# Second Brain Backfill

> >-

- **Type:** Skill
- **Install:** `agentstack add skill-undefined-ui-second-brain-os-second-brain-backfill`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [undefined-ui](https://agentstack.voostack.com/s/undefined-ui)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [undefined-ui](https://github.com/undefined-ui)
- **Source:** https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-backfill
- **Website:** https://x.com/undefinedKi/status/2068306794116501544

## Install

```sh
agentstack add skill-undefined-ui-second-brain-os-second-brain-backfill
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Backfill an archive

A backfill is where cost and quality both go wrong quietly. Done in the wrong
order it also inverts the vault's history, because later sources should update
pages that earlier ones created.

## Core rule

Oldest first, ten sources per batch, stop for a go-ahead between batches.

## Workflow

1. **Triage before ingesting.** Read titles and first paragraphs. Sort into
   worth-ingesting, keep-in-raw, and delete. Most archives are half dead links
   and things saved but never opened.
2. **Order by date, oldest first.** Run it the other way and every old source
   arrives as a contradiction against a page that already has the final answer.
3. **Batch of ten.** Ingest following `second-brain-ingest`.
4. **Checkpoint:** update `index.md`, append to `log.md`, commit with the batch
   range in the message, report counts.
5. **Stop and wait** before the next batch.
6. **Full lint at the end.** Large imports always leave orphans and duplicates.

## Output format

```
Batch /: 
Ingested:  sources ->  new pages,  updated,  links
Skipped:  (reason)
Running total:  of 
Next batch: 
```

## Calibration

Read every page the first batch produced, all of them. A flaw you let through in
batch one is a flaw in four hundred pages by the end, and fixing it afterwards
costs more than the original run.

If the archive is over about two hundred sources, propose a filter before
starting rather than quoting the full cost.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [undefined-ui](https://github.com/undefined-ui)
- **Source:** [undefined-ui/second-brain-os](https://github.com/undefined-ui/second-brain-os)
- **License:** MIT
- **Homepage:** https://x.com/undefinedKi/status/2068306794116501544

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-undefined-ui-second-brain-os-second-brain-backfill
- Seller: https://agentstack.voostack.com/s/undefined-ui
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.