diff --git a/Cargo.toml b/Cargo.toml
index a78d69b5..22962a3c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,8 @@
 [workspace]
 resolver = "2"
 members = [
-    "contracts/error_codes",
-    "contracts/math",
-    "contracts/staking_rewards",
+    "contracts/*",
 ]
+
+[workspace.dependencies]
+soroban-sdk = "22.0.0"
diff --git a/contracts/auction_factory/Cargo.toml b/contracts/auction_factory/Cargo.toml
index fabfb540..6dc62617 100644
--- a/contracts/auction_factory/Cargo.toml
+++ b/contracts/auction_factory/Cargo.toml
@@ -8,11 +8,11 @@ publish = false
 crate-type = ["rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 emergency_guard = { path = "../emergency_guard", default-features = false }
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 emergency_guard = { path = "../emergency_guard", default-features = false }
 
 [features]
diff --git a/contracts/batch_transfer/Cargo.toml b/contracts/batch_transfer/Cargo.toml
index 416025da..50b99f7c 100644
--- a/contracts/batch_transfer/Cargo.toml
+++ b/contracts/batch_transfer/Cargo.toml
@@ -8,8 +8,8 @@ publish = false
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 token-contract = { package = "soroban-token-contract", path = "../token" }
diff --git a/contracts/cdp/Cargo.toml b/contracts/cdp/Cargo.toml
index 12f87b08..bd696de0 100644
--- a/contracts/cdp/Cargo.toml
+++ b/contracts/cdp/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/concentrated_amm/Cargo.toml b/contracts/concentrated_amm/Cargo.toml
index 846e3df9..3d0bbfb8 100644
--- a/contracts/concentrated_amm/Cargo.toml
+++ b/contracts/concentrated_amm/Cargo.toml
@@ -10,7 +10,7 @@ crate-type = ["cdylib", "rlib"]
 testutils = ["soroban-sdk/testutils"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/cpu_heavy/Cargo.toml b/contracts/cpu_heavy/Cargo.toml
index 5ddca619..8dc646c7 100644
--- a/contracts/cpu_heavy/Cargo.toml
+++ b/contracts/cpu_heavy/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
\ No newline at end of file
+soroban-sdk = { workspace = true, features = ["testutils"] }
\ No newline at end of file
diff --git a/contracts/cross_call/Cargo.toml b/contracts/cross_call/Cargo.toml
index 5a3f6206..2702824c 100644
--- a/contracts/cross_call/Cargo.toml
+++ b/contracts/cross_call/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/cross_chain_payload/Cargo.toml b/contracts/cross_chain_payload/Cargo.toml
index d0356009..ee889d69 100644
--- a/contracts/cross_chain_payload/Cargo.toml
+++ b/contracts/cross_chain_payload/Cargo.toml
@@ -8,5 +8,4 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = { version = "20.5.0", features = ["testutils"] }
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/cross_chain_verifier/Cargo.toml b/contracts/cross_chain_verifier/Cargo.toml
index d74d551b..13a64a3e 100644
--- a/contracts/cross_chain_verifier/Cargo.toml
+++ b/contracts/cross_chain_verifier/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/crucible-example-gasless/Cargo.toml b/contracts/crucible-example-gasless/Cargo.toml
index d0c53e45..d186802c 100644
--- a/contracts/crucible-example-gasless/Cargo.toml
+++ b/contracts/crucible-example-gasless/Cargo.toml
@@ -7,5 +7,5 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
diff --git a/contracts/did_registry/Cargo.toml b/contracts/did_registry/Cargo.toml
index b3e5ff67..f939e829 100644
--- a/contracts/did_registry/Cargo.toml
+++ b/contracts/did_registry/Cargo.toml
@@ -9,7 +9,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
\ No newline at end of file
+soroban-sdk = { workspace = true, features = ["testutils"] }
\ No newline at end of file
diff --git a/contracts/dutch_auction/Cargo.toml b/contracts/dutch_auction/Cargo.toml
index 5d6b1d1f..bf4208d0 100644
--- a/contracts/dutch_auction/Cargo.toml
+++ b/contracts/dutch_auction/Cargo.toml
@@ -8,10 +8,10 @@ publish = false
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 token-contract = { package = "soroban-token-contract", path = "../token" }
 
 [features]
diff --git a/contracts/emergency_guard/Cargo.toml b/contracts/emergency_guard/Cargo.toml
index 952dfdba..a3138c8c 100644
--- a/contracts/emergency_guard/Cargo.toml
+++ b/contracts/emergency_guard/Cargo.toml
@@ -7,10 +7,10 @@ edition = "2021"
 crate-type = ["rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 
 [features]
 default = ["contract"]
diff --git a/contracts/english_auction/Cargo.toml b/contracts/english_auction/Cargo.toml
index f181a63b..4815c94c 100644
--- a/contracts/english_auction/Cargo.toml
+++ b/contracts/english_auction/Cargo.toml
@@ -8,10 +8,10 @@ publish = false
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 token-contract = { package = "soroban-token-contract", path = "../token" }
 
