# StableDesign Reply to Comment

> StableDesign Reply to Comment is a paid API for AI agents from stabledesign.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-11).

Post a reply to a comment on a Canva design via the StableDesign API, paid per call with USDC micropayments.

## Facts

- Endpoint: POST https://stabledesign.vercel.app/api/comments/reply?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stabledesign-reply-to-comment-305c298a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_API-h4q0hbzKRXtOerjXS

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stabledesign-reply-to-comment-305c298a -d '<json body>'
```

Example prompt: Reply to the comment with ID 'cmt_abc123' on my StableDesign project saying 'Thanks for the feedback — I've updated the font as requested!' and pay the $0.01 USDC call fee.

## When to prefer this

Use this endpoint when you need to programmatically reply to an existing comment on a Canva design managed through StableDesign, especially in agentic workflows where design review feedback must be acknowledged or responded to automatically with pay-per-call micropayment billing via x402.

## Known failure modes

- Comment ID not found — returns 404 with error indicating invalid or missing comment
- Design not accessible — returns 403 if the authenticated user lacks permission to comment
- Invalid reply body — returns 400 if reply text is empty or malformed
- Payment failure — returns 402 if the x402 USDC micropayment is not fulfilled or insufficient
- Rate limit exceeded — returns 429 if too many calls made in a short window
- Canva backend unavailable — returns 502/503 if the underlying Canva API is down

## How this service works

Pay-per-call Canva design API via MPP micropayments. Create, list, export designs and upload assets.

## Output

Returns a reply object confirming the comment reply was posted, including the reply ID, timestamp, parent comment ID, and reply body text within the design's comment thread.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "message": {
   "type": "string",
   "minLength": 1
  },
  "design_id": {
   "type": "string",
   "minLength": 1
  },
  "thread_id": {
   "type": "string",
   "minLength": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stabledesign-reply-to-comment-305c298a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stabledesign.vercel.app](https://www.zero.xyz/host/stabledesign.vercel.app/llms.txt)