Posting to social media with Antwork

Antwork is an MCP-native social-media scheduler. Your agent talks to it over MCP and it handles the platform APIs, OAuth tokens, scheduling and publishing.

This skill is self-contained. It codifies the mistakes assistants make against the server, so the post ships correctly the first time.

Setup (once)

The skill needs the Antwork MCP server connected. It is a remote server with OAuth — there is no API key to paste.

mcporter config add antwork --url https://api.antwork.io/mcp --auth oauth

Complete the browser prompt and you are connected. A free account is enough: two connected social accounts, no monthly post limit (each account has a per-platform daily cap over a rolling 24 hours, returned as dailyPostCap by get_post_context), and no plan gate on MCP access. Sign up and connect your social accounts at https://antwork.io.

Other agents (Claude, Claude Code, ChatGPT, Cursor, VS Code, Windsurf, Gemini CLI) have their own setup at https://antwork.io/docs/mcp.

If tool calls fail with an auth error, the OAuth grant expired — re-run the command above.

1. Resolve the workspace and the account first

workspace_id is optional on every tool and auto-resolves when the user has exactly one workspace. If they have several and no default, call set_default_workspace once — do not thread workspace_id through every later call, and do not ask the user the same question every turn.

create_post targets one account via account_id. Call list_social_accounts for the target account's id and check its tokenHealthStatus. If it reads expired or needs_reconnection, stop and surface the reauthUrl — a post against a dead account fails at publish time, not at draft time.

2. Pull context before writing any copy

Call get_post_context(platform, account_id) first. It returns:

• Brand identity — workspace name, website, logo.
• Up to 15 of the account's recent posts, with their engagement. These are the voice: there is no stored voice profile. They also show which themes not to repeat.
• performance, once Antwork has measured some posts: topPosts ranked by the metric that matters on that platform (rankedBy: saves on Instagram, link clicks on Pinterest, watch time on YouTube...) over 90 days, and the account's followers. Weight topics and hooks by what performed.

Match those posts, weighting the ones that performed: pronouns, tone, length, emoji and hashtag habits, recurring vocabulary. Never apply a generic "use I/my" rule — an agency account and a solo founder's account want opposite things, and their posts already show which. If recentPosts is empty there is nothing to imitate, so ask the user once for a few sample posts or their tone rather than guessing.

3. One account per post

There is no platforms or platform_texts argument. create_post writes to a single account_id and the platform is derived from that account.

• One account: one create_post.
• Several accounts: one create_campaign call with a variant per account, each with copy reshaped for that platform. They become separate posts under one campaign. Do not reuse one body across platforms — X's 280 characters mangle LinkedIn copy, and LinkedIn-length paragraphs look broken on Threads. get_post_context(account_ids=[...]) loads every account's voice in one call. Send the set with schedule_post(campaign_id=..., scheduled_for) (same time) or publish_post(campaign_id=...) (now). A campaign covers at most 10 posts; more is refused with too_many_posts.

4. Character limits are enforced server-side

Keep posts short by default. LinkedIn is the one place where 300–600 words is fine. Trim before dispatching — schedule_post and publish_post refuse over-limit text rather than truncating it.

5. Draft then publish — the two-step trap

create_post creates a draft. It does not publish or schedule on its own.

• Schedule for later: create_post → schedule_post(post_id, scheduled_for) with an ISO 8601 time. The workspace block of get_post_context gives the workspace's preferredTimes in its own timezone.
• Publish now: create_post → publish_post(post_id). It waits up to ~25s and returns the live URL.

Always complete the second step when the user said "schedule" or "post it". Reporting "scheduled!" after only create_post is false — the post is sitting in drafts. If they haven't said, offer the choice after the draft: publish now, schedule, or keep as a draft. Their pick is the approval. For a batch, ask once for the set, not per post.

6. Plan before drafting anything multi-post

For a batch, a launch week, or several platforms, present a short numbered plan first — hook, account, and when — and wait for approval before calling create_post. Editing a plan is cheaper than editing five drafts.

7. Media is attached, not created

create_post accepts: text, account_id, hashtags, goal, scheduled_for, campaign_id, user_tags, pinterest_board_id, platform_options, variants, workspace_id. Media is not a create-time field: add it afterwards with add_media, which attaches to every post in attach_to_post_ids in one call. TikTok and YouTube need a video, Instagram and Pinterest an image or video, so ask for media in the same turn as the draft. A local file: add_media(upload={}, attach_to_post_ids=[...]), then one curl -X PUT --data-binary @<file> to the returned uploadUrl (the reply says what was attached). A public URL: add_media(url=..., attach_to_post_ids=[...]). Something already in the library: add_media(media_urls=[...], attach_to_post_ids=[...]). If neither works, give the user the post's mediaUrl from the create_post result: it opens the post in the Antwork composer with the media picker open. TikTok's audience is the user's choice, not yours: point them to the post's settingsUrl. Pass hashtags as a list with no # prefix, and only when the account's own posts use them. The server appends them to the text as #tags (they count toward the character limit), so put them either in text or in hashtags, never both. On YouTube they are video tags instead. A YouTube title goes in platform_options.title.

Do not pass platforms, platform_texts, tags or priority. The server rejects unknown fields.

8. Report results, name failures

publish_post returns success or failure plus the live URL. Report one line per account with the link. On failure, name the platform and quote the error rather than saying "publish failed". publish_post(post_id) on a post that failed mid-publish retries it.

9. Analytics is tabular

get_performance and get_engagement_history (pass post_id for one post) return {schema, rows, rowCount} — you render the table or chart. Metrics refresh every 6 hours on their own, so a post published minutes ago has no numbers yet.

Beyond likes, comments, shares and impressions, rows carry reach, saves, clicks, bookmarks, linkClicks, profileVisits, follows and watchTimeSeconds where the platform reports them. A blank cell means not reported, never zero; awaitingPermission names fields a platform hasn't released yet (Instagram and Threads while Meta reviews Antwork's insights access). impressions means a different quantity per platform (reachBasis), so don't add it across platforms. get_engagement_history also returns a followers table: daily follower counts per account.

10. Confirm destructive operations

delete_post and delete_media are destructive. Confirm with the user first, then report exactly what was removed. Disconnecting a social account is done in the Antwork web app, not through the connector.

Avoid the AI tells

Across every voice, skip openers that read as generated: "Here's the thing:", "Let me break it down", "Buckle up", emoji-stuffed hooks. If the account's own posts avoid em dashes, avoid them.

More

The full toolkit — 8 specialized skills for calendars, campaigns, repurposing, voice, audits and analytics — is MIT-licensed at https://github.com/polynode-co/antwork.