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 Threads, and what Threads 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 copiedmcpServersblock 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 Threads 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 Threads tools Codex gets
post_to_meta— publishes withtarget: "threads"— text, image or video, and optionally geotagged.schedule_post— queues it alongside every other channel.list_threads_posts / threads_insights— what you have posted, and how each one did.list_threads_replies / reply_to_thread / hide_thread_reply— read the replies, answer as the brand, hide what does not belong.list_threads_mentions— who is talking about you.search_threads_keyword / search_threads_locations— keyword search and the location ids a geotag needs.delete_thread— removes a post.
Threads is the channel where Hermoso goes furthest past publishing. Beyond posting there is a full read-and-respond surface — replies, mentions, keyword search and per-post insights — which is what makes it usable as a listening channel and not just an outlet. Note that Threads is a separate OAuth grant from Facebook even though it shares the Page.
Threads limits worth knowing before you automate anything
| Text | A Threads post is capped at 500 characters — the tightest here except X. 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 — “Threads has no unlisted, private or draft post.” A Threads post exists publicly or not at all. |
| Carousel | 2 to 20 slides, images and video mixed. Both bounds are Meta’s own words, quoted in the table that enforces them: “Carousels must have at least 2” items, and “no more than 20 total images, videos, or a mix of the two.” That makes Threads the most generous mixed-media carousel of any channel here. |
| Which account | pageId — the same connected Page identity carries Facebook, Instagram and Threads. |
Try it in Codex
Ask for it in ordinary language — these are sentences, not a DSL:
“Every weekday at 9am: read the new entries in the changelog, write one Threads post under 500 characters, post it, and log the id.”
That walks get_brand → generate_text → post_to_meta (target: "threads") → list_threads_replies. 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 Threads: the part that bites
Enforce the 500-character cap in the prompt as well as relying on the enqueue check — an unattended run that fails validation is a job that did not post, and on a daily cadence that is a silent gap. The listening half works the same way: list_threads_mentions returns structured results a cron-shaped run can act on.
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 Threads before you post
search_threads searches public Threads by keyword through the research surface, and search_threads_keyword does the same through your connected Threads account. There is no Threads ad library, because there are no Threads ads to archive.
The paid half
There is no Threads ads product in Hermoso, and it would be wrong to imply one. Threads here is an organic channel: publish, read, reply, measure. The paid tools cover Meta (Facebook and Instagram), Google Ads, Microsoft Advertising, Reddit Ads, LinkedIn, Pinterest and ChatGPT Ads.
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 · Instagram · TikTok · YouTube · X · LinkedIn · Pinterest — or see everything Codex can publish to.
Post to Threads from: Claude · ChatGPT · Claude Code · Cursor · Cline · OpenClaw · Hermes · Ads from the command line
Frequently asked questions
Can Codex post to Threads?
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 Threads — and the ones that research the ads already running in your market and render the creative in the first place.
How do I connect Threads 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 Threads inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that Codex publishes to Threads as an ordinary tool call.
Can Codex post privately or as a draft to Threads?
No. Threads has no unlisted, private or draft post; a Threads post is public or it does not exist. Hermoso refuses a visibility Threads cannot honour at the moment you ask for it, rather than quietly publishing something weaker.
Can Codex schedule a Threads post for later?
Yes. schedule_post queues it on one calendar shared with every other channel, with a per-channel caption if the copy should differ, and list_scheduled and cancel_scheduled read and pull it back. Threads is one of the eight channels that queue.
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