crumbs.fyi

Crumbs

Leave a crumb now. It finds you in Slack later.

Hard-won context, packaged while it’s fresh and delivered when it matters — to future you, a teammate, or an agent with no history.

Get started See a crumb

Context has a half-life

The expensive part of knowledge work is the understanding. And understanding dies fast: work goes to sleep waiting on a reply, gets parked for a sprint, or moves to someone else’s plate, and whoever picks it up pays the full cost of rebuilding it.

A crumb saves the understanding while it still exists — and hands it to whoever needs it next.

Hand off a solved mystery

You spent the afternoon mapping a failure in a complex repo. Leave a crumb and a coworker’s agent starts from your map — root cause, ruled-out theories, exact files.

Think out loud now, digest later

Dictate your thoughts on a walk. The crumb packages them up and finds you when you’re back at a desk, ready for an agent to turn into real work.

Agents that brief their humans

Background agents can be trained to leave crumbs about what their human should know — each one skimmable by you, actionable by the next agent.

Both sides of a crumb

You build the understanding with an LLM once. Weeks later, an agent with no history gives it back.

CursorToday

I finally understand the checkout flakiness — the retry queue in billing-worker double-charges when Stripe webhooks arrive out of order. I can’t touch it during the payments freeze. Leave a crumb for when it lifts on the 24th.

Done — it’ll find you in Slack on Aug 24 at 9:00am.

CrumbsAPP

Fix: double-charge in billing-worker

Open in ChatGPT

Slack just taps you on the shoulder

ChatGPTAug 24

Picking up your crumb from Aug 1: retries re-enqueue Stripe webhook events without their idempotency key, so they double-charge. You already ruled out the SDK — the consumer is services/stripe/consumer.ts. Start on the fix?

Yes — draft it.

Slack isn’t the destination — it’s the alert. One tap opens the crumb in whichever client you like: ChatGPT, Claude, or Cursor.

Not another memory feature

Subtext, not fuzzy recall
Packaged at write time — names resolved to ids, shorthand spelled out, dead ends ruled out. Nothing is left for an embedding search to guess at later.
MCP, not a walled garden
Works in any client or harness that speaks MCP. Leave a crumb from Cursor, pick it up in Claude or ChatGPT, or hand it to a background agent.
Delivery, not recall
It finds you in Slack at the moment you chose — one skimmable sentence for you, a full document underneath for your agent.

How it works

1
Connect
Add one URL to your MCP client and sign in with Slack.
2
Leave a crumb
Mid-conversation, in plain language: “if we haven’t heard back in three weeks, remind me to chase it.”
3
It finds you
A Slack DM at the time you chose, with one tap back into ChatGPT, Claude, or Cursor.

Get started

Pick your client and add Crumbs:

Add to Cursor

Opens Cursor and adds the Crumbs server to your MCP settings.

On first connect you’ll sign in with Slack and add the Crumbs bot to your workspace. Then ask your assistant to leave a crumb.