feat: prompt library + {{placeholder}} templating

CHANGELOG.md

@@ -2,6 +2,8 @@ _Reverse-chronological record of shipped work — features, fixes, and chores. N
 
 # 2026-07-05
 
+- Prompt library — saved, reusable prompt templates inserted in the composer by typing `/<name>` (the roadmap v0.5 slash-commands seed, in its genuinely-useful form; validated by Open WebUI, which has the same `/` prompt menu). A `prompts` table (owner-scoped, FORCE RLS, `UNIQUE(user_id, name)`, migration 0015) + `/api/v1/me/prompts` CRUD (GET/POST/PATCH/DELETE), mirroring the memories pattern — the `name` is a slug (`^[A-Za-z0-9_-]+$`, DB CHECK) so `/<name>` is unambiguous, and a duplicate name is a real 409 (DB unique + a `23505`-walking catch, stricter than the memories pre-check). Manage prompts in Settings; insert them in a chat via a `/` autocomplete menu. A two-reviewer round hardened the composer: the trigger is `^/(\S+)$` — bare `/` never opens the menu, so a literal `/` message still sends (the adversarial reviewer's literal-send trap); prefix matching is case-insensitive; only BARE Enter selects (Shift+Enter falls through to a newline); the menu list comes from a single shared `usePromptsQuery()` (fetched once, filtered per keystroke, invalidated by a settings edit). The core-composer change is minimal + backward-compatible: `PromptInputTextarea` now calls a passed `onKeyDown` first and bails if it `preventDefault`ed (before that, a passed handler silently clobbered Enter-to-send). Verified: 7 prompts RLS integration cases (owner CRUD, cross-tenant denied, per-user unique name but same-name-across-users allowed, a case-insensitive name conflict for the same user, slug + content CHECKs, and a concurrent-create race proving the per-user cap holds under `pg_advisory_xact_lock`), plus pure-trigger and web service cases, prompts route in openapi.json, api + web build/lint/tsc clean.
+- Prompt templating — saved prompts can now carry `{{placeholder}}` variables, completing the prompt library into genuinely reusable, parameterized prompts. When you insert a prompt that has placeholders (via `/name`), a small fill-in dialog collects a value per unique placeholder and substitutes them into the composer; a plain prompt inserts directly as before. Client-only, no schema change (placeholders are plain text in the prompt body). Chosen a fill DIALOG over inline cursor-jump templating deliberately — it sidesteps textarea DOM-ref/selection machinery and is complete for any number of variables + fully unit-testable via pure `extractPlaceholders`/`fillPlaceholders`. A two-reviewer round hardened it: substitution is a SINGLE `String.replace(regex, callback)` pass over the original body (so a value that itself contains `{{x}}` is never re-expanded); the `/` menu is dismissed via `setDismissedFor(input)` when the dialog opens (no menu-behind-dialog glitch or cancel-reopen loop); the regex is ReDoS-safe (`{{([^{}]*?)}}`, no overlapping quantifiers); and the dialog field ids are INDEX-based, because a placeholder name can contain spaces (`{{target language}}`) which is invalid in a DOM id and would break `label[for]`. Verified: 8 pure templating cases (unique/ordered extraction, dedupe, empty `{{}}` ignored, substitution, duplicate-fill, unfilled→empty, no-double-expansion), web build/lint/tsc clean; no api/schema touched.
 - Hardened `apps/api/scripts/rls-test.sh`'s readiness wait: it now also confirms the published Postgres port is reachable from the **host** (bash `/dev/tcp`), not just that `pg_isready` succeeds inside the container — under WSL2/Docker the host port-forward can lag the container's internal readiness, which previously let the migration step connect too early and hit `CONNECT_TIMEOUT`.
 
 # 2026-07-04

apps/api/AGENTS.md

@@ -10,8 +10,8 @@ NestJS 11 backend: API + services, and owner of the database schema/migrations.
 
