1# C3 Generated Configuration
2 
3## Output Structure
4 
5```
6my-app/
7├── src/index.ts          # Worker entry point
8├── wrangler.jsonc        # Cloudflare config
9├── package.json          # Scripts
10├── tsconfig.json
11└── .gitignore
12```
13 
14## wrangler.jsonc
15 
16```jsonc
17{
18  "$schema": "https://raw.githubusercontent.com/cloudflare/workers-sdk/main/packages/wrangler/config-schema.json",
19  "name": "my-app",
20  "main": "src/index.ts",
21  "compatibility_date": "2026-01-27"
22}
23```
24 
25## Binding Placeholders
26 
27C3 generates **placeholder IDs** that must be replaced before deploy:
28 
29```jsonc
30{
31  "kv_namespaces": [{ "binding": "MY_KV", "id": "placeholder_kv_id" }],
32  "d1_databases": [{ "binding": "DB", "database_id": "00000000-..." }]
33}
34```
35 
36**Replace with real IDs:**
37```bash
38npx wrangler kv namespace create MY_KV   # Returns real ID
39npx wrangler d1 create my-database       # Returns real database_id
40```
41 
42**Deployment error if not replaced:**
43```
44Error: Invalid KV namespace ID "placeholder_kv_id"
45```
46 
47## Scripts
48 
49```json
50{
51  "scripts": {
52    "dev": "wrangler dev",
53    "deploy": "wrangler deploy",
54    "cf-typegen": "wrangler types"
55  }
56}
57```
58 
59## Type Generation
60 
61Run after adding bindings:
62```bash
63npm run cf-typegen
64```
65 
66Generates `.wrangler/types/runtime.d.ts`:
67```typescript
68interface Env {
69  MY_KV: KVNamespace;
70  DB: D1Database;
71}
72```
73 
74## Post-Creation Checklist
75 
761. Review `wrangler.jsonc` - check name, compatibility_date
772. Replace placeholder binding IDs with real resource IDs
783. Run `npm run cf-typegen`
794. Test: `npm run dev`
805. Deploy: `npm run deploy`
816. Add secrets: `npx wrangler secret put SECRET_NAME`
82