Metronome's 34-day
dedup window). Zero-value events are normal (idle hours).
>
> **Work**:
> 1. Update Tallyman's vendored/imported `coderd/usage/usagetypes` (or
equivalent) to the coder/coder commit that adds
`UsageEventTypeHBAgentRuntimeV1` and `HBAgentRuntime`.
> 2. Ensure ingestion validation accepts the type (`Valid()` switches)
and rejects negative `runtime_ms`.
> 3. Ensure Metronome forwarding maps the event with transaction ID
derived from the event `id` as for existing types, passing `runtime_ms`
through as the property for a SUM-aggregated billable metric ("Coder
Agent Hours" = `SUM(runtime_ms) / 3,600,000`).
> 4. Do NOT permanently reject unknown-but-well-formed future `hb_*`
types if avoidable; at minimum confirm current behavior for unknown
types (temporary vs permanent rejection) and report it.
> 5. Tests: ingest accept/validate, dedup by ID, Metronome payload
mapping.
>
> **Constraint**: this must be deployed to tallyman-prod **before** any
coder/coder release containing the event generator; coderd treats
permanent rejections as terminal per event.
</details>
Fixes all our Go file imports to match the preferred spec that we've _mostly_ been using. For example:
```
import (
"context"
"time"
"github.com/prometheus/client_golang/prometheus"
"golang.org/x/xerrors"
"gopkg.in/natefinch/lumberjack.v2"
"cdr.dev/slog/v3"
"github.com/coder/coder/v2/codersdk/agentsdk"
"github.com/coder/serpent"
)
```
3 groups: standard library, 3rd partly libs, Coder libs.
This PR makes the change across the codebase. The PR in the stack above modifies our formatting to maintain this state of affairs, and is a separate PR so it's possible to review that one in detail.
Upgrades to slog v3 which includes a small, but backward incompatible API change to the acceptible call arguments when logging. This change allows us to verify via compile time type checking that arguments are correct and won't cause a panic, as was possible in slog v1, which this replaces (v2 was tagged but never used in coder/coder).
It also updates dependencies that also use slog and were updated.
I've left the `aibridge` dependency as a commit SHA, under the assumption that the team there (cc @pawbana @dannykopping ) will tag and update the dependency soon and on their own schedule.
Other dependencies, I pushed new tags.
- Adds `usagetypes.UnknownEventTypeError` type, which is returned by
`ParseEventWithType`
- Changes `ParseEvent` to not be a generic function since it doesn't
really need it
- Adds `User-Agent` to tallyman requests
Not used in coderd yet, see stack.
Adds two new packages:
- `coderd/usage`: provides an interface for the "Collector" as well as a stub implementation for AGPL
- `enterprise/coderd/usage`: provides an interface for the "Publisher" as well as a Tallyman implementation
Relates to https://github.com/coder/internal/issues/814
Jaayden Halko