diff --git a/src/core/coin_params.hpp b/src/core/coin_params.hpp
new file mode 100644
index 000000000..0fe31d128
--- /dev/null
+++ b/src/core/coin_params.hpp
@@ -0,0 +1,133 @@
+#pragma once
+
+// CoinParams: the "net" equivalent from Python p2pool.
+// A single struct that carries ALL coin-specific and pool-specific parameters.
+// Flows through the entire stack — share verification, tracker, node, stratum.
+// Each coin module (ltc, dash, doge, btc) provides a factory function
+// that returns a populated CoinParams instance.
+
+#include "pow.hpp"
+#include "uint256.hpp"
+
+#include <array>
+#include <cstdint>
+#include <functional>
+#include <set>
+#include <string>
+#include <vector>
+
+namespace core
+{
+
+struct CoinParams
+{
+    // =======================================================================
+    // Coin-level parameters (p2pool's net.PARENT)
+    // =======================================================================
+
+    std::string symbol;                      // "LTC", "DASH", "BTC", "DOGE"
+    uint32_t block_period = 0;               // target block interval (seconds)
+
+    // Address encoding
+    uint8_t address_version = 0;             // P2PKH version byte
+    uint8_t address_p2sh_version = 0;        // P2SH version byte
+    uint8_t address_p2sh_version2 = 0;       // secondary P2SH version (LTC: 5)
+    std::string bech32_hrp;                  // bech32 prefix ("ltc1", "bc1", "")
+
+    // PoW
+    PowFunc pow_func;                        // scrypt, sha256d, x11, ...
+    BlockHashFunc block_hash_func;           // block identity hash (usually sha256d)
+
+    // Block rewards
+    SubsidyFunc subsidy_func;                // height -> reward in satoshis
+
+    // Dust
+    uint64_t dust_threshold = 0;
+
+    // Softforks
+    std::set<std::string> softforks_required;
+    uint32_t segwit_activation_version = 0;  // 0 = no segwit (Dash)
+
+    // =======================================================================
+    // Pool-level parameters (p2pool's net)
+    // =======================================================================
+
+    uint16_t p2p_port = 0;                   // p2pool P2P port
+    uint16_t worker_port = 0;                // Stratum port
+
+    uint32_t share_period = 0;               // target share interval (seconds)
+    uint32_t chain_length = 0;               // PPLNS window size (shares)
+    uint32_t real_chain_length = 0;          // actual chain length for lookups
+    uint32_t target_lookbehind = 0;          // shares to look back for target calc
+    uint32_t spread = 0;                     // PPLNS spread multiplier
+    uint32_t minimum_protocol_version = 0;   // min p2pool protocol version
+    uint32_t block_max_size = 0;
+    uint32_t block_max_weight = 0;
+
+    uint256 max_target;                      // easiest allowed share difficulty
+
+    // Network identification
+    std::string identifier_hex;              // 8-byte hex identifier
+    std::string prefix_hex;                  // 8-byte hex prefix
+    std::string testnet_identifier_hex;
+    std::string testnet_prefix_hex;
+
+    // Bootstrap peers
+    std::vector<std::string> bootstrap_addrs;
+
+    // Donation scripts (consensus-critical)
+    DonationScriptFunc donation_script_func;
+
+    // Share version
+    uint32_t current_share_version = 0;      // 36 (LTC), 16 (Dash)
+
+    // =======================================================================
+    // Stratum vardiff config (matches upstream ref per coin)
+    // =======================================================================
+    //
+    // LTC defaults match p2pool-merged-v36/bitcoin/stratum.py (jtoomim's
+    // two-trigger algorithm with N−1 interval denominator).
+    //
+    // Dash overrides match p2pool-dash/dash/stratum.py + networks/dash.py
+    // (ASIC-tuned three-trigger algorithm with quickup support and tighter
+    // clip bounds; uses N interval denominator).
+    struct VardiffConfig
+    {
+        double target_share_rate = 3.0;      // target seconds per pseudoshare
+        uint32_t shares_trigger  = 12;       // trigger 1: adjust after this many shares
+        double timeout_mult      = 10.0;     // trigger 2: adjust if time > mult * N * rate
+        // Quickup trigger (p2pool-dash only; set quickup_shares = 0 to disable):
+        uint32_t quickup_shares  = 0;        // trigger 3: need at least N shares
+        double quickup_divisor   = 3.0;      // trigger 3: fire if time < target_time/divisor
+        double min_adjust        = 0.1;      // clip(ratio, min, max) bounds
+        double max_adjust        = 10.0;
+        // Denominator policy for actual_rate calculation:
+        //   false → N−1 intervals (matches p2pool-merged-v36 LTC: del [0])
+        //   true  → N shares      (matches p2pool-dash: no del)
+        bool use_full_window     = false;
+    };
+    VardiffConfig vardiff;
+
+    // Runtime state
+    bool is_testnet = false;
+
+    // =======================================================================
+    // Convenience accessors (testnet-aware, like PoolConfig:: methods)
+    // =======================================================================
+
+    // These are populated by the coin module's factory based on is_testnet.
+    // Unlike PoolConfig's static methods, these are already resolved at
+    // construction time — no branching needed at call sites.
+
+    const std::string& active_identifier_hex() const
+    {
+        return is_testnet ? testnet_identifier_hex : identifier_hex;
+    }
+
+    const std::string& active_prefix_hex() const
+    {
+        return is_testnet ? testnet_prefix_hex : prefix_hex;
+    }
+};
+
+} // namespace core