obsidian-second-brain turns an Obsidian vault into persistent, searchable memory for Claude Code and other command-line coding agents, storing knowledge as linked Markdown notes. It is for developers, founders, writers, and researchers who want agents to retain project context across sessions. Its catalogue entries provide commands, hooks, a plugin, a skill, and instructions for capturing, finding, and maintaining that memory.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/eugeniughelbur/obsidian-second-brainWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/commands/eugeniughelbur/obsidian-second-brain/x-read)<a href="https://agentmods.dev/commands/eugeniughelbur/obsidian-second-brain/x-read"><img src="https://agentmods.dev/badge/commands/eugeniughelbur/obsidian-second-brain/x-read.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00032 | $0.00862 |
| Opus 5 | $0.00016 | $0.00431 |
| Sonnet 5 | $0.00006 | $0.00172 |
| Haiku 4.5 | $0.00003 | $0.00086 |
Grade A, and why
x-read scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Use the obsidian-second-brain skill. Execute /x-read [url]:
-
Resolve the URL from the user's argument. If no URL was given, ask: "Which X post URL?" Accept any URL containing
x.com/ortwitter.com/. -
Run the script from the skill root (its absolute path was given at session start as Skill root; substitute it for
SKILL_ROOT):uv run --directory "SKILL_ROOT" -m scripts.research.x_read "<url>" -
The script prints a structured analysis (ORIGINAL POST, THREAD, TL;DR, KEY CLAIMS, REPLY SENTIMENT, NOTABLE COUNTER-ARGUMENTS, VOICES TO WATCH) and a one-line cost summary on stderr. Show the analysis to the user verbatim - don't paraphrase or summarize.
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Default save behavior: chat only. Do NOT save the analysis to the vault automatically. The user must ask explicitly ("save this", "save to vault", "/obsidian-save") for it to be archived.
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If the user asks to save: write an AI-first note to
Research/X-reads/YYYY-MM-DD - <slug>.mdin the vault, following the AI-first vault rule (Section 0 of_CLAUDE.md):- Frontmatter:
date,time,type: x-read,ai-first: true,post-url,post-author(if known),key-claims(list),tags,related-people(wikilinks for any @ handles that map to known people in the vault),cost-usd - Body starts with a
## For future agentpreamble section (2-3 sentences summarizing what this post is about and why it was saved) - Then the full structured analysis from the script
- Frontmatter:
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Plain English triggers that route to this command: "read this tweet", "read this X post", "what's in this tweet", "analyze this X link" - when followed by a URL.
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If the script fails with a clear error (missing key, network down), surface the error message verbatim. The script handles retry on transient errors automatically.
AI-first rule: Every note created or updated by this command MUST follow references/ai-first-rules.md - ## For future agent preamble, rich frontmatter (type, date, tags, ai-first: true, plus type-specific fields), recency markers per external claim, mandatory [[wikilinks]] for every person/project/concept referenced, sources preserved verbatim with URLs inline, and confidence levels where applicable. If that path does not resolve from your working directory, search upward for it; if you still cannot read it, say so before writing rather than producing a note that silently skips the rule. The vault is for future agent retrieval - not human reading.
Anti-fabrication: Search exhaustively before claiming any note, person, or file is absent - false absence is the most common failure mode - and never invent facts, entities, or dates (mark unknowns as TBD). See the anti-fabrication and search-completeness hard rules in references/ai-first-rules.md.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 37 lines · 32 tokens per session scan A 3cc6a1a9a0da
x-read is a command published in the GitHub repository eugeniughelbur/obsidian-second-brain (4,364 stars, last pushed yesterday), licensed MIT. It adds 32 tokens to every session and 862 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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