Post to Bluesky from Codex

Hermoso is a marketing MCP server: 912+ 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 covers one slice of that: what Codex can actually do on Bluesky, and what Bluesky will not let it do.

Connect Hermoso to Codex

1. One command, and no key.

   codex plugin marketplace add hermoso-ai/hermoso && codex plugin add hermoso@hermoso

   Codex reads the marketplace file in Hermoso’s public repository and installs its five skills (research, ad-from-brand, generate, product-photoshoot and marketing). The skills run the hermoso command through npx, so no tool list is loaded into your sessions and nothing costs context until a command runs.
2. Sign in once.

   npx -y hermoso auth login

   It opens a browser sign-in and stores an owner-only credential in ~/.hermoso/config.json. No browser on that machine, say CI or a container? Create a key under MCP & CLI → Terminal & API keys and run npx -y hermoso auth login --token hmk_…. A key carries real spend authority, so treat it like a password.
3. Optional: the MCP server as well.

   codex mcp add hermoso -- npx -y hermoso mcp

   That writes the server into ~/.codex/config.toml and reads the same stored credential, so no key goes in the file. Prefer the hosted endpoint? codex mcp add hermoso --url https://app.hermoso.ai/mcp, then codex mcp login hermoso for the OAuth sign-in. The skills reach every tool without either.
4. 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.

Codex keeps MCP servers in ~/.codex/config.toml, or .codex/config.toml in a trusted project, and that file is TOML, not JSON: a copied mcpServers block will not load, and a hand-written entry is [mcp_servers.hermoso] with command = "npx" and args = ["-y", "hermoso", "mcp"]. The trailing mcp is load-bearing: npx -y hermoso with no subcommand prints help and exits. Codex reads plugin marketplaces in the same .claude-plugin layout Claude Code uses, which is why one repository installs in both.

Then connect Bluesky itself, once, under Settings → Connectors in Hermoso, with your handle and a Bluesky app password. There is no consent screen: the app password is made in Bluesky’s own settings, and it can be revoked there without touching your real password.

The Bluesky tools Codex gets

• post_to_bluesky: publishes a post as the connected account: up to 300 characters, with up to four images and alt text, or one MP4 video with optional caption tracks. A link with no media gets a preview card, which Hermoso builds because Bluesky does not fetch one.
• schedule_post: queues it on the calendar every other channel shares, with the 300-character cap checked when it is queued rather than when it fires.
• list_bluesky_posts: the account’s own recent posts with their AT-URIs and live counts, marking reposts so someone else’s post is never read as yours.
• bluesky_post_metrics / bluesky_account: likes, reposts, replies, quotes and bookmarks per post, and followers, following and post count for your account or any public one.
• list_bluesky_convos / read_bluesky_dm / send_bluesky_dm: read and answer direct messages, including message requests from people the account does not follow.
• manage_bluesky_convo / react_to_bluesky_dm / mark_bluesky_convo_read: accept a request, mute, lock or leave a conversation, react with one emoji, and clear unread counts.
• delete_bluesky_post: removes a post, after a first call that deletes nothing and reads back what would go.

Bluesky connects with an app password rather than a sign-in screen: create one in Bluesky’s settings and paste it with the handle under Settings → Connectors. Tick direct-message access when you create it, or the DM tools will tell you the password cannot chat, which is a property of the password and not a broken connection. Two more Bluesky rules Hermoso checks before sending: a video needs a confirmed email on the Bluesky account, and a link card and an image cannot share a post. Publishing costs no credits, because Bluesky charges nothing per call.

Bluesky limits worth knowing before you automate anything

Try it in Codex

Ask for it in ordinary language. These are plain sentences, not a DSL:

“Non-interactive: for each new tag, post one Bluesky update under 300 characters with a link card to the release page, and print the post URL as JSON.”

That walks get_brand → generate_image → post_to_bluesky → bluesky_post_metrics. 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 Bluesky: the part that bites

Video on Bluesky has a trap no retry fixes: Bluesky will not process a video from an account whose email is unconfirmed. Hermoso reports that as a refusal naming the cause rather than a failed upload, and reconnecting does not help, because it is a setting on the Bluesky account. Confirm the email once before you point a job at video. Text and image posts have no such gate.

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 Bluesky before you post

There is no Bluesky ad library and no Bluesky search in Hermoso, so competitor research there comes down to one honest thing: bluesky_account reads any public account’s followers, following and post count, which is enough to size a competitor and chart it week by week. Everything else in the research surface (the Meta, Google and LinkedIn ad libraries, organic TikTok, Instagram, YouTube, Reddit and Threads) is unaffected.

The paid half

There is no Bluesky ads product in Hermoso, and we do not imply one. Bluesky here is organic: publish, schedule, read, reply and measure. The paid tools cover Meta, Google Ads, Microsoft Advertising, Reddit Ads, LinkedIn, Pinterest, X Ads, TikTok Ads, Snapchat Ads, ChatGPT Ads, Apple Search Ads and AppLovin 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). 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 yours: creating the Bluesky app password and connecting it once. Everything after that is a tool call.

The rest of the matrix

From Codex, post to: Facebook · Instagram · Threads · TikTok · YouTube · X · LinkedIn · Pinterest · Telegram. Or see everything Codex can publish to.

Post to Bluesky from: Claude · ChatGPT · Claude Code · Cursor · Cline · OpenClaw · Grok Bot · Hermes · Gemini CLI · Perplexity · Le Chat · Claude Cowork · Perplexity Computer · Paperclip · Ads from the command line

Frequently asked questions

Can Codex post to Bluesky?

Yes, with Hermoso's Codex plugin. Run codex plugin marketplace add hermoso-ai/hermoso && codex plugin add hermoso@hermoso, which installs Hermoso's skills, then sign in once with npx -y hermoso auth login. The sign-in opens a browser and stores the credential itself, so there is no key to create and none to paste. For the MCP server as well, run codex mcp add hermoso -- npx -y hermoso mcp. Codex then has 912+ tools, including the ones that publish to Bluesky, plus the ones that research the ads already running in your market and render the creative in the first place.

How do I connect Bluesky to Codex?

Two steps, once each. Run codex plugin marketplace add hermoso-ai/hermoso && codex plugin add hermoso@hermoso, which installs Hermoso's skills, then sign in once with npx -y hermoso auth login. The sign-in opens a browser and stores the credential itself, so there is no key to create and none to paste. For the MCP server as well, run codex mcp add hermoso -- npx -y hermoso mcp. Then create an app password in Bluesky's settings (tick direct-message access if you want the DM tools) and paste it with your handle under Settings → Connectors in Hermoso. After that Codex publishes to Bluesky as an ordinary tool call.

What is the Bluesky caption limit when posting from Codex?

A Bluesky post is capped at 300 characters and at 3,000 bytes, so an emoji-heavy post can be under 300 characters and still be refused; Hermoso says which limit applied and by how much. Hermoso enforces it when the post is created or queued, so Codex is told immediately rather than failing later when nobody is watching.

Can Codex schedule a Bluesky 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. Bluesky is one of the eleven channels that queue.

Can Codex post privately or as a draft to Bluesky?

No. A Bluesky post is a public record on the AT Protocol, with no unlisted, private or draft form, so the review belongs before the call. Hermoso refuses a visibility Bluesky cannot honour at the moment you ask for it, rather than quietly publishing something weaker.

What does it cost to post to Bluesky from Codex?

Publishing to Bluesky costs no credits; Bluesky charges nothing per call. Credits are spent on generating the creative. 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.