 ## Structure
 
-- `src/` — one directory per feature, each a NestJS module (`chats/`, `runs/`, `compaction/`, `titles/`, `queue/`, `models/`, `auth/`, `users/`, `db/`); a feature another feature consumes exports its service from its own module, never re-provided elsewhere. Boundary rules: `queue/` is consumed ONLY by `runs/` (chats dispatches runs via `RunDispatchService` and never sees queue names/payloads); `runs/` hosts the whole execution domain (executor, worker consumers, dispatch, stream bridge — `RunWorkerModule` is what the dedicated worker entrypoint (#116) will boot); `db/DbModule` is the single global `TenantDbService` provider
-- `src/db/` — `schema/` (`auth.ts`, `chats.ts`), `migrations/` (+ `meta/` journal), `migrate.ts`
+- `src/` — one directory per feature, each a NestJS module (`chats/`, `runs/`, `compaction/`, `titles/`, `queue/`, `models/`, `auth/`, `users/`, `prompts/`, `db/`); a feature another feature consumes exports its service from its own module, never re-provided elsewhere. Boundary rules: `queue/` is consumed ONLY by `runs/` (chats dispatches runs via `RunDispatchService` and never sees queue names/payloads); `runs/` hosts the whole execution domain (executor, worker consumers, dispatch, stream bridge — `RunWorkerModule` is what the dedicated worker entrypoint (#116) will boot); `db/DbModule` is the single global `TenantDbService` provider
+- `src/db/` — `schema/` (`auth.ts`, `chats.ts`, `prompts.ts`), `migrations/` (+ `meta/` journal), `migrate.ts`
 - `src/main.ts`, `src/app.module.ts`
 
 ## Commands
@@ -58,4 +58,4 @@ Migrations run as a **non-superuser `app` role that owns the schema** (provision
 
 - `apps/api/src/db` is the **sole** schema; `apps/web` owns no database.
 - Linting is oxlint with type-aware rules (`.oxlintrc.json`, `options.typeAware`) running on **tsgo** (TypeScript 7). tsgo rejects `baseUrl`, so `tsconfig.json` must not reintroduce it, and global test/node types are declared explicitly via `"types": ["node", "jest"]` (tsgo does not auto-include `@types/*` under pnpm the way tsc does). Formatting is prettier (`pnpm format`), checked in CI via the root `format:check` — it is no longer an ESLint rule.
-- Migrations are `drizzle-kit`-generated (`0005`+). Hand-authored exceptions: `0004` (the PoC → multi-tenant transition — drizzle-kit's interactive column-rename can't be driven non-interactively; `FORCE ROW LEVEL SECURITY` is hand-maintained here too, Drizzle can't express it), `0006` (the sessions hashing migration carries a manual `DELETE FROM sessions` — raw tokens can't be carried into the hashed-at-rest model), `0010` (the nullable-title migration carries a manual `UPDATE` backfilling old default-literal titles to NULL, and drops a spurious generated DROP/CREATE of the unchanged `sessions_user_created_idx`), `0011` (the durable-runs migration hand-appends `FORCE ROW LEVEL SECURITY` for `runs`/`run_events` — Drizzle emits ENABLE only — and hand-reorders the composite-key unique indexes before the FKs that reference them), `0012` (the single-flight migration carries a manual `UPDATE` cancelling all but the newest non-terminal run per chat — the partial unique index cannot be created over duplicates — plus matching `run.cancelled` events, applied inside a NO FORCE RLS window since migrations run as the owning role), and `0013` (the `in_reply_to` reply-integrity trigger, #73 — Drizzle can't express triggers). `drizzle-kit check` passes for all. Re-add the manual steps if you ever regenerate these.
+- Migrations are `drizzle-kit`-generated (`0005`+). Hand-authored exceptions: `0004` (the PoC → multi-tenant transition — drizzle-kit's interactive column-rename can't be driven non-interactively; `FORCE ROW LEVEL SECURITY` is hand-maintained here too, Drizzle can't express it), `0006` (the sessions hashing migration carries a manual `DELETE FROM sessions` — raw tokens can't be carried into the hashed-at-rest model), `0010` (the nullable-title migration carries a manual `UPDATE` backfilling old default-literal titles to NULL, and drops a spurious generated DROP/CREATE of the unchanged `sessions_user_created_idx`), `0011` (the durable-runs migration hand-appends `FORCE ROW LEVEL SECURITY` for `runs`/`run_events` — Drizzle emits ENABLE only — and hand-reorders the composite-key unique indexes before the FKs that reference them), `0012` (the single-flight migration carries a manual `UPDATE` cancelling all but the newest non-terminal run per chat — the partial unique index cannot be created over duplicates — plus matching `run.cancelled` events, applied inside a NO FORCE RLS window since migrations run as the owning role), `0013` (the `in_reply_to` reply-integrity trigger, #73 — Drizzle can't express triggers), and `0015` (the prompt-library migration hand-appends `FORCE ROW LEVEL SECURITY` for `prompts`, same pattern as `0004`/`0011`). `drizzle-kit check` passes for all. Re-add the manual steps if you ever regenerate these.

