4
5* `index.ts` - this is the **entrypoint** for this whole project
6* `database/` - this contains the code for interfacing with the app's SQLite database table
7
8## Hono
26## CRUD API Routes
27
28This app has two CRUD API routes: for reading and inserting into the messages table. They both speak JSON, which is standard. They import their functions from `/backend/database/queries.ts`. These routes are called from the React app to refresh and update data.
29
30## Errors
1# Database
2
3This app uses [Val Town SQLite](https://docs.val.town/std/sqlite/) to manage data. Every Val Town account comes with a free SQLite database, hosted on [Turso](https://turso.tech/). This folder is broken up into two files:
4
5* `migrations.ts` - code to set up the database tables the app needs
6* `queries.ts` - functions to run queries against those tables, which are imported and used in the main Hono server in `/backend/index.ts`
7
8## Migrations
9
10In `backend/database/migrations.ts`, this app creates a new SQLite table `reactHonoStarter_messages` to store messages.
11
12This "migration" runs once on every app startup because it's imported in `index.ts`. You can comment this line out for a slight (30ms) performance improvement on cold starts. It's left in so that users who fork this project will have the migration run correctly.
13
14SQLite has much more limited support for altering existing tables as compared to other databases. Often it's easier to create new tables with the schema you want, and then copy the data over. Happily LLMs are quite good at those sort of database operations, but please reach out in the [Val Town Discord](https://discord.com/invite/dHv45uN5RY) if you need help.
15
16## Queries
17
18The queries file is where running the migrations happen in this app. It'd also be reasonable for that to happen in index.ts, or as is said above, for that line to be commented out, and only run when actual changes are made to your database schema.
19
20The queries file exports functions to get and write data. It relies on shared types and data imported from the `/shared` directory.
374];
375
376// Insert memories into the database
377async function insertDemoMemories() {
378 try {
415 await insertDemoMemories();
416
417 console.log("Demo database successfully populated!");
418 return "Demo database successfully populated!";
419 } catch (error) {
420 console.error("Error populating demo database:", error);
421 throw error;
422 }
2
3/**
4 * Retrieves all memories from the database
5 * @param includeDate Whether to include date-specific memories or not
6 * @param startDate Optional start date to filter memories from (ISO format)
6import { Hono } from "npm:hono";
7import { type Memory } from "../shared/types.ts";
8import { createMemory, deleteMemory, getAllMemories, updateMemory } from "./database/queries.ts";
9
10const app = new Hono();
34
35/**
36 * Store a chat message in the database
37 */
38export async function storeChatMessage(
208```
209โโโ backend/
210โ โโโ database/
211โ โ โโโ migrations.ts # Schema definitions
212โ โ โโโ queries.ts # DB query functions
270- Handle API calls properly with proper error catching
271
272### Database Patterns
273- Run migrations on startup or comment out for performance
274- Change table names when modifying schemas rather than altering
219```
220โโโ backend/
221โ โโโ database/
222โ โ โโโ migrations.ts # Schema definitions
223โ โ โโโ queries.ts # DB query functions
278 ```
279
280### Database Patterns
281- Run migrations on startup or comment out for performance
282- Change table names when modifying schemas rather than altering
10GlobalRateLimitedChatOpenAI(model: string, requestsPerSecond: number): Decorator for ChatOpenAI that enforces a global rate limit (requests per second) using a persistent SQLite table.
11GlobalRateLimiter: Class that implements the rate limiting logic. It checks the number of requests in the current time window and throws an error if the limit is exceeded. It uses a table (global_rate_limit_1) in Val Town's SQLite.
12ensureGlobalRateLimitTableExists: Ensures the rate limit tracking table exists in the database at startup.
13Usage
14Use ChatOpenAI(model) for direct, unlimited access to OpenAI chat completions.
198```
199โโโ backend/
200โ โโโ database/
201โ โ โโโ migrations.ts # Schema definitions
202โ โ โโโ queries.ts # DB query functions
257 ```
258
259### Database Patterns
260- Run migrations on startup or comment out for performance
261- Change table names when modifying schemas rather than altering