How to Automate Social Media Operations with a "Second Brain" (Claude x Obsidian Guide with Prompts)

Connecting Claude and Obsidian to create a "Second Brain" is becoming a hot topic overseas.

Among famous overseas engineers, the trend has completely shifted toward "Stop making AI write code and start making it build a Second Brain."

However, most people just "build it and finish." They feel smarter and satisfied just by having it.

I use this to automate social media operations themselves. No coding required. Just folders and prompts.

There are 5 prompts in total used in this article. I will provide them in a copy-paste format, so you can just paste them when you're done reading.

But before that, I've created an open chat to teach "how to make 100 million from zero" in this amazing AI era where you can create anything 👇

https://xytgf.notion.site/38c4361b791b809f819dc93555b5f468?source=copy_link

I will teach you new ways to earn in the AI era, perfect for small business entrepreneurship.

■ First, what is a "Second Brain"? (Basic Introduction)

The mechanism is simple. There is a free note-taking app called Obsidian, and it has one key feature: "All notes are saved as simple text files in a folder on your own PC."

Unlike Notion or Evernote, the data isn't on a company's server; it's in your hands. Overseas, this is called "File over app" (files are more important than the app). Even if the app goes bust or you stop your subscription, your notes remain forever as normal files.

Now, here's the main point. Since it's just a "folder," you can let Claude Code (AI) read it directly. All your notes, saved articles, and ideas become readable by the AI. In other words, your notepad becomes an "AI workplace."

If you're using Claude Code, the setup takes 3 steps and 15 minutes. The only extra thing you need is Obsidian (free). No coding at all.

【Step 1】 Install Obsidian

Just download it from the official site (obsidian.md). It's free and available for both Mac and Windows. Actually, you can just tell Claude Code: "Download Obsidian and set up the integration."

【Step 2】 Create a Vault in Obsidian

When you launch Obsidian, it will say "Create new vault." Just give it a name and choose a location. A "vault" sounds complicated, but it's just a "folder to put your notes in."

Once created, throw in your materials:

• Work notes and ideas
• Content of articles you enjoyed
• Past writings and documents

The trick is not to try too hard at first. To borrow a golden rule from overseas: "Start with 10 sources, not 10,000." Just 10 things related to your content distribution is enough.

【Step 3】 Tell Claude Code about the Vault

Open Claude Code and tell it the location: "Work in the vault folder I just made." If you asked it to handle the integration in Step 1, it already knows, so this isn't even necessary. Then, just paste the prompts below.

■ Building the "Second Brain" for Social Media Operations in One Go

I built my vault as a "shared folder for a social media operations team" from the start.

vault (SNS Operations Shared Folder)

├── Knowledge/

├── Writing Rules (Tone, phrasing, NG list)

├── Post Templates (Patterns of high-performing structures)

└── Account Design (Who to reach with what)

├── Ideas/

├── Random thoughts and idea notes

└── Records of insights, learnings, and failures

├── Drafts/

└── Post drafts (Unposted/Posted)

└── Records/

└── AI Work Logs (explained later)

The division of labor is simple:

• Where humans throw things (Ideas)
• Wisdom organized by AI (Knowledge)
• Deliverables (Drafts)
• Handover (Records)

The first prompt creates this structure.

【Prompt 1: Constructing the SNS Second Brain】

1I want you to build this folder as my "Second Brain" for social media operations.
2
3■ Create 4 folders
4- "Ideas" -> Where I throw things. Random thoughts, insights, learnings, failure records. 1 note per file. Keep these notes in my original words; do not rewrite them without permission.
5- "Knowledge" -> Where you organize ideas and materials. Writing rules, post templates, account design. 1 file per theme, connecting related pages with [[links]].
6- "Drafts" -> Storage for post drafts. Manage each file with a label at the top (property name "status", values: Unposted/Posted).
7- "Records" -> Where you write a daily log of your work.
8
9■ First tasks
101. Read the files currently in the vault and sort them into these four folders.
112. Create a draft of "Writing Rules.md" in "Knowledge." Infer the characteristics of my tone from my past notes and list them as bullet points. I will correct them if they are wrong.
123. Place a "Table of Contents" note at the top of each folder. This should be a list of links to all files in that folder. Always update this when files increase.
134. Save these operation rules in "Rules.md" and read them every time before working.
14
15■ Rules to follow
16- If I give you a note or article saying "put this in," save it in Ideas and reflect it in Knowledge if necessary.
17- If I ask a question, don't give general internet advice; answer from the contents of this folder first. Tell me which note you based it on.
18- Do not rewrite "Knowledge" without my permission.
19- If I say "maintain" once a week, look at the whole thing and report/fix contradictions, old info, or isolated notes with no links.

