---
title: "Lemmy API: post and schedule from code"
url: "https://get1post.com/developers/lemmy.md"
canonical_url: "https://get1post.com/developers/lemmy"
last_updated: "2026-10-26"
type: "reference"
summary: "Post and schedule to Lemmy with the 1Post API and MCP server: the request, the reply, every rule it is checked against and a dry run."
related: ["https://get1post.com/platforms/lemmy.md", "https://get1post.com/platforms/lemmy/specs.md", "https://get1post.com/docs/api-posts.md", "https://get1post.com/docs/mcp.md"]
---

# Lemmy API: post and schedule from code

Post and schedule to Lemmy with the 1Post API and MCP server: the request, the reply, every rule it is checked against and a dry run.

Post to Lemmy from code with one request: POST /v1/posts with your account id, the text and a schedule_at time. Lemmy text is limited to 10,000 characters, counted by code points. 1Post allows up to 20 posts a day for each connected account, and a dry run checks a post against every rule first.

## Connect Lemmy first

1. Open Accounts in 1Post and choose Connect, then Lemmy.
2. Enter your instance address, username and password. They are stored encrypted.
3. Choose the communities in the composer.

Then GET /v1/accounts returns the id of the Lemmy account to use in the request.

## Send a post to Lemmy

**Schedule a post**

```bash
curl https://api.get1post.com/v1/posts \
  -H "Authorization: Bearer $ONEPOST_API_KEY" \
  -H "Idempotency-Key: lemmy-first-post" \
  -d '{"accounts":["ACCOUNT_ID"],"text":"Weekly thread: what are you building?","schedule_at":"2026-11-02T15:00:00Z"}'
```

The reply is 202 with the post (status scheduled) and one destination for Lemmy, which moves from queued to published or failed.

## What you can send to Lemmy

- Text or link post with a thumbnail
- One or more communities
- Comment

## Lemmy rules the request is checked against

| Rule | What 1Post checks |
| --- | --- |
| Text limit | 10,000 characters, counted by code points |
| Media accepted | Images |
| Images per post | 1 |
| Threads | No |
| First comment | Yes |
| Posts per day, per connected account (1Post) | 20 |

The same table with sources is on the [Lemmy specs page](https://get1post.com/platforms/lemmy/specs.md).

## Lemmy options in the request

- First comment: add first_comment with text to an account object, and delay_min if it should wait.

## Check the post before it is queued

Add "dry_run": true to test a post: nothing is kept, a valid one answers 200 and a broken one answers 422 naming the rule.

**A refused request, abridged**

```json
{
  "error": {
    "code": "invalid_for_platform",
    "message": "lemmy refuses this post: Lemmy counts 10,032 of 10,000 characters in part 1. (text_too_long).",
    "fix": "Fix the rule named in the message and send the post again.",
    "retryable": false,
    "request_id": "REQUEST_ID"
  }
}
```

An assistant connected to the [MCP server](https://get1post.com/docs/mcp.md) sends the same fields to create_post; [set one up](https://get1post.com/assistants.md).

## Questions

**Can I post to Lemmy with an API key?**

Yes. A key with write scope can create, change and cancel Lemmy posts for the workspace it belongs to, with the role of the member who made it. See [API authentication](https://get1post.com/docs/api-authentication.md).

**What happens if a Lemmy post breaks a rule?**

The request is refused with invalid_for_platform and the failing rule is named. Fix it and send the request again, or send it with dry_run to test the fix first.

**How many Lemmy posts can I send in a day?**

Up to 20 for each connected account. A request that would pass that answers daily_cap with the time the day frees up.

## Related

- [Schedule Lemmy posts: formats, limits, setup](https://get1post.com/platforms/lemmy.md)
- [Lemmy specs and limits: text, media, daily cap](https://get1post.com/platforms/lemmy/specs.md)
- [Creating and changing posts with the API: 1Post docs](https://get1post.com/docs/api-posts.md)
- [The MCP server: 1Post docs](https://get1post.com/docs/mcp.md)