Automated Multi-Image Posting to Bluesky Social - n8n Workflow

Social Media Managers who need to cross-post dynamic content reliably.
Content Creators seeking advanced, automated distribution methods.
Developers and power users looking for a robust n8n workflow example for complex native API interactions.
Users who require custom social media posting functionality not offered by standard n8n node connectors.

The official Bluesky API requires specific steps for handling multi-image posts, including separate session creation, individual image blob uploads, and careful structuring of the final post payload. This n8n workflow simplifies this complex process. By utilizing core n8n node types like HTTP Request, Split Out, and Aggregate, this automation provides a ready-to-use n8n template that manages the entire lifecycle: from defining credentials and caption text to downloading images, uploading them as blobs, and finally creating the feed post. This ensures your content is published correctly without manual API coding, providing a powerful piece of social media automation using the n8n platform.

This powerful n8n workflow starts with a manual n8n trigger, designed for immediate testing and execution.

1. Authentication Setup: The flow first runs through the Define Credentials n8n node, which feeds the Bluesky identifier and app password into the Create Bluesky Session HTTP Request n8n node. This returns the crucial accessJwt and did needed for subsequent steps.


2. Content Definition: Simultaneously, the post caption is defined in the Set Caption n8n node, and the image URLs (up to 4) are defined in the Set Images n8n node.


3. Image Processing: The Split Out n8n node separates the list of image URLs into individual items, allowing parallel processing. Each item then uses a dedicated Download Images HTTP Request n8n node to fetch the binary image data.


4. Image Upload (Blob): The downloaded binary data for each item is uploaded using the Post Image to Bluesky HTTP Request n8n node to the /uploadBlob endpoint, using the JWT for authorization.


5. Data Formatting and Aggregation: The Code n8n node reformats the response from the upload (the image blob reference) into the specific structure required for the Bluesky embed object. The Aggregate n8n node then collects all individual image data structures back into a single array.


6. Final Posting: Finally, the Post to Bluesky HTTP Request n8n node sends the complete post payload, including the post text (from Set Caption) and the aggregated image array, to the createRecord endpoint, completing the n8n workflow.

To use this n8n template, follow these steps:

1. Import: Copy the provided JSON and import it into your n8n instance via the 'Workflows' menu.


2. Bluesky Credentials: Before running the n8n workflow, navigate to the Define Credentials n8n node. Update the placeholder values (username.bsky.social and XXXX-YYYY-ZZZZ-XXXX) with your actual Bluesky username (identifier) and the generated App Password (required for API access).


3. Post Customization: Modify the Set Caption n8n node to define your desired post text (max 300 characters).


4. Image Links: Update the Set Images n8n node with the URLs of the images you wish to post (up to 4).


5. Execution: Use the manual n8n trigger ('When clicking ‘Test workflow’') to test the process or set up a recurring schedule for full automation.

When clicking ‘Test workflow’ (Manual Trigger):
Function: This manual n8n trigger initiates the entire automation sequence for easy testing and debugging.

Define Credentials (Set):
Function: Stores the static input variables (Bluesky identifier and app password) securely for use in the subsequent authentication HTTP Request n8n node.
Key Configuration: Raw JSON mode is used to define identifier and password keys.

Create Bluesky Session (HTTP Request):
Function: Handles the initial user authentication with the Bluesky API to obtain a session token (accessJwt) and User DID, essential for subsequent authorized API calls.
Key Configuration: URL is set to https://bsky.social/xrpc/com.atproto.server.createSession. The request body uses JSON expression referencing the credentials defined in the previous n8n node.

Split Out:
Function: This crucial n8n node takes the array of image URLs and splits them into individual data items, preparing them for sequential downloading and uploading.
Key Configuration: Splits out the photos field.

Download Images (HTTP Request):
Function: Retrieves the actual image file content from the provided URL, fetching the binary data necessary for the blob upload step.

Post Image to Bluesky (HTTP Request):
Function: Uploads the binary image data as a 'blob' to the Bluesky server. This is a prerequisite for embedding the image in the final post.
Key Configuration: Content Type is set to binaryData, and the Authorization header uses the JWT retrieved earlier in the n8n workflow.

Code (Code):
Function: Transforms the output data structure from the image blob upload into the correct JSON format required by the Bluesky embed.images array, adding a placeholder alt text.

Aggregate:
Function: Collects all individually formatted image blob items back into a single array before they are used in the final Post to Bluesky n8n node.

Post to Bluesky (HTTP Request):
Function: Executes the final API call to create the public post record, combining the user DID, text caption, and the aggregated image embeds. This is the final action of this n8n workflow.
Key Configuration: The request body is a complex JSON object containing expressions for the user DID, text, timestamp, and the embedded images array.