Post to Tumblr from Codex

Codex drafts it. You approve it. PostDelegate posts it.Tumblr: Text, image or video posts on your blog.

How to post to Tumblr from Codex

Add PostDelegate to Codex. Add the server to ~/.codex/config.toml as below. Run codex mcp login postdelegate and sign in in your browser.
~/.codex/config.toml
```
[mcp_servers.postdelegate]
url = "https://app.postdelegate.com/mcp-oauth-dynamic"
```
Connect Tumblr in PostDelegate. On the calendar page choose Add Channel, then Tumblr. Sign in with Tumblr and approve the permissions PostDelegate asks for: posting to your blogs and staying signed in.
Ask Codex for a draft. Describe the post in plain words. Codex checks your Tumblr channel's rules, creates the post and sends back a preview link.

Teach Codex the posting rules

Add PostDelegate’s AGENTS.md to your repository, so Codex knows the MCP tools, the REST API and the safety rules when it works there. Agent files has the steps.

What to ask Codex

Mention any Tumblr setting in plain words and Codex fills it in. Codex can also read text files in your project, such as a changelog or a draft in Markdown.

Draft a Tumblr text post titled “Behind the scenes” about how we design our covers, with the tags design and process.
Schedule this image post from my media library on my Tumblr blog for Sunday at 12:00, and credit the source URL.
Turn posts/studio-tour.md into a Tumblr post with a title and tags, saved as a draft.

What Codex can do on your Tumblr channel

Check the rules first. Before writing, it reads your Tumblr channel's length limit (32,768 characters) and required settings.
Draft, schedule or post. It creates a draft, a scheduled post or an immediate post, and runs the same checks as the app.
Use your media. It attaches files from your media library or adds one from a public link.
Review and fix. It lists what is scheduled, changes the Tumblr settings of a post that has not gone out, and deletes posts you no longer want.

Tumblr is a blogging platform, and a PostDelegate post becomes one post on the blog you connected. It can hold long text, up to 30 images or a single MP4 video, with an optional title, a link, a source credit and tags.

Tumblr settings Codex can fill in

Setting	Notes
Title	Optional. Shown as a heading at the top of the post.
Link URL	Optional. Added to the post as a link.
Source URL	Optional. Credits where the content came from.
Tags	Optional. Separate tags with commas.

Before you start

Each post is published straight away on the blog, not saved as a draft on Tumblr. Keep a draft in PostDelegate to hold it back.
Tumblr caps how many posts, uploads and videos a blog can publish each day. A post over the cap fails with Tumblr's reason.

The Tumblr channel guide has every field, and MCP tools lists exactly what an assistant can and cannot do.

Questions

Will Codex publish to Tumblr without asking me?

Not unless you ask it to. Ask for a draft and the post waits on your calendar until you schedule it, and your workspace's approvals apply as usual. Tools that change data are marked as such, so Codex can ask you before it schedules or deletes anything.

Do I need an API key to connect Codex?

No. Codex signs in with your PostDelegate account through your browser. An API key is only for clients that cannot sign in, as described in MCP clients.

Does it cost extra to use Codex with PostDelegate?

No. The MCP server is on every plan, and Codex runs on your own Codex account, so PostDelegate never charges for AI. Every plan starts with a 7-day free trial with no card.

Can Codex attach images or video to a Tumblr post?

It can use files already in your media library, or add one from a public link. It cannot fetch files from your computer, so upload those in the app first. See MCP tools.

Can I schedule posts to more than one Tumblr blog?

Yes. Each connection is one blog. To post to another blog on the same Tumblr account, add it as a second channel from Add Channel.

What happens if I hit Tumblr's daily limit?

Tumblr caps how many posts, uploads and videos a blog can publish each day. A post that goes over the cap fails with Tumblr's reason shown on the calendar. Schedule it for the next day.

Tumblr from other assistants

Other networks from Codex

Prefer to plan Tumblr posts yourself? See the Tumblr scheduler.