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.
2026-09-24 15:04:27 +08:00 · 2026-06-15 14:41:00 -07:00
parent 89f200872b
commit 210261b143
18 changed files with 1116 additions and 140 deletions
@@ -0,0 +1,54 @@
+-- Recreate chats_expanded without the new chat columns. The view must
+-- be dropped before the columns it references can be removed.
+DROP VIEW IF EXISTS chats_expanded;
+
+ALTER TABLE chats
+    DROP COLUMN IF EXISTS context_aggregate_hash,
+    DROP COLUMN IF EXISTS context_dirty_since,
+    DROP COLUMN IF EXISTS context_dirty_resources,
+    DROP COLUMN IF EXISTS context_error;
+
+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
+   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)));
@@ -0,0 +1,70 @@
+-- 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)));