second-brain

second-brain files the posts and pages you share into a private Markdown wiki. When something you save sparks a thought of your own, it can plant that thought in your garden as a latent embryo.

share a post ──► second-brain worker (GitHub Actions) ──► POST /api/integrations/embryos ──► LATENT embryo
                     files the capture in the wiki             Bearer hyp_…

The two projects move on their own; what the bridge needs is tracked in the Lab roadmap under the Loop — … cards.

What arrives

• The seed is your note, the text you typed when sharing — never the model's summary of the post. A capture shared without a note plants nothing.
• What sparked it stays beside the seed: sourceUrl (the original post), sourceRef (the source note in your wiki repository), sourceTitle and sourceContext, the capture's essence as the wiki describes it (summary, what it shows, key ideas, visual style; never the quoted post text). The embryo page shows it folded under the seed, with both links. The wiki link opens on GitHub, so only people with access to that private repository can read it.
• The agent reads the essence as context for what "this" refers to, clipped to 4,000 characters, with a rule to challenge what you want from it and never to describe it back or suggest copying it.
• The wiki's index also arrives after every capture and weekly lint pass: topic and item names with their model-written summaries, never the saved posts or source notes. hypar keeps only the latest one per user (Settings → saved references shows it and can clear it). The agent reads it only while probing (GERMINATING) or opening paths (GROWING), as contrast for your idea and never as a recommendation — see saved references as contrast. Clearing the snapshot in Settings turns that off until the next capture.
• The CREATED event is initiated by SYSTEM and records the token name as via.
• Delivery is idempotent on sourceUrl: a retried capture returns the embryo already planted, and fills in source fields it was missing (so sharing an old capture again adds its essence).

Connect it

1. In hypar, open Settings → integrations and create a token (the name defaults to second-brain). Copy it: only its SHA-256 hash is stored, so it can't be shown again.

2. In your wiki repository, add the secrets:

   gh secret set HYPAR_URL -R <owner>/second-brain-wiki     # e.g. https://hypar.example.com
   gh secret set HYPAR_TOKEN -R <owner>/second-brain-wiki   # the hyp_… token

3. Share a post with the Shortcut, choose Idea to grow and write the thought it gave you.

Revoke a token from the same settings panel; requests with it fail with 401 from then on.

API

POST /api/integrations/embryos with Authorization: Bearer hyp_…

{
  "seed": "…",
  "sourceUrl": "https://…",
  "sourceRef": "https://github.com/…/wiki/sources/…md",
  "sourceTitle": "Interactive Component Preview Hover",
  "sourceContext": "A grid of component cards…\n\n## What it shows\n…"
}

Returns 201 { created: true, embryo }, or 200 { created: false, embryo } when an embryo with that sourceUrl already exists. Only http(s) links are kept. Rate limited to 30 requests per minute per IP.

PUT /api/integrations/references with the same token

{ "markdown": "# Second brain\n…", "commit": "9975bf6…" }

Replaces the user's snapshot of wiki/index.md (up to 200,000 characters) and returns { updatedAt, commit, topics, chars }. Shares the rate limit above.

Sessions don't authenticate integration routes, and tokens don't authenticate the rest of the API.