apps/api/openapi.json

@@ -757,6 +757,178 @@
           "runs"
         ]
       }
+    },
+    "/api/v1/me/prompts": {
+      "get": {
+        "operationId": "MePromptsController_list",
+        "parameters": [],
+        "responses": {
+          "200": {
+            "description": "",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/components/schemas/PromptResponse"
+                  }
+                }
+              }
+            }
+          },
+          "401": {
+            "description": ""
+          }
+        },
+        "security": [
+          {
+            "cookie": []
+          },
+          {
+            "bearer": []
+          }
+        ],
+        "tags": [
+          "me"
+        ]
+      },
+      "post": {
+        "operationId": "MePromptsController_create",
+        "parameters": [],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/CreatePromptDto"
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/PromptResponse"
+                }
+              }
+            }
+          },
+          "401": {
+            "description": ""
+          },
+          "409": {
+            "description": "Duplicate name, or at the per-user prompt cap"
+          }
+        },
+        "security": [
+          {
+            "cookie": []
+          },
+          {
+            "bearer": []
+          }
+        ],
+        "tags": [
+          "me"
+        ]
+      }
+    },
+    "/api/v1/me/prompts/{id}": {
+      "patch": {
+        "operationId": "MePromptsController_update",
+        "parameters": [
+          {
+            "name": "id",
+            "required": true,
+            "in": "path",
+            "schema": {
+              "format": "uuid",
+              "type": "string"
+            }
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/UpdatePromptDto"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/PromptResponse"
+                }
+              }
+            }
+          },
+          "401": {
+            "description": ""
+          },
+          "404": {
+            "description": "Unknown or cross-tenant prompt"
+          },
+          "409": {
+            "description": "Rename collides with an existing prompt"
+          }
+        },
+        "security": [
+          {
+            "cookie": []
+          },
+          {
+            "bearer": []
+          }
+        ],
+        "tags": [
+          "me"
+        ]
+      },
+      "delete": {
+        "operationId": "MePromptsController_remove",
+        "parameters": [
+          {
+            "name": "id",
+            "required": true,
+            "in": "path",
+            "schema": {
+              "format": "uuid",
+              "type": "string"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": ""
+          },
+          "401": {
+            "description": ""
+          },
+          "404": {
+            "description": "Unknown or cross-tenant prompt"
+          }
+        },
+        "security": [
+          {
+            "cookie": []
+          },
+          {
+            "bearer": []
+          }
+        ],
+        "tags": [
+          "me"
+        ]
+      }
     }
   },
   "info": {
@@ -1246,6 +1418,72 @@
         "required": [
           "status"
         ]
+      },
+      "PromptResponse": {
+        "type": "object",
+        "properties": {
+          "id": {
+            "type": "string",
+            "format": "uuid"
+          },
+          "name": {
+            "type": "string",
+            "maxLength": 64
+          },
+          "content": {
+            "type": "string",
+            "maxLength": 8000
+          },
+          "createdAt": {
+            "format": "date-time",
+            "type": "string"
+          },
+          "updatedAt": {
+            "format": "date-time",
+            "type": "string"
+          }
+        },
+        "required": [
+          "id",
+          "name",
+          "content",
+          "createdAt",
+          "updatedAt"
+        ]
+      },
+      "CreatePromptDto": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string",
+            "maxLength": 64,
+            "pattern": "^[A-Za-z0-9_-]+$"
+          },
+          "content": {
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 8000
+          }
+        },
+        "required": [
+          "name",
+          "content"
+        ]
+      },
+      "UpdatePromptDto": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string",
+            "maxLength": 64,
+            "pattern": "^[A-Za-z0-9_-]+$"
+          },
+          "content": {
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 8000
+          }
+        }
       }
     }
   }