Just by pasting this, the "Social Media Team Shared Folder" is complete, and Claude starts organizing automatically. The point is: "Humans make judgments. AI handles recording and organizing." Outsource all the "tedious work" like linking notes, classifying, and cleaning up duplicates to the AI.

Note-taking methods have been failing since the 1960s for one simple reason: "The person in charge of organizing was a human." We changed that person to an AI. That's why this one sticks.

Another subtle but important point is the "Table of Contents" in the prompt. Making the AI read the whole folder every time is slow and it gets lost. If you make it read the Table of Contents (link list) first, the AI can grasp the whole picture just by following links.

■ Ideas are "Recorded," not "Collected"

The hardest part of social media is the daily search for topics. I used to look at viral posts and think, "Can I write something like that?" Now, I create posts by dropping everything that comes out of my daily life into the idea book.

• Insights during work
• Things I failed at
• Things I explained to people
• Things that made me think "I didn't know that"

The moment it hits you, tell Claude: "Put this in the idea book: [Content]." With just that, the AI adds a date and drops it in as one file.

【Prompt 2: Idea Inventory】

1Please perform an inventory of the "Ideas" folder.
21. Add two labels (properties) to the top of all notes. Property names: "status" (values: Unused/Used) and "theme" (value: the theme in one Japanese word).
3*From the second time onwards, only for new notes.
42. Create an "Unused Ideas List" section in the Ideas Table of Contents and update it. Write how many unused items there are at the top.
53. Then, read the entire Ideas folder and tell me:
6- 3 notes that I wrote thinking they were obvious, but might be valuable to readers.
7- Proposals for combining multiple notes into a single post.
84. Finally, recommend "the one to write today" with a reason.

Now, just by opening the Table of Contents, you can see "how many usable ideas I have right now." People who say "I have nothing to post" usually just aren't recording. When you let the AI dig, ideas come out of "notes you forgot you even wrote."

■ Creating Posts

Once the idea is set, let it write. The key here is not to let it write immediately.

【Prompt 3: Post Creation】

1I want you to create an X post. Follow this exact order.
21. First, read all the Writing Rules and NG list in "Knowledge."
32. Next, read 5 high-performing and 5 low-performing posts from the "Posted" section of "Drafts" and summarize the reason for the difference in one line. (Skip if there are no posts yet; accuracy improves as they accumulate.)
43. Then, write 3 drafts based on [Idea File Name] from the Ideas folder.
5
6■ Conditions for the 3 drafts
7- Each should have a different hook (e.g., starting with empathy / starting with numbers / starting with a contrarian view).
8- Add a one-line note to each draft explaining which past post it referenced and its goal.
9- Do not add information I haven't written. Do not exaggerate.
10
11■ Self-check after writing
12- If I only read the first 2 lines, would I want to read more?
13- Are there any phrases that feel out of place compared to my past posts?
14Fix any issues before presenting them. Once finished, save to "Drafts" with status: Unposted, and change the source idea's status to Used.

If you let it write from scratch, you get "corporate robot text." The core of this prompt is fixing the "reading process" before writing. By reading your knowledge and past posts first, it comes out in "your voice."

One failure of mine: at first, I told it the writing rules in the chat. "Make it softer," "That phrasing is NG." The next day, it would forget and I'd have to correct it again. AI is born with zero memory every time. Make it a rule for the AI to write corrections into the "Knowledge" file the moment you point them out. Once written in a file, it never makes the same mistake again. Chats disappear. Files remain. This is the simplest truth of the Second Brain.

