Stratum: how your miner talks to a pool
Stratum is the work-delivery protocol between your miner and the pool: the pool sends candidate blocks, your miner sends back proofs of work (shares). Getting the endpoint, port, and worker name right is day-one configuration.
The conversation
A lone miner cannot cover every nonce for a whole block, so pools farm the work out. Over Stratum, the pool sends your miner a job: a block candidate (minus the winning nonce). Your miner grinds nonces on it and reports solutions that clear a much lower bar — the share difficulty — back to the pool. The pool counts those shares to measure your contribution (see how pools work).
One connection carries it all: job updates when the block template changes (new transactions, a new previous block), share submissions, and occasional difficulty adjustments. When a submitted share also clears the network target, it is a full block and the pool claims the reward for everyone accounting.
Anatomy of a pool URL
| Piece | Example | What it is |
|---|---|---|
| Protocol | stratum+tcp:// | Transport — V1 plaintext TCP is still common; stratum+tls or V2 encrypted exists |
| Host | pool.example.com | The pool's endpoint — must match the COIN, not just the brand |
| Port | :3333 | Selects algorithm/protocol variant — wrong port = zero shares |
| User | wallet.worker1 | Payout address or account, plus a worker label you choose |
| Password | x | Legacy field — literally 'x' on most pools; never a real password |
First-day checklist
- Endpoint matches the coin's algorithm (a RandomX port will not pay you for scrypt work).
- Worker name format matches the pool's docs — it becomes your dashboard identity.
- Shares appear as *accepted* within minutes; *rejected/stale* over ~2% means latency trouble.
- Keep the payout address and any API keys separate from worker credentials.
Failover: serious setups list 2–3 pool URLs so the miner switches automatically when one hiccups — cheap insurance against a flat earnings day.
See it live on pow.family
Every project page lists its live pools with fees and payout schemes — the quick-start blocks paste the exact Stratum endpoints miners used on our test fleet.