postsider

PostSider plugin for Hermes Agent

Your own social media calendar inside Hermes Agent,
through the hosted PostSider MCP server. Plan, draft, schedule, publish and review
posts on 30+ networks, and let a human approve what goes live.

Ask things like:

• "Draft a LinkedIn and X post about our release and put it in the next free slot."
• "What is scheduled for the next 14 days? Which posts failed, and why?"
• "Attach this image to the draft and send it for approval."
• "How did last month's posts perform on Instagram?"
• "Give me the morning check: errors, stuck posts, channels that need a reconnect."

What is in this package

This is an Agent Plugins v1 package with configuration only, no code:

• plugin.json: the manifest. It marks the server untrusted, so Hermes asks before every tool the
  server does not mark read-only.
• mcp.json: one MCP server, postsider, that runs the pinned
  mcp-remote@0.15.2 through npx and connects it to
  https://mcp.postsider.com/mcp with OAuth sign-in.
• skills/postsider/SKILL.md: how to use the tools well (draft first, read back every write, confirm
  before anything public or permanent).

Install

hermes plugins install postsider --enable

Or straight from this repository:

hermes plugins install https://github.com/lumizone/postsider-agent-plugin.git --enable

Requirements: Hermes Agent 0.21.6 or newer, Node.js 20.18.1 or newer with npx on the PATH, and a
PostSider account (7-day trial, no credit card: https://app.postsider.com/register).

Sign in

The first time Hermes connects to the server, mcp-remote opens your browser on the PostSider sign-in
page. Sign in and approve the requested access (read posts, write posts, manage channels). The channels
you connected in PostSider are the ones the agent can see.

Hermes waits about a minute for a new MCP connection. If you need longer to sign in (a new account,
two-factor authentication), the attempt is dropped and the next use opens the sign-in page again.
Creating the account first at https://app.postsider.com/register avoids that, and so does letting Hermes
run the sign-in itself. Hermes's own OAuth client then replaces this package's mcp-remote server, and
the skill keeps working:

hermes mcp add postsider --url https://mcp.postsider.com/mcp --auth oauth

On a headless machine, use an organization API key in a header instead (an entry in config.yaml
replaces this package's server). Create the key in PostSider under Settings, then API:

# ~/.hermes/config.yaml
mcp_servers:
  postsider:
    url: "https://mcp.postsider.com/mcp"
    headers:
      Authorization: "Bearer <your PostSider token>"

Plans

PostSider starts with a 7-day trial and no credit card. Paid plans start at $20 a month per organization
and include MCP, API and webhook access on every tier. Details: https://postsider.com/pricing/

Disclosure

• Network: every tool call goes to PostSider's hosted server (mcp.postsider.com), which acts on the
  user's own PostSider workspace and, when posts go out, calls the connected social networks with the
  channel connections the user made in PostSider. Tool arguments and results, including post text and
  media, are handled by PostSider as part of the user's account. See the privacy policy below.
• Remote tool set: the tools are served by that server at runtime. The pinned commit of this
  package covers the configuration and skill only, not the server's code, and the server can add or
  change tools.
• Writes and external effects: the server can create, edit, schedule and delete posts, and a post
  created with type now or schedule is published to public social media accounts. It can also upload
  and delete media, change channel settings and posting slots, connect or disconnect channels, pause
  publishing for the whole organization, and run PostSider's AI checker and caption rewrite. The package
  marks the server untrusted, so Hermes asks before each tool the server does not annotate as read-only
  and refuses those tools in unattended runs such as cron jobs. The bundled skill tells the agent to
  default to drafts and to confirm exact text, channels and timing before anything goes live.
• Usage limits and cost: actions count toward the user's PostSider plan (posts per month, channels
  and a monthly allowance for the AI checker and caption rewrite).
• Local process and credentials: npx downloads and runs mcp-remote@0.15.2 from npm. On first
  use it starts a local callback server on a localhost port, opens the browser, and stores the OAuth
  tokens for PostSider under ~/.mcp-auth. Without a stored token, an unattended run fails when
  Hermes's connect timeout expires (about a minute) instead of hanging.
• No telemetry from this package, no bundled credentials, no background processes beyond the MCP
  server process Hermes starts, no self-updater.

Privacy policy: https://postsider.com/privacy/ · Terms: https://postsider.com/terms/ ·
Contact: lukasz@postsider.com

License

MIT for the contents of this repository. PostSider itself is a hosted service.

README from the reviewed commit 4ddb64a; it updates when the author re-pins.