FIP-104 DRAFT : Miner-Only Index Mining Top-Ups via Allowlisted Mining Pools .

  FIP: 104
  Title: Miner-Only Top-Ups for Index Mining via Allowlisted Pools
  Author: TheLonelyBit, MrShiddy, Fractal Community Contributors
  Status: Draft
  Type: Standard Proposal (Staking Policy & Implementation)
  Created: 2026-07-17
  Updated: 2026-07-18
  Requires: FIP-101
  Layer: Staking System (non-consensus)
  Activation: N/A (non-consensus)
  Deployment: Staking portal, pool allowlist, documentation, and client update

Review Note (for core / Lorenzo)

1. 50 FB init for everyone (first Binding per indexer).
2. Sub-50 Top-Up only for ActiveMiner — allowlisted pool attestation; non-miners stay ≥ 50 FB.
3. No consensus / node change.
4. Owners: portal/tx-builder, staking docs, Fractal core (allowlist).
5. Stake address: UniSat connect or pubkey derive; optional pool pay-to-stake for attested miners.

Open for core: MIN_TOPUP (recommend 1 FB); MINER_ACTIVITY_WINDOW (default 7 days).

Abstract

This proposal refines FIP-101 Index Mining staking so official Top-Ups below 50 FB are available only to active miners, proven by Fractal-allowlisted mining pools.

50 FB remains the Initial Stake minimum for all users. After a Binding exists, sub-50 Top-Ups require Initialized ∧ ActiveMiner. Non-miner stakers keep ≥ 50 FB funding rules. Stake weight remains stake-address balance (FIP-101 unchanged). Stake address discovery uses UniSat (or equivalent) wallet connect and/or an open pubkey derive tool.

No changes to consensus Indexer blocks, scripts, proofs, 1:1:1 rewards, or settlement.

Proposal Summary

• Init: MIN_STAKE_INIT = 50 FB for first Binding (all users).
• Top-Up: amount ≥ MIN_TOPUP and < 50 FB only if ActiveMiner.
• Proof of miner: allowlisted pool attestation (not self-declare).
• Mechanics: Top-Up = pay bound stake address; no new consensus ops.
• Deploy: portal + allowlist + docs; no hard fork.

Motivation

FIP-101 set Merged Mining, Permissionless Mining, and Index Mining as co-equal pillars (1:1:1). Today those pillars are economically weakly linked for small miners: hashrate earns FB, but recycling that FB into Index Mining stake is blocked by a repeated 50 FB gate—even after a position is already open. This proposal does not merge block types or consensus tracks; it tightens the feedback loop between hashrate and indexing stake.

1. Compounding for real hashrate. Home and permissionless miners often earn ≪ 50 FB/day. After Initial Stake they need a path to Top-Up Index Mining with those smaller amounts. Without it, mining rewards sit idle or leave the indexing layer.

1. Privilege tied to verified work. Extending sub-50 Top-Ups to all stakers would weaken the 50 FB anti-dust gate. Miner-only access, proven by allowlisted pool activity (shares/payouts), matches FIP-101’s pattern: rewards follow real participation (proofs / hashrate), not self-declaration. Non-miners keep today’s ≥ 50 FB funding posture.

1. Ecosystem incentives across roles. When active miners can compound into Index Mining:
   • Miners earn from hashrate and can grow Index Mining yield on the same capital loop.
   • Indexer operators attract stickier, hashrate-linked stake and broader participation under their nodes.
   • The network deepens alignment between security/openness (merged + permissionless mining) and data availability (indexing)—growing TVL and habit in Index Mining without changing emission or 1:1:1.

1. Natural attestation layer. Allowlisted pools already observe shares and payouts; they can attest ActiveMiner status for portal admission without new consensus rules.

Goals & Non-Goals

Goals: miner-only sub-50 Top-Ups; keep 50 FB init; allowlist attestation; UniSat/pubkey stake-address discovery; no consensus risk.