apps/api/scripts/rls-test.sh

@@ -81,6 +81,9 @@ echo "▶ applying migrations as 'app' (so app owns every table)"
 echo "▶ running RLS integration suite as 'app'"
 ( cd "$API_DIR" && TEST_DATABASE_URL="$APP_URL" pnpm exec jest chats-rls.integration --silent=false )
 
+echo "▶ running prompts RLS integration suite as 'app'"
+( cd "$API_DIR" && TEST_DATABASE_URL="$APP_URL" pnpm exec jest prompts-rls.integration --silent=false )
+
 echo "▶ running queue integration suite (pg-boss on the same throwaway Postgres)"
 ( cd "$API_DIR" && TEST_DATABASE_URL="$APP_URL" pnpm exec jest queue.integration --silent=false )
 

apps/api/src/app.module.ts

@@ -8,6 +8,7 @@ import { AppService } from './app.service';
 import { UsersModule } from './users/users.module';
 import { ChatsModule } from './chats/chats.module';
 import { DbModule } from './db/db.module';
+import { PromptsModule } from './prompts/prompts.module';
 import { RunsModule } from './runs/runs.module';
 import { AuthModule } from './auth/auth.module';
 import { SessionAuthGuard } from './auth/session-auth.guard';
@@ -43,6 +44,7 @@ import * as schema from './db/schema';
     UsersModule,
     DbModule,
     ChatsModule,
+    PromptsModule,
     RunsModule,
   ],
   controllers: [AppController],

apps/api/src/db/migrations/0015_wonderful_caretaker.sql

@@ -0,0 +1,16 @@
+CREATE TABLE "prompts" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"user_id" text NOT NULL,
+	"name" text NOT NULL,
+	"content" text NOT NULL,
+	"created_at" timestamp with time zone DEFAULT now() NOT NULL,
+	"updated_at" timestamp with time zone DEFAULT now() NOT NULL,
+	CONSTRAINT "prompts_name_slug" CHECK ("prompts"."name" ~ '^[A-Za-z0-9_-]{1,64}$'),
+	CONSTRAINT "prompts_content_len" CHECK (char_length("prompts"."content") BETWEEN 1 AND 8000)
+);
+--> statement-breakpoint
+ALTER TABLE "prompts" ENABLE ROW LEVEL SECURITY;--> statement-breakpoint
+ALTER TABLE "prompts" FORCE ROW LEVEL SECURITY;--> statement-breakpoint
+ALTER TABLE "prompts" ADD CONSTRAINT "prompts_user_id_users_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."users"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
+CREATE UNIQUE INDEX "prompts_user_name_idx" ON "prompts" USING btree ("user_id",lower("name"));--> statement-breakpoint
+CREATE POLICY "prompts_owner" ON "prompts" AS PERMISSIVE FOR ALL TO public USING (user_id = current_setting('app.current_user_id', true));