■ The System where Accumulation "Automatically Becomes a Project"

Up to this point, scattered notes accumulate in the idea book. In normal apps, that's the end. They are never read again. The Second Brain is different; once a month, you hold a "Planning Meeting" with the AI.

【Prompt 4: Monthly Planning Meeting】

1Please hold a "Planning Meeting" for the vault.
2
3■ First, organize
41. If there are more than 30 notes in the Ideas folder, group similar themes and create a summary page for each theme in "Knowledge" (e.g., "Collection of failures in X," "Procedures for Y"). Link back to the original notes from the summary page.
52. Update the Table of Contents for each folder.
6
7■ Then, propose projects from 3 angles
81. [Repetition] Find things I've written about more than twice. Things I write repeatedly = my core themes. Propose them as a series.
92. [Gaps] Find topics I mention often but haven't dug deep into. That's the next post to write.
103. [Change] Find places where what I'm saying has changed between old and new notes. "I used to think this, but now I think that" is a post in itself.
11Propose 2 projects for each, 6 in total. Always include links to the source notes.

This is exactly what an editorial meeting does. The point is finding things you can't notice yourself. "You wrote the same idea three times this year. You haven't noticed. Your note app knows."

• Repeated topics = Your core theme
• Mentioned but shallow topics = Your next piece
• Changed opinions = Your growth becomes a post

You don't "think up" ideas; you "detect" them from accumulation.

■ Finally: Division of Labor (Organization)

We divide this flow into roles.

【Prompt 5: Team Organization】

1Organize a social media team that uses this vault as a shared folder.
2
3■ 3 Roles
4- Recorder -> Organizes notes I throw in, keeps the Table of Contents and Unused Ideas list up to date.
5- Planner -> Inventories ideas and proposes "this topic with this angle today." Does not rewrite files.
6- Editor -> Reads Knowledge and past posts to create drafts. Writes only to the "Drafts" folder.
7
8■ Things to create
91. Definition files for each role (specifying role, folders they can read/write, and what they must not do).
102. A "Daily Log" that each role writes at the end of their work. Leave it in the "Records" folder with a date, and start the next session by reading the previous log.
11
12I want my job to be only the final judgment on the drafts. The decision to post and the posting button must absolutely remain with me.

The reason for not letting one AI do everything is the same as a human company: multitasking drops accuracy. And the "Daily Log" is subtly effective. Since AI starts with zero memory, it usually needs re-explaining, but by reading its own log, it can do "the continuation of last time."

■ So, every morning I only say one thing

Once the organization is done, my morning starts with this:

"Good morning. Read yesterday's log, inventory the ideas, and report back with 3 post drafts for today."

Then the Recorder -> Planner -> Editor move in sequence, and by the time I finish my coffee, 3 drafts are lined up in the folder. All I do is look at them and decide whether to post. It's like having a one-person management company inside a folder.

■ To be honest

• It won't be fully automated from day one. The first 1-2 weeks are for "accumulating knowledge and ideas." If the folder is thin, the AI is thin. Think of it as a nurturing game.
• Final judgment should remain with humans. Automating the post button leads to accidents. Keep the line: "AI for work, human for judgment."
• Building the Second Brain itself is free as long as you have Claude.

■ What is this all about?

A "Second Brain" isn't a tool to become smart; it's a system to share business memory with an AI team. Notes become assets, assets become posts, and posts become revenue. Once this pipeline is built, even if a new AI model comes out, the folder (business memory) can be reused as is. Models change, but memory accumulates. That's what I wanted to convey!

■ The Best AI Era for Entrepreneurship

Famous overseas entrepreneurs say: "This is the best time in human history to be on the 'creator' side. You can make anything. Don't waste this moment." This is a once-in-a-lifetime chance. Besides this Claude x Obsidian method, there are many other AI business goldmines and latest info you must know. I will continue to share this information. If you want to ride this wave, don't miss my future posts and open chat! People riding this wave are changing their lives drastically.