API reference · Engaging
Reply to a comment
POST /v1/comments/{id}/replies
Answer a comment someone left, by that comment's id (from GET /v1/posts/{id}/comments). Distinct from publishing: this acts on someone else's content. Free everywhere except X, where a reply is billed as a post.
Request
Authenticate with a bearer API key. Agents calling over MCP authorise with OAuth instead and never handle the key.
curl -X POST https://api.postlake.dev/v1/comments/{id}/replies \
-H "Authorization: Bearer $POSTLAKE_API_KEY" \
-H "Content-Type: application/json" \
-d '{"account":"…","text":"…"}'Parameters
| Field | Type | Required | What it is |
|---|---|---|---|
id | string | Yes | In the URL. The comment id |
Body
| Field | Type | Required | What it is |
|---|---|---|---|
account | string | Yes | The connected account id (acc_…) replying |
text | string | Yes | The reply |
Response
Posted (200).
| Field | Type | Required | What it is |
|---|---|---|---|
account | string | No | |
platform | string | No | |
id | string | No | |
ok | boolean | No |
Example
{
"account": "…",
"platform": "…",
"id": "…",
"ok": false
}Limits
Write operations are limited per account, and rate-limit responses include Retry-After. Do not automatically retry a write unless this operation explicitly documents idempotency.
Calling this from an agent
Agents do not call REST. They call tools. Over the hosted MCP server this operation is read_comments, and the agent authorises with OAuth so your API key is never pasted into a chat or seen by the model. The reply comes back in the same normalised shape you see above, which is what lets an agent reason about it without a per-network branch.
You control what any one agent may do with it: which brands it may act for, which networks it may reach, how much it may do in a day, and whether it may spend credits you bought up front. See the MCP server.
Errors
Every failure uses one shape: a stable type, a granular code, the field at fault in param, and a plain-language fix. An agent can act on it without a person reading the message. See Errors and retries.
Idempotency-Key.Common questions
Can an AI agent do this without the REST API?
Yes. Over MCP the same job is the read_comments tool. The agent authorises with OAuth, so no API key is pasted into a chat or seen by the model, and the answer comes back in the same normalised shape.
Is it safe to retry this call?
Do not automatically repeat a write after a timeout unless that endpoint explicitly documents idempotency. First read the resulting state; a second request could repeat the action.
What happens when it fails?
You get one error shape: a stable type, a granular code you can branch on, the offending field in param, and a fix written so an agent can correct itself rather than stop. Full list on Errors and retries.