 [features]
diff --git a/contracts/error_codes/Cargo.toml b/contracts/error_codes/Cargo.toml
index 4dcf2ee7..e9375dbc 100644
--- a/contracts/error_codes/Cargo.toml
+++ b/contracts/error_codes/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/factory/Cargo.toml b/contracts/factory/Cargo.toml
index 874c3587..6eaf353c 100644
--- a/contracts/factory/Cargo.toml
+++ b/contracts/factory/Cargo.toml
@@ -9,10 +9,10 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 emergency_guard = { path = "../emergency_guard", default-features = false }
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 emergency_guard = { path = "../emergency_guard" }
 
 # We need the pool contract code for integration tests
diff --git a/contracts/flash_loan_vault/Cargo.toml b/contracts/flash_loan_vault/Cargo.toml
index b955d0bc..c737227e 100644
--- a/contracts/flash_loan_vault/Cargo.toml
+++ b/contracts/flash_loan_vault/Cargo.toml
@@ -7,8 +7,8 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 emergency_guard = { path = "../emergency_guard" }
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/governance/Cargo.toml b/contracts/governance/Cargo.toml
index b4301af8..bd901003 100644
--- a/contracts/governance/Cargo.toml
+++ b/contracts/governance/Cargo.toml
@@ -9,8 +9,8 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 emergency_guard = { path = "../emergency_guard" }
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 emergency_guard = { path = "../emergency_guard" }
diff --git a/contracts/hello_soroban/Cargo.toml b/contracts/hello_soroban/Cargo.toml
index 199b38cc..01ef9c5b 100644
--- a/contracts/hello_soroban/Cargo.toml
+++ b/contracts/hello_soroban/Cargo.toml
@@ -7,9 +7,9 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 
 
diff --git a/contracts/hybrid_amm_lob/Cargo.toml b/contracts/hybrid_amm_lob/Cargo.toml
index cf2cdd6c..d00c45e9 100644
--- a/contracts/hybrid_amm_lob/Cargo.toml
+++ b/contracts/hybrid_amm_lob/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/liquidity_pool/Cargo.toml b/contracts/liquidity_pool/Cargo.toml
index 012ee926..fe50cbf4 100644
--- a/contracts/liquidity_pool/Cargo.toml
+++ b/contracts/liquidity_pool/Cargo.toml
@@ -7,10 +7,10 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 emergency_guard = { path = "../emergency_guard", default-features = false }
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 emergency_guard = { path = "../emergency_guard" }
 proptest = "1.0"
diff --git a/contracts/math/Cargo.toml b/contracts/math/Cargo.toml
index ddfa3876..9acf8d71 100644
--- a/contracts/math/Cargo.toml
+++ b/contracts/math/Cargo.toml
@@ -7,8 +7,8 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 soroscope-error-codes = { path = "../error_codes" }
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/multi_yield_vault/Cargo.toml b/contracts/multi_yield_vault/Cargo.toml
index 6b41d2e7..84c0dbde 100644
--- a/contracts/multi_yield_vault/Cargo.toml
+++ b/contracts/multi_yield_vault/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/oracle_aggregator/Cargo.toml b/contracts/oracle_aggregator/Cargo.toml
index 48425915..662e2b8f 100644
--- a/contracts/oracle_aggregator/Cargo.toml
+++ b/contracts/oracle_aggregator/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/private_transfer/Cargo.toml b/contracts/private_transfer/Cargo.toml
index 632c00d9..5e39c98a 100644
--- a/contracts/private_transfer/Cargo.toml
+++ b/contracts/private_transfer/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/proxy/Cargo.toml b/contracts/proxy/Cargo.toml
index ae645b91..55a946ce 100644
--- a/contracts/proxy/Cargo.toml
+++ b/contracts/proxy/Cargo.toml
@@ -4,4 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/soulbound_token/Cargo.toml b/contracts/soulbound_token/Cargo.toml
index 9f762521..0424e4b7 100644
--- a/contracts/soulbound_token/Cargo.toml
+++ b/contracts/soulbound_token/Cargo.toml
@@ -9,7 +9,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
\ No newline at end of file
+soroban-sdk = { workspace = true, features = ["testutils"] }
\ No newline at end of file
diff --git a/contracts/staking_rewards/Cargo.toml b/contracts/staking_rewards/Cargo.toml
index c834259a..8401fa1f 100644
--- a/contracts/staking_rewards/Cargo.toml
+++ b/contracts/staking_rewards/Cargo.toml
@@ -8,10 +8,10 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 soroscope-math = { path = "../math" }
 soroscope-error-codes = { path = "../error_codes" }
 emergency_guard = { path = "../emergency_guard" }
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
\ No newline at end of file
+soroban-sdk = { workspace = true, features