Post to Facebook, Instagram or Threads
post_to_metaPublish to connected Meta channels—Facebook Page, Instagram, or Threads—with text, images, video, carousels, collabs, and scheduling.
Instructions
Publish to a connected Facebook Page, its linked Instagram, OR the brand’s Threads account — text/link/image/VIDEO/CAROUSEL. A MULTI-SLIDE creative is a CAROUSEL, not several posts: pass the slides in order as imageUrls[] and they publish as ONE swipeable post (Instagram album, Threads carousel, Facebook multi-photo post). Never publish slide 1 of a deck on its own — the creative tells the viewer to swipe. target:"facebook" (default) posts to the Page; target:"instagram" publishes a photo or Reel to the linked IG business account (needs an image or video); target:"threads" posts to the connected Threads account (text, image, or video). Works with ANY media — a finished Hermoso ad OR an arbitrary user file: imageUrl/videoUrl accept a public https URL, a data: URI, or a Hermoso /generated path; for a LOCAL file (e.g. on the user’s desktop) call upload_file first and pass the url it returns. INSTAGRAM COLLAB: pass collaborators (up to 3 usernames) to invite other accounts to CO-AUTHOR the post — it then shows on their profile too once they accept, which is the reach play behind every creator partnership. This PUBLISHES immediately — confirm the copy + media with the user first. Needs a connected Meta account (Settings ▸ Connectors ▸ Meta) with posting permission; Threads needs its own connection.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| hook | No | WHAT ANGLE THIS POST IS BUILT ON — the single most valuable field here, and the only moment it can ever be recorded. post_performance groups on it to answer "which hooks work", and it needs 5 posts sharing ONE hook before it will call anything a winner, so REUSE THE SAME WORDING across a campaign instead of rephrasing it every time. Best of all, pass a hook id from list_hooks (e.g. "direct_callout", "mid_problem", "before_after") — those fold onto a stable key however they are spelled, so a whole brand accumulates evidence on one row. Your own wording is fine too; it just only groups when you repeat it exactly. Omitting it means this post can never vote on which hook works. | |
| link | No | a URL to attach (FB text post only) | |
| async | No | publish in the BACKGROUND and return a job id to poll with get_job, instead of waiting. USE THIS FOR VIDEO: a Facebook or Instagram video publish routinely outlives an agent transport, and a timeout on the synchronous path leaves you unable to tell whether the post is live. With async:true nothing can time out — the job reports the post id and url when it lands. | |
| pageId | No | target Page id (from list_meta_pages); omit = first Page | |
| target | No | default facebook; instagram → the Page’s linked IG; threads → the brand’s connected Threads account | |
| account | No | WHICH Instagram account when target is instagram and the brand has several — Page-linked and Instagram Login accounts alike; an @username or id from list_connector_accounts("instagram"). Several and none named is refused by name; omit when there is one. | |
| altText | No | ACCESSIBILITY — the description screen readers announce, and what the platform otherwise auto-generates badly or not at all. Describe what is actually IN the picture, never the caption. ONE STRING describes the picture; on a CAROUSEL it describes EVERY slide. Pass an ARRAY of strings instead to describe each slide separately, aligned to the slide order — that is strictly better on a multi-slide post, because one sentence read out over six different pictures is wrong for five of them. More descriptions than pictures is refused rather than dropped. WHERE IT LANDS, per Meta’s own docs: INSTAGRAM image posts and the IMAGE slides of an Instagram carousel (up to 1000 characters; dropped rather than sent on a Reel or a video slide, which Meta do not support); FACEBOOK Page photos including every photo of an album, via alt_text_custom (Meta publish no length for it, so nothing is truncated); THREADS on a single-image or single-video post ONLY — Meta document no way to attach alt text to a Threads CAROUSEL slide, so a Threads carousel publishes undescribed and the reply says so rather than risking the whole post on a guess. (AI disclosure is separate and automatic — every Instagram post Hermoso publishes is flagged is_ai_generated, which is not a caller setting.) | |
| message | No | post text / caption | |
| subject | No | WHAT THIS POST IS ABOUT — the product, feature, offer or theme (e.g. "winter coat", "free trial", "founder story"). The second grouping axis in post_performance. Same rule as hook: reuse the exact wording so posts about one subject land in one group. | |
| imageUrl | No | public https URL, a data: URI, or a Hermoso /generated path (upload_file gives you one for a local file) | |
| topicTag | No | THREADS ONLY — one topic tag for discovery, 1–50 characters. A leading # is stripped for you; Threads refuses "." and "&". | |
| videoUrl | No | public https URL, data: URI, or /generated path — FB video post / IG Reel | |
| imageUrls | No | CAROUSEL — an ORDERED list of image (and, where the channel allows, video) URLs published as ONE post the viewer swipes through. THIS IS NOT “post several” — it is a single post with several slides, which is what a multi-slide creative (a listicle, a “1/6 · SWIPE” deck) actually needs; publishing only its first slide tells the viewer to swipe at something that cannot. The ORDER is the product. Limits per channel: Instagram 2–10 (images, videos or a mix), Threads 2–20 (mix allowed), Facebook 2+ (Meta publishes no documented maximum; Hermoso caps the upload fan-out at 30 and says so), LinkedIn company Pages 2–20 (images only), Pinterest 2–5 (images only), TikTok up to 35. One url here is simply an ordinary single post. Anything a channel cannot do is REFUSED with the real reason — nothing is ever quietly downgraded to one slide. | |
