Post to Instagram from Codex

Hermoso is a marketing MCP server: 301 tools over one OAuth’d endpoint that let an agent research the ads already running in a market, generate finished image and video ads, publish them, and build the paid campaigns behind them. Codex reaches all of it through one connection. This page is about one slice of that — what Codex can actually do on Instagram, and what Instagram will not let it do.

Connect Hermoso to Codex

Create an API key. In Hermoso, open Settings → Agents & API keys and press ＋ Create API key. It looks like hmk_… and carries real spend authority, so treat it like a password.

Add it to ~/.codex/config.toml. Codex reads TOML, not JSON — a copied mcpServers block will not load:

[mcp_servers.hermoso]
url = "https://app.hermoso.ai/mcp"
http_headers = { "Authorization" = "Bearer <your key>" }

Ask Codex for something. “Pull my three closest competitors’ longest-running ads and remix the best hook into a 9:16 video,” or “post this render to the channel.” The agent picks the tools; you approve the spend.

The TOML detail is the one that trips people up: every other client in this list takes a JSON mcpServers object, and Codex takes [mcp_servers.<name>] with http_headers.

Then connect Instagram itself, once, under Settings → Connectors in Hermoso. That is an OAuth consent screen, so it is the one step that needs a browser — everything after it is a tool call.

The Instagram tools Codex gets

post_to_meta — publishes to Instagram with target: "instagram". Instagram is a visual channel and the API agrees — a post needs an image or a video.
schedule_post — queues it on the shared calendar, with a per-channel caption if the copy should differ from your Facebook or LinkedIn version.
list_meta_comments / reply_to_meta_comment / moderate_meta_comment — read, reply and moderate under a post.
meta_page_insights / meta_post_insights — reach, impressions, saves and engagement, per account and per post.
search_instagram — keyword search across public Instagram Reels — research, not publishing.

Two Instagram facts worth knowing before you automate anything. There is no native Instagram scheduling in Meta’s API, so a schedule is Hermoso’s queue rather than Instagram’s, and passing Facebook’s scheduleAt for Instagram is refused rather than silently posted now. And an Instagram post cannot be edited or deleted through the API at all — whatever goes out, stays, and has to be removed by hand in the app.

Instagram limits worth knowing before you automate anything

Text	An Instagram caption is capped at 2,200 characters. It is enforced when the post is created or queued — refused while you are still there to fix it, rather than silently cut on the way out.
Visibility	Public only. Meta’s Content Publishing API publishes, full stop — “Instagram publishes immediately when it publishes at all — it has no unlisted, private or draft post.” If you want a review step on Instagram, it has to happen before the call, not after.
Carousel	2 to 10 slides, and images and video may be mixed. That upper bound is Meta’s own, quoted in the capability table it enforces: “Carousels are limited to 10 images, videos, or a mix of the two.” The floor of 2 is ours, because one slide is not a carousel on any platform — a single-slide ask publishes as an ordinary post rather than being refused.
Which account	`pageId` — Instagram publishes through the connected Facebook Page, so the same identity field selects it.

Try it in Codex

Ask for it in ordinary language — these are sentences, not a DSL:

“Non-interactive: build a 4-slide carousel from today's product photos, publish it to Instagram with a caption under 2,200 characters, and exit with the permalink.”

That walks search_instagram → plan_ad → render_ad → post_to_meta (target: "instagram"). Interactively Codex shows the call before it runs it. Non-interactively there is nobody to ask, which is worth designing around on any step that publishes or spends.

Codex on Instagram: the part that bites

Instagram is a poor fit for a fully unattended pipeline for one reason: nothing published can be edited or deleted through the API. If Codex is running on a timer, put the review before the publish — generate and hold, then publish on approval — rather than relying on being able to pull something back afterwards, because you cannot.

For unattended runs, prefer the hermoso CLI with --json over the full tool manifest — it is far cheaper in context and easier to assert on.

Research Instagram before you post

search_meta_ads covers Instagram placements as well as Facebook — it is one library. For organic, search_instagram searches public Reels by keyword, which is the surface where the format actually moves; profile and hashtag pulls go through scrapecreators_fetch.

The paid half

Instagram placements are bought through the same Meta campaign tree as Facebook: create_meta_campaign → create_meta_adset → create_meta_ad, with placements selectable per platform and position. Objects are created paused with no caller override, preview_meta_ad shows the real rendered ad per placement before you spend, and meta_insights breaks results down by age, gender, placement and country — which is the input to the next creative, not just a total.

What Codex cannot do on its own

An agent with a budget is only useful if the blast radius is bounded, so the fence is in the server rather than in a prompt. Every ad campaign, ad set, ad group and ad is created paused, and the status switches that arm real money refuse to run without an explicit confirmation flag. Every render is quoted first — hermoso_capabilities publishes each model’s exact credit cost before anything spends — and credits are reserved before the first provider call and settled at the exact cost afterwards, so a failed dispatch refunds rather than leaving you billed for nothing. Deletes are confirm-gated too, and every campaign tree is read back from the ad platform before your agent tells you what it built.

One step is deliberately not headless: linking an account is an OAuth consent screen, so you connect the channel once in a browser. Everything after that is a tool call.

The rest of the matrix

From Codex, post to: Facebook · Threads · TikTok · YouTube · X · LinkedIn · Pinterest — or see everything Codex can publish to.

Post to Instagram from: Claude · ChatGPT · Claude Code · Cursor · Cline · OpenClaw · Hermes · Ads from the command line

Frequently asked questions

Can Codex post to Instagram?

Yes, through Hermoso's MCP server. Create an API key in Hermoso under Settings → Agents & API keys, then add https://app.hermoso.ai/mcp to Codex with an Authorization: Bearer header. Codex then has 301 tools, including the ones that publish to Instagram — and the ones that research the ads already running in your market and render the creative in the first place.

How do I connect Instagram to Codex?

Two steps, once each. Create an API key in Hermoso under Settings → Agents & API keys, then add https://app.hermoso.ai/mcp to Codex with an Authorization: Bearer header. Then connect Instagram inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that Codex publishes to Instagram as an ordinary tool call.

Can Codex post a carousel to Instagram?

Yes — 2 to 10 slides, and images and video can be mixed. Ten is Meta’s own published limit, not one Hermoso invented. Codex calls the same publish tool either way, and a channel that cannot carry a carousel is refused with the real reason attached.

What does it cost to post to Instagram from Codex?

Publishing to Instagram costs no credits; Meta charges nothing per API call. Credits go on the render itself. Plans are $19, $49 and $149 a month for 1,000, 3,000 and 10,000 credits, and every feature is on every plan including Free — the only exception is enterprise SSO.

Start free — 25 credits at signup and 250+ more to earn, and every feature on every plan.

Start free → See pricing