Non-goals: Top-Ups for all stakers; self-declare as miner proof; lower cold-start below 50 FB; consensus/script/settlement changes; silent Stratum = stake address default.

Specification

1. Definitions

FIP-101 weight (unchanged): stake_weight = confirmed_balance(stake_address).

Official sub-50 Top-Up UX is gated by ActiveMiner. On-chain credits still affect balance; this FIP constrains portal policy (same layer as today’s 50 FB gate).

2. Admission

TopUpAllowed = Initialized(payout, indexer_id) AND ActiveMiner(payout)

1. Not Initialized → Stake builders must reject amount < MIN_STAKE_INIT. Initial Stake does not require ActiveMiner.
2. Official Top-Up with amount < MIN_STAKE_INIT must require TopUpAllowed and amount ≥ MIN_TOPUP; pay bound stake address (no new stake inscription required).
3. Initialized but not ActiveMiner → must not offer sub-50 Top-Up; require ≥ MIN_STAKE_INIT for official adds.
4. Unknown Binding or attestation → fail closed (no sub-50 Top-Up / enforce init minimum).

3. Stake-address discovery

stake_address = DeriveStakeAddress(indexer_id, user_pubkey, address_type)

Same as stake-indexer / unstake-tool (NUMS internal key + leaf with indexer_id / address_type / x-only pubkey).

Official portal must: UniSat connect (Fractal mainnet) → read address + pubkey → select indexer → derive and show stake address before Stake/Top-Up (client derive or POST /tx/stake-address).

Official or Fractal-sponsored tooling must also provide a keyless derive page/script (pubkey + indexer_id). Never request seeds/private keys.

Default pool config: Stratum reward = payout address. Optional auto-compound: after Initialized ∧ ActiveMiner, miner may set pool reward to stake address (P2TR); not silent default; control wallet remains Stake/Claim/Unstake actor.

Forbidden: self-declare as sole miner proof; derive stake address from payout alone; treat non-allowlisted “on a pool” as ActiveMiner.

4. Pool allowlist and attestation

1. Fractal core must publish a Pool Allowlist (pool_id, attestation URL, status); may add/suspend/remove pools.
2. Active if, within MINER_ACTIVITY_WINDOW, the address has accepted shares or a pool payout at that pool.
3. Pools should expose e.g. GET /v1/fip104/miner-attestation?address=... returning { pool_id, address, active, expires_at, ... } over HTTPS (optional signatures later).
4. Portal must query allowlisted endpoints; ActiveMiner if any returns active: true with future expires_at; cache ≤ 1 hour; errors → fail closed.
5. Attestation is portal policy, not consensus. Pools never hold stake keys. False attestations → delist. PrimeTriad (pool.primetriad.com) is an example eligible operator when listed—not exclusive.

Allowlisted pools may deep-link Top-Up or offer opt-in pay-to-stake; not required for activation.

5. Unchanged FIP-101 surfaces

Rewards, proofs, commission, settlement (~20,160 blocks), claim, scripts, 1:1:1: unchanged.

Security & Backward Compatibility

• 50 FB init preserved; non-miners cannot use official sub-50 Top-Up.
• Fake miners blocked by allowlist + activity window + fail-closed + delist.
• Wrong stake address mitigated by wallet-connect / Binding-only display.
• Existing Bindings valid; nodes need no upgrade; activates with portal + ≥1 allowlisted attestation path.

Execution Process

1. Core review; freeze MIN_TOPUP and MINER_ACTIVITY_WINDOW.
2. Publish allowlist + attestation schema.
3. Portal: derive, init, ActiveMiner-gated Top-Up.
4. Onboard pools; update docs; run test vectors; ship as staking-system release (no flag day).

Test Vectors

References

1. https://github.com/fractal-bitcoin/fips/blob/main/fip-101.md
2. https://github.com/fractal-bitcoin/stake-indexer
3. https://github.com/fractal-bitcoin/unstake-tool
4. https://docs.fractalbitcoin.io/overview/fip-101-fractal-standard-indexing-service/fip-101-guide-for-staking-users