n8n-nodes-letmepost

n8n-nodes-letmepost

This is an n8n community node. It lets you publish to social media platforms with letmepost.dev in your n8n workflows.

letmepost.dev is an open-source social media publishing API for developers and agents. One endpoint publishes to Bluesky, X/Twitter, LinkedIn, Instagram, Threads, Facebook, Pinterest, and TikTok — with preflight validation that catches platform-specific problems before they fail, and transparent, structured errors when a platform rejects a post.

n8n is a fair-code licensed workflow automation platform.

Installation Operations Credentials Compatibility Usage Resources Version history

Installation

Follow the installation guide in the n8n community nodes documentation. Install the package n8n-nodes-letmepost.

Operations

This package ships two nodes.

Letmepost

Resource	Operation	Description
Post	Publish	Create and publish a post to one or more connected accounts. Returns the per-target result, including any preflight warnings or rejections.
Post	Get	Retrieve a single post and its attempt history.
Post	Get Many	Retrieve many posts, filtered by profile, platform, status, or error code.
Account	Get Many	List the social accounts connected to your organization.
Media	Get Many	List previously uploaded media assets.

When publishing, you can attach media by public URL, by an existing letmepost media ID, or directly from a binary property on the incoming item (sent inline). Set an Idempotency Key to make retries safe — reusing the same key never publishes twice.

To reply to a Bluesky post, expand Bluesky Reply (targets a Bluesky account) and provide the parent post's strong ref from a prior publish response: Reply To URI and Reply To CID (both required, sent together). For replies deeper than the first, also set Thread Root URI and Thread Root CID (both required together); omit them to reply to a top-level post and the root defaults to the parent.

Letmepost Trigger

Starts a workflow when letmepost.dev sends a webhook event (for example post.published or post.failed). When the workflow is activated, the trigger registers a webhook endpoint with letmepost.dev automatically and verifies the HMAC signature on every delivery; deactivating the workflow removes the endpoint. Leave Events empty to receive all events, or select specific ones.

Credentials

You need a letmepost.dev account and an API key.

• Sign in to the letmepost.dev dashboard.
• Go to Settings → API Keys and create a key. Use an lmp_live_ key for production or lmp_test_ for the test environment.
• In n8n, create new Letmepost API credentials and paste the key.

The credential also has a Base URL field. Leave it as https://api.letmepost.dev unless you run a self-hosted instance, in which case point it at your own API.

Compatibility

Tested against n8n 1.x. Requires an n8n version that supports community node tools (usableAsTool). No external runtime dependencies.

Usage

• Publish to several platforms at once: select multiple accounts in one Publish operation. The same text and media are sent to every selected account; the response lists the result per target so you can branch on partial failures.
• React to delivery outcomes: pair the Letmepost Trigger with the action node — for example, post to Slack when a post.failed event arrives, including the transparent error from the event payload.
• Idempotent retries: set an Idempotency Key (e.g. an expression derived from the upstream item) so a re-run of the workflow does not double-publish.

For more on building workflows, see the n8n Try it out guide.

Resources

• n8n community nodes documentation
• letmepost.dev documentation
• letmepost.dev on GitHub

Version history

0.1.0

Initial release. Letmepost node (Post: Publish / Get / Get Many; Account: Get Many; Media: Get Many) and Letmepost Trigger (auto-registering webhook trigger with HMAC verification).