Hermes Agent: Create and Publish Social Posts

Hermes Agent is a good fit for social media work because it is built to keep running: it remembers, it learns skills, and it can sit on a server and answer you through a messaging app. Give it a media generator and a publishing tool, and it can go from “post about the new menu” to a drafted Instagram post with a generated photo.

The flow is the same one I describe in the Claude guide. What is different with Hermes is that you configure it in YAML, it may run where no browser exists, and it lets you filter tools per server, which is the best safety feature of the lot.

Three MCP servers in config.yaml

Hermes reads MCP servers from the mcp_servers map in ~/.hermes/config.yaml. Remote servers take a url, plus either auth: oauth or headers.

On a laptop or desktop, use OAuth for all three. No keys in files:

mcp_servers:
  postsider:
    url: https://mcp.postsider.com/mcp
    auth: oauth
  fal:
    url: https://mcp.fal.ai/mcp-relay
    auth: oauth
  higgsfield:
    url: https://mcp.higgsfield.ai/mcp
    auth: oauth

Then sign in to each once:

hermes mcp login postsider
hermes mcp login fal
hermes mcp login higgsfield

The same can be done from the CLI with hermes mcp add --url https://mcp.postsider.com/mcp --auth oauth postsider, according to the Hermes MCP docs. Tokens land in ~/.hermes/mcp-tokens/. Keep only one of the two generators if you like; for Higgsfield, its help center also offers a CLI that Hermes can install as a skill.

On a headless server, use keys from the environment

A VPS has no browser to finish an OAuth login. For PostSider and fal, switch to their key-based endpoints and read the keys from environment variables.

mcp_servers:
  postsider:
    url: https://api.postsider.com/mcp
    headers:
      Authorization: "Bearer ${POSTSIDER_API_KEY}"
  fal:
    url: https://mcp.fal.ai/mcp
    headers:
      Authorization: "Bearer ${FAL_KEY}"

The PostSider key comes from Settings, then Developers, then Public API. It can publish to every connected account, so treat it like a password: environment variable or secrets manager, never a committed file. Hermes also documents a device-code OAuth flow for headless gateways, which is worth trying with services that support it.

Filter out the tools a social media agent never needs

This is where Hermes is better than most clients. Each MCP server can take a tools block with include or exclude, so dangerous tools never reach the model at all.

PostSider exposes a full workspace toolset, including deleting posts, pausing all publishing and disconnecting channels. A content agent needs none of those. Hide them:

mcp_servers:
  postsider:
    url: https://mcp.postsider.com/mcp
    auth: oauth
    tools:
      exclude:
        - postsider_delete_post
        - postsider_delete_media
        - postsider_pause_publishing
        - postsider_disconnect_channel

A confirmation prompt can be clicked through at 11 pm. A tool the agent cannot see cannot be called. For an unattended Hermes, I would go one step further and use include with only the tools the flow below needs.

The seven-step flow Hermes runs

Every post goes through the same calls. Hermes can learn the sequence as a skill, so after the first run you just say “make Thursday’s post”.

In words:

1. Brief. What the post is about, which networks, when.
2. Generate. fal.ai or Higgsfield returns a URL to the finished file.
3. Review. You look at it. If you talk to Hermes from a messaging app, it can send you the link to check on your phone.
4. Store. postsider_upload_media_from_url copies the file into PostSider and returns an id and path. Do not skip this: generator links are temporary, and fal’s results come with a note that source URLs may expire.
5. Rules. postsider_get_channel_rules returns what each network requires: post_type on Instagram, a privacy level on TikTok, a title on YouTube, who_can_reply_post on X.
6. Draft. postsider_create_post with type: draft and the stored media in images. Add an idempotencyKey, so a retry after a timeout cannot create a second post.
7. Read back. postsider_get_post confirms what was saved.

For file limits (images up to 10 MB, MP4 up to 500 MB) and a fal.ai cost chart, see the Claude guide.

A brief Hermes understands

Hermes works best with a clear, reusable instruction. After the first good run, ask it to save the steps as a skill so the next brief can be one line.

For each post in this list, generate one 4:5 image with fal.ai
(1080x1350, black and white, soft light, no text in the image).
Send me the image links and wait for "ok" or "redo N".
For approved images: store them in PostSider, check the rules for
Instagram and LinkedIn, find the next free slot for each channel,
and create DRAFTS with an idempotency key per post.
Read every draft back and send me a short summary.
Then save this procedure as a skill called "weekly-social-drafts".

POSTS:
1. TOPIC A
2. TOPIC B
3. TOPIC C

Two notes from experience with agents in general. First, 4:5 at 1080x1350 can come back as 1072x1344, because many image models round to multiples of 16; it is still 4:5 and Instagram accepts it. Second, TikTok is direct posting in PostSider, so a scheduled TikTok post goes live when it fires. Let Hermes draft TikTok posts, never schedule them on its own.

Start with one draft

Add the three servers, run hermes mcp login, exclude the destructive tools, and get one draft with a generated image into your calendar. Then turn it into a skill.

You can start with PostSider for free and connect your first social media account in a few minutes. The full tool list is in the PostSider MCP docs.