1# Workflow Configuration
2 
3## wrangler.jsonc Setup
4 
5```jsonc
6{
7  "name": "my-worker",
8  "main": "src/index.ts",
9  "compatibility_date": "2025-01-01",  // Minimum 2024-10-22 required for Workflows bindings
10  "observability": {
11    "enabled": true  // Enables Workflows dashboard + structured logs
12  },
13  "workflows": [
14    {
15      "name": "my-workflow",           // Workflow name
16      "binding": "MY_WORKFLOW",        // Env binding
17      "class_name": "MyWorkflow",      // TS class name
18      // "script_name": "other-worker" // For cross-script calls
19      // "limits": { "steps": 25000 }  // Optional: max steps per instance (check docs for default/max per plan)
20    }
21  ],
22  "limits": {
23    "cpu_ms": 300000  // Check docs for default and max CPU time per plan
24  }
25}
26```
27 
28## Step Configuration
29 
30```typescript
31// Basic step
32const data = await step.do('step name', async () => ({ result: 'value' }));
33 
34// With retry config
35await step.do('api call', {
36  retries: {
37    limit: 10,              // Accepts number or Infinity
38    delay: '10 seconds',    // Accepts number (ms) or duration string
39    backoff: 'exponential'  // constant | linear | exponential
40  },
41  timeout: '30 minutes'     // Per-attempt timeout
42}, async () => {
43  const res = await fetch('https://api.example.com/data');
44  if (!res.ok) throw new Error('Failed');
45  return res.json();
46});
47```
48 
49### Parallel Steps
50```typescript
51const [user, settings] = await Promise.all([
52  step.do('fetch user', async () => this.env.KV.get(`user:${id}`)),
53  step.do('fetch settings', async () => this.env.KV.get(`settings:${id}`))
54]);
55```
56 
57### Conditional Steps
58```typescript
59const config = await step.do('fetch config', async () => 
60  this.env.KV.get('flags', { type: 'json' })
61);
62 
63// ✅ Deterministic (based on step output)
64if (config.enableEmail) {
65  await step.do('send email', async () => sendEmail());
66}
67 
68// ❌ Non-deterministic (Date.now outside step)
69if (Date.now() > deadline) { /* BAD */ }
70```
71 
72### Dynamic Steps (Loops)
73```typescript
74const files = await step.do('list files', async () => 
75  this.env.BUCKET.list()
76);
77 
78for (const file of files.objects) {
79  await step.do(`process ${file.key}`, async () => {
80    const obj = await this.env.BUCKET.get(file.key);
81    return processData(await obj.arrayBuffer());
82  });
83}
84```
85 
86## Multiple Workflows
87 
88```jsonc
89{
90  "workflows": [
91    {"name": "user-onboarding", "binding": "USER_ONBOARDING", "class_name": "UserOnboarding"},
92    {"name": "data-processing", "binding": "DATA_PROCESSING", "class_name": "DataProcessing"}
93  ]
94}
95```
96 
97Each class extends `WorkflowEntrypoint` with its own `Params` type.
98 
99## Cross-Script Bindings
100 
101Worker A defines workflow. Worker B calls it by adding `script_name`:
102 
103```jsonc
104// Worker B (caller)
105{
106  "workflows": [{
107    "name": "billing-workflow",
108    "binding": "BILLING",
109    "script_name": "billing-worker"  // Points to Worker A
110  }]
111}
112```
113 
114## Bindings
115 
116Workflows access Cloudflare bindings via `this.env`:
117 
118```typescript
119type Env = {
120  MY_WORKFLOW: Workflow;
121  KV: KVNamespace;
122  DB: D1Database;
123  BUCKET: R2Bucket;
124  AI: Ai;
125  VECTORIZE: VectorizeIndex;
126};
127 
128await step.do('use bindings', async () => {
129  const kv = await this.env.KV.get('key');
130  const db = await this.env.DB.prepare('SELECT * FROM users').first();
131  const file = await this.env.BUCKET.get('file.txt');
132  const ai = await this.env.AI.run('@cf/meta/llama-2-7b-chat-int8', { prompt: 'Hi' });
133});
134```
135 
136## Pages Functions Binding
137 
138Pages Functions can trigger Workflows via service bindings:
139 
140```typescript
141// functions/_middleware.ts
142export const onRequest: PagesFunction<Env> = async ({ env, request }) => {
143  const instance = await env.MY_WORKFLOW.create({
144    params: { url: request.url }
145  });
146  return new Response(`Started ${instance.id}`);
147};
148```
149 
150Configure in wrangler.jsonc under `service_bindings`.
151 
152See: [api.md](./api.md), [patterns.md](./patterns.md)
153