Joao Silva United Kingdom 11H AGO

Everyone I know who runs a second brain uses Obsidian. The app is free, but sync is a subscription, and most AI integrations quietly assume you have it. I went another way: Joplin, which is free and open source, with an agent that reads my notebook through Joplin’s REST API, files my INBOX every morning while I sleep, and answers questions strictly from notes I actually wrote. It costs nothing beyond a VPS I already run, and the notebook still opens like a notebook. I use Hermes Agent on the VPS, Dropbox to sync notes between my devices, and Python scripts to connect the notebook and the agent. Every capture goes through `joplin_capture.py` and lands in a single INBOX folder with a source and timestamp attached. Captures can come from a Discord link, a thought from my phone, or a page from the web clipper. The process takes under ten seconds and requires no filing decisions at capture time, because filing at capture time is where second brains die. Joplin already ships with a REST API. I enable it with one setting and one token; the notebook then exposes HTTP on localhost:41184 with token authentication on every call. The same server powers the official web clipper, so this enables infrastructure I use anyway. There is no plugin, cloud service, or subscription. `joplin_filer.py` runs daily at 07:00 and uses a deterministic classifier to score each INBOX note against my existing folders. It uses token coverage rather than Jaccard, which dilutes single-token folders. Confident matches above 0.5 are moved into place: a hosting page goes to the hosting folder, while a security note goes to the security folder. Low-confidence notes stay in INBOX with the `needs-review` tag. Every move is logged to a FILER LOG note in the `__SYSTEM` folder, making the process auditable. The filer never deletes anything. I ran it in dry-run mode for a week before letting it touch a single note, and I recommend doing the same. When I want to know what I have learned, `joplin_ask.py` searches the corpus, reads the top notes in full, and answers with the note titles attached. It answers strictly from retrieved content. If the top hits are irrelevant, I refine the query before concluding there is nothing. It never invents a source, which matters when you write about security for a living. After each working session, `joplin_agent_log.py` prepends a digest to an AGENT LOG note in `__SYSTEM`. The log is newest first, append only, and syncs to my devices like everything else. The agent’s memory records what we did, decided, and deferred in the same place as the notes. The whole build is on GitHub: github.com/ciberjohn/mysecondBrain. It includes five Python scripts and the `joplin-brain` skill, which is the operating manual in a format another agent can load and follow. Step-by-step: 1. I enabled Joplin’s built-in REST API with one setting and one token. It serves HTTP on localhost:41184 with token authentication on every call and also supports the official web clipper. 2. I pointed Hermes Agent on my existing VPS at the Joplin REST API. 3. I routed every capture through `joplin_capture.py` into a single INBOX folder, attaching the source and a timestamp. Captures can come from Discord, my phone, or the web clipper. 4. I configured `joplin_filer.py` to run daily at 07:00 and score INBOX notes against my existing folders using token coverage rather than Jaccard. 5. I moved matches with scores above 0.5 into their folders, while leaving low-confidence notes in INBOX with the `needs-review` tag. 6. I logged every move in a FILER LOG note in the `__SYSTEM` folder and ensured that the filer never deletes anything. 7. I ran the filer in dry-run mode for a week before allowing it to move a note. 8. I used `joplin_ask.py` to search the corpus, read the top notes in full, and answer questions with the source note titles attached. When results were irrelevant, I refined the query. 9. After each working session, I used `joplin_agent_log.py` to prepend a digest to the newest-first, append-only AGENT LOG note in `__SYSTEM`. 10. I used Dropbox to sync notes between my devices and the REST API to move notes between Joplin and the agent—two separate pipes carrying the same notes in different directions.