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coder/coderd/database/migrations/000523_chat_context_hydration.up.sql
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Kyle Carberry 210261b143 feat: add chat context pinning storage and push trigger (#26385)
Foundation for the Workspace Context Sources RFC (phase 3). The agent
push (#25983) and coderd snapshot storage (#26145) already persist
per-agent context snapshots; this PR lands the **chat-side storage**
plus the **`agentapi` push trigger** that a follow-up will use to read
them. It does **not** touch `chatd` and changes no behavior — nothing
wires an implementation yet.

## What changed

- Adds four nullable columns to `chats` — `context_aggregate_hash`,
`context_dirty_since`, `context_dirty_resources`, and `context_error` —
and rebuilds the `chats_expanded` view.
- Adds three queries — `SetChatContextSnapshot`,
`HydrateAgentChatsContext`, `MarkChatsContextDirtyByAgent` — with
`dbauthz` wrappers and `audit` entries. They are store-interface methods
covered by a Postgres test (`TestChatContextHydration`).
- Adds the `agentapi.ContextDirtyMarker` interface and invokes it inside
the `PushContextState` transaction, publishing collected events only
after commit.

## Intentionally inert

There are **no production callers** of the three queries and **no
implementation** wired for `ContextDirtyMarker`, so the push trigger is
dormant. This is deliberate: the PR is the durable storage/query
foundation only.

The actual integration — the `chatd` implementation that
hydrates/dirties chats and backs a refresh endpoint, consuming the
pinned context in prompt building, the rich SDK types + UI, and retiring
the live per-turn pull — lands as a single follow-up PR. Splitting this
way keeps the schema/query layer reviewable on its own and keeps the
integration whole in one place.

Refs #25983, #26145.

<details>
<summary>Decision log</summary>

- **Columns over a side table.** The four `chats` columns are the
durable model (accepting the one-time `chats_expanded` view/CTE churn).
`last_injected_context` is deliberately left untouched — it is
load-bearing for the live per-turn context pull.
- **Keep `agentapi`, drop `chatd`.** The earlier revision wired the
hydrate/dirty implementation through `chatd` and added a `PUT
/chats/{chat}/context` refresh endpoint. Those were removed so this PR
is pure foundation; `agentapi` defines the trigger + interface (it does
not import `chatd`), and the `chatd` implementation arrives with the
full integration.
- **No new experiment flag.** The columns are dark and unread by prompt
building.
- **Authz.** The new query wrappers authorize chat updates under the
chat RBAC object / `ResourceChat`, consistent with the existing system
chat mutators.

</details>

---

🤖 Generated by Coder Agents on behalf of @kylecarbs.
2026-06-15 14:41:00 -07:00

71 lines
2.7 KiB
SQL

-- Chat-side pin of the agent's latest pushed context snapshot
-- (workspace_agent_context_snapshots). Written by hydration (chat
-- create and agent push) and the dirty fan-out, and re-pinned by the
-- refresh endpoint. These columns are dark plumbing: they do not feed
-- prompt building and the per-turn context pull is unchanged. They are
-- read by drift detection and the refresh endpoint only.
ALTER TABLE chats
ADD COLUMN context_aggregate_hash bytea,
ADD COLUMN context_dirty_since timestamptz,
ADD COLUMN context_dirty_resources jsonb,
ADD COLUMN context_error text NOT NULL DEFAULT '';
COMMENT ON COLUMN chats.context_aggregate_hash IS 'Aggregate hash of the agent context snapshot this chat is pinned to. NULL until first hydrated; compared against the agent''s latest snapshot hash to detect drift.';
COMMENT ON COLUMN chats.context_dirty_since IS 'Set when an agent push changes the pinned hash; cleared on refresh. NULL means clean.';
COMMENT ON COLUMN chats.context_dirty_resources IS 'Deterministic prefix of resources that changed since the pinned hash. Reserved for the dirty diff; left NULL until the UI phase populates it.';
COMMENT ON COLUMN chats.context_error IS 'Snapshot-level error copied from the pinned snapshot (count cap exceeded, watcher degraded, etc.). Empty when healthy.';
-- Refresh chats_expanded to include the new chat columns. The gentest
-- TestViewSubsetChat requires every chats column to appear in the view.
-- Drop and recreate because a view cannot have columns inserted in the
-- middle of its column list.
DROP VIEW IF EXISTS chats_expanded;
CREATE VIEW chats_expanded AS
SELECT c.id,
c.owner_id,
c.workspace_id,
c.title,
c.status,
c.worker_id,
c.started_at,
c.heartbeat_at,
c.created_at,
c.updated_at,
c.parent_chat_id,
c.root_chat_id,
c.last_model_config_id,
c.archived,
c.last_error,
c.mode,
c.mcp_server_ids,
c.labels,
c.build_id,
c.agent_id,
c.pin_order,
c.last_read_message_id,
c.last_injected_context,
c.dynamic_tools,
c.organization_id,
c.plan_mode,
c.client_type,
c.last_turn_summary,
c.snapshot_version,
c.history_version,
c.queue_version,
c.generation_attempt,
c.retry_state,
c.retry_state_version,
c.runner_id,
c.requires_action_deadline_at,
COALESCE(root.user_acl, c.user_acl) AS user_acl,
COALESCE(root.group_acl, c.group_acl) AS group_acl,
owner.username AS owner_username,
owner.name AS owner_name,
c.context_aggregate_hash,
c.context_dirty_since,
c.context_dirty_resources,
c.context_error
FROM ((chats c
LEFT JOIN chats root ON ((root.id = COALESCE(c.root_chat_id, c.parent_chat_id))))
JOIN visible_users owner ON ((owner.id = c.owner_id)));