1# Configuration
2 
3## Script Loading
4 
5```js
6// Inline
7new Miniflare({ modules: true, script: `export default { ... }` });
8 
9// File-based
10new Miniflare({ scriptPath: "worker.js" });
11 
12// Multi-module
13new Miniflare({
14  scriptPath: "src/index.js",
15  modules: true,
16  modulesRules: [
17    { type: "ESModule", include: ["**/*.js"] },
18    { type: "Text", include: ["**/*.txt"] },
19  ],
20});
21```
22 
23## Compatibility
24 
25```js
26new Miniflare({
27  compatibilityDate: "2026-01-01", // Use recent date for latest features
28  compatibilityFlags: [
29    "nodejs_compat",        // Node.js APIs (process, Buffer, etc)
30    "streams_enable_constructors", // Stream constructors
31  ],
32  upstream: "https://example.com", // Fallback for unhandled requests
33});
34```
35 
36**Critical:** Use `compatibilityDate: "2026-01-01"` or latest to match production runtime. Old dates limit available APIs.
37 
38## HTTP Server & Request.cf
39 
40```js
41new Miniflare({
42  port: 8787,              // Default: 8787
43  host: "127.0.0.1",
44  https: true,             // Self-signed cert
45  liveReload: true,        // Auto-reload HTML
46  
47  cf: true,                // Fetch live Request.cf data (cached)
48  // cf: "./cf.json",      // Or load from file
49  // cf: { colo: "DFW" },  // Or inline mock
50});
51```
52 
53**Note:** For tests, use `dispatchFetch()` (no port conflicts).
54 
55## Storage Bindings
56 
57```js
58new Miniflare({
59  // KV
60  kvNamespaces: ["TEST_NAMESPACE", "CACHE"],
61  kvPersist: "./kv-data", // Optional: persist to disk
62  
63  // R2
64  r2Buckets: ["BUCKET", "IMAGES"],
65  r2Persist: "./r2-data",
66  
67  // Durable Objects
68  modules: true,
69  durableObjects: {
70    COUNTER: "Counter", // className
71    API_OBJECT: { className: "ApiObject", scriptName: "api-worker" },
72  },
73  durableObjectsPersist: "./do-data",
74  
75  // D1
76  d1Databases: ["DB"],
77  d1Persist: "./d1-data",
78  
79  // Cache
80  cache: true, // Default
81  cachePersist: "./cache-data",
82});
83```
84 
85## Bindings
86 
87```js
88new Miniflare({
89  // Environment variables
90  bindings: {
91    SECRET_KEY: "my-secret-value",
92    API_URL: "https://api.example.com",
93    DEBUG: true,
94  },
95  
96  // Other bindings
97  wasmBindings: { ADD_MODULE: "./add.wasm" },
98  textBlobBindings: { TEXT: "./data.txt" },
99  queueProducers: ["QUEUE"],
100});
101```
102 
103## Multiple Workers
104 
105```js
106new Miniflare({
107  workers: [
108    {
109      name: "main",
110      kvNamespaces: { DATA: "shared" },
111      serviceBindings: { API: "api-worker" },
112      script: `export default { ... }`,
113    },
114    {
115      name: "api-worker",
116      kvNamespaces: { DATA: "shared" }, // Shared storage
117      script: `export default { ... }`,
118    },
119  ],
120});
121```
122 
123**With routing:**
124```js
125workers: [
126  { name: "api", scriptPath: "./api.js", routes: ["api.example.com/*"] },
127  { name: "web", scriptPath: "./web.js", routes: ["example.com/*"] },
128],
129```
130 
131## Logging & Performance
132 
133```js
134import { Log, LogLevel } from "miniflare";
135 
136new Miniflare({
137  log: new Log(LogLevel.DEBUG), // DEBUG | INFO | WARN | ERROR | NONE
138  scriptTimeout: 30000,         // CPU limit (ms)
139  workersConcurrencyLimit: 10,  // Max concurrent workers
140});
141```
142 
143## Workers Sites
144 
145```js
146new Miniflare({
147  sitePath: "./public",
148  siteInclude: ["**/*.html", "**/*.css"],
149  siteExclude: ["**/*.map"],
150});
151```
152 
153## From wrangler.toml
154 
155Miniflare doesn't auto-read `wrangler.toml`:
156 
157```toml
158# wrangler.toml
159name = "my-worker"
160main = "src/index.ts"
161compatibility_date = "2026-01-01"
162[[kv_namespaces]]
163binding = "KV"
164```
165 
166```js
167// Miniflare equivalent
168new Miniflare({
169  scriptPath: "src/index.ts",
170  compatibilityDate: "2026-01-01",
171  kvNamespaces: ["KV"],
172});
173```
174