feat: prompt library + {{placeholder}} templating

CHANGELOG.md

@@ -1,5 +1,10 @@
 _Reverse-chronological record of shipped work — features, fixes, and chores. Newest first._
 
+# 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: 5 prompts RLS integration cases (owner CRUD, cross-tenant denied, per-user unique name but same-name-across-users allowed, slug + content CHECKs), 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.
+
 # 2026-07-04
 
 - Fixed `pnpm --filter web dev` in git worktrees after the Next 16/Turbopack upgrade: the script now launches Next from the monorepo root with `apps/web` as the project directory, avoiding Turbopack's mixed-root module graph that made authenticated chat pages fail with `Cannot find module '@workspace/ui/globals.css'` while unauthenticated/login routes still appeared healthy.

apps/api/AGENTS.md

@@ -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

@@ -626,6 +626,178 @@
         ]
       }
     },
+    "/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"
+        ]
+      }
+    },
     "/api/v1/runs/{id}": {
       "get": {
         "operationId": "RunsController_getRun",
@@ -1168,6 +1340,72 @@
           }
         }
       },
+      "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
+          }
+        }
+      },
       "RunResponse": {
         "type": "object",
         "properties": {

apps/api/scripts/rls-test.sh

@@ -57,6 +57,9 @@ 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/chats/chats.module.ts

@@ -6,6 +6,7 @@ import { RunsModule } from '../runs/runs.module';
 import { ChatLoopService } from './chat-loop.service';
 import { ChatsController } from './chats.controller';
 import { ChatsService } from './chats.service';
+import { MePromptsController } from './me-prompts.controller';
 
 // HTTP endpoints are safe to expose only because SessionAuthGuard derives the tenant
 // identity from a verified session. Controllers must never accept ownerUserId from
@@ -17,7 +18,7 @@ import { ChatsService } from './chats.service';
 // queues, workers, compaction, or titling.
 @Module({
   imports: [AuthModule, ModelsModule, RunsModule, RunWorkerModule],
-  controllers: [ChatsController],
+  controllers: [ChatsController, MePromptsController],
   providers: [ChatsService, ChatLoopService],
   exports: [ChatsService],
 })

apps/api/src/chats/dto/prompts.dto.ts

@@ -0,0 +1,79 @@
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+import {
+  IsOptional,
+  IsString,
+  Matches,
+  MaxLength,
+  MinLength,
+} from 'class-validator';
+
+import {
+  PROMPT_CONTENT_MAX,
+  PROMPT_NAME_MAX,
+  type Prompt,
+} from '../../db/schema';
+
+// The slash trigger: a slug (no whitespace/slashes) so `/<name>` is exact.
+const NAME_PATTERN = /^[A-Za-z0-9_-]+$/;
+const NAME_MESSAGE =
+  'name must be a slug: letters, digits, underscore or hyphen (no spaces)';
+
+export class CreatePromptDto {
+  @ApiProperty({ maxLength: PROMPT_NAME_MAX, pattern: NAME_PATTERN.source })
+  @IsString()
+  @Matches(NAME_PATTERN, { message: NAME_MESSAGE })
+  @MaxLength(PROMPT_NAME_MAX)
+  name!: string;
+
+  @ApiProperty({ minLength: 1, maxLength: PROMPT_CONTENT_MAX })
+  @IsString()
+  @MinLength(1)
+  @MaxLength(PROMPT_CONTENT_MAX)
+  content!: string;
+}
+
+export class UpdatePromptDto {
+  @ApiPropertyOptional({
+    maxLength: PROMPT_NAME_MAX,
+    pattern: NAME_PATTERN.source,
+  })
+  @IsOptional()
+  @IsString()
+  @Matches(NAME_PATTERN, { message: NAME_MESSAGE })
+  @MaxLength(PROMPT_NAME_MAX)
+  name?: string;
+
+  @ApiPropertyOptional({ minLength: 1, maxLength: PROMPT_CONTENT_MAX })
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(PROMPT_CONTENT_MAX)
+  content?: string;
+}
+
+export class PromptResponse {
+  @ApiProperty({ format: 'uuid' })
+  id!: string;
+
+  @ApiProperty({ maxLength: PROMPT_NAME_MAX })
+  name!: string;
+
+  @ApiProperty({ maxLength: PROMPT_CONTENT_MAX })
+  content!: string;
+
+  @ApiProperty({ format: 'date-time' })
+  createdAt!: Date;
+
+  @ApiProperty({ format: 'date-time' })
+  updatedAt!: Date;
+}
+
+export function toPromptResponse(prompt: Prompt): PromptResponse {
+  return {
+    id: prompt.id,
+    name: prompt.name,
+    content: prompt.content,
+    createdAt: prompt.createdAt,
+    updatedAt: prompt.updatedAt,
+  };
+}