Every code block receives input (array from previous step) and must return an array (for the next step).
The Basics
// input: records from previous step
// return: records for next step
return input.map(record => ({
...record,
processed: true,
}));
| Scenario | What’s in input |
|---|
| First step | [] or trigger data |
| After company discovery | Company objects |
| After people search | Person objects |
| After contact enrichment | Contact objects with emails/phones |
return
| Pattern | Code |
|---|
| Transform | return input.map(r => ({ ...r, new_field: "value" })) |
| Filter | return input.filter(r => r.employee_count > 50) |
| New data | return await canvas.companies.find({...}) |
| Passthrough | return input |
- Must return an array
return [] stops the flow- No return = passthrough
Common Patterns
Add fields to each record
return input.map(record => ({
...record,
tier: record.employee_count > 500 ? "Enterprise" : "SMB",
}));
Enrich with AI
for (const record of input) {
record.summary = await canvas.ai.research({
prompt: "Summarize this company",
data: record,
});
}
return input;
return input
.filter(r => r.industry === "SaaS")
.map(r => ({ ...r, priority: "high" }));
Execution Environment
Not allowed: fetch(), require(), import, eval(), file system, env vars
Available: All canvas.* methods, async/await, ES2020+ JavaScript, 30s timeout