| trialReel | No | INSTAGRAM TRIAL REEL — publish this Reel to NON-FOLLOWERS ONLY at first, so a hook can be tested on a cold audience without spending it on the people who already follow the brand. Instagram then shows it to followers only if it graduates. MANUAL = the creator graduates it by hand in the Instagram app; SS_PERFORMANCE = Instagram graduates it automatically if it performs well. REELS ONLY and INSTAGRAM ONLY: an image, a carousel, a Facebook post or a Threads post is REFUSED BY NAME rather than quietly published as an ordinary post — a trial that silently goes to every follower is the exact opposite of what was asked for. Omit it for a normal Reel. | |
| locationId | No | Threads only — a place id from search_threads_locations, to geotag the post to a physical location (restaurant, storefront) | |
| scheduleAt | No | FACEBOOK ONLY — schedule instead of posting now. ISO timestamp (2026-08-01T09:00:00Z) or unix seconds; must be 10 minutes to 30 days ahead. Facebook holds the post and publishes it at that time, so nothing has to stay running on our side. Instagram and Threads have NO scheduling in Meta’s API — passing this for them is refused rather than silently posted immediately. | |
| productTags | No | INSTAGRAM SHOPPING — make the post SHOPPABLE by tagging products from the brand’s own catalog; tapping a tag opens the product’s price sheet inside Instagram. Instagram only. ON A PHOTO each tag is {product_id, x, y}, where x and y are FRACTIONS of the image from 0.0 (left/top) to 1.0 (right/bottom) — 0.5,0.5 is the middle — and BOTH are required, max 20. ON A REEL it is {product_id} ALONE with no coordinates, max 30. ON A CAROUSEL it is an array PER SLIDE ([[{…}], [], [{…}]]) because Instagram tags each slide’s own container, max 5 per slide and 20 across the post. Ids come from search_instagram_shopping_products; call list_instagram_shopping_catalogs FIRST, because tagging needs an APPROVED Instagram Shop and without one this fails after the media is already uploaded. A tag whose product is not “approved” is stored and shown to nobody. | |
| quotePostId | No | THREADS ONLY — the id of a post to QUOTE. A quote post is a distinct post type, not a formatting option. | |
| countryCodes | No | THREADS ONLY — restrict the post to these ISO 3166-1 alpha-2 countries. ⚠ This is an ALLOWLIST, so the post becomes INVISIBLE in every country not named — it narrows reach, it does not target. | |
| replyControl | No | THREADS ONLY — who may reply. Default is everyone. | |
| collaborators | No | INSTAGRAM COLLAB — up to 3 Instagram usernames invited to CO-AUTHOR this post. Once one accepts, the post appears on THEIR profile too, with both handles in the header and the likes and comments shared — it is how a brand reaches a creator’s audience without paying for placement, and it is the single most-asked thing a scheduler normally cannot do. Pass handles only ("hermosoai"), not profile links; a leading @ is fine. INSTAGRAM ONLY — Facebook and Threads have no collab post at all and are refused BY NAME rather than silently dropping the co-authors — and never on a Story. AN INVITE IS NOT A CO-POST: publishing SENDS a request the other account must accept in their Instagram notifications, and until they do the post is on this brand’s profile ALONE; they may also decline, and Instagram sends no notification either way. So never report the post as live on both accounts — read the invite status back out of the reply, and use instagram_collaborators later to find out whether they accepted. | |
| allowDuplicate | No | post it even though an identical post was just made or attempted. Only pass this when the user genuinely wants the same thing posted twice, or when you have LOOKED at the account and confirmed a timed-out attempt did not land. | |
| idempotencyKey | No | SAFE RETRIES. Publishing can take minutes (a video upload, a carousel of ten slides) and a transport can time out while the post SUCCEEDS — retrying blind is how the same thing gets posted twice. Pass any stable string here and a repeat of the SAME publish returns the ORIGINAL post id instead of posting again (24h). You do not have to: an identical publish is auto-recognised for 10 minutes anyway. If a call times out or errors ambiguously, CALL AGAIN WITH THE SAME KEY — that is the safe move, and it will either report the original post or publish it for the first time. It never posts twice. | |
| linkAttachment | No | THREADS TEXT POSTS ONLY — a full http(s) URL rendered as a clickable link card. This is how a Threads post carries a destination at all; without it a link is just text. Meta allows at most 5 links per post and refuses a link attachment on a post that also carries an image or video, so Hermoso refuses that combination up front rather than letting Meta silently drop it. | |
| crossreshareToIg | No | THREADS ONLY — ALSO share this Threads post to the linked Instagram account AS A STORY (not a feed post), in the same publish. NOT available on a Threads CAROUSEL, which is refused by name rather than silently dropped. THERE IS NO CONFIRMATION: Threads returns no field saying whether the Story was created, so report it as REQUESTED and tell the user to check their Instagram Stories — never that it is live. | |
| crossreshareDarkMode | No | THREADS ONLY — render that Instagram Story in dark mode. Only meaningful alongside crossreshareToIg; on its own it is refused rather than silently ignored, because a parameter that never reaches the wire must not look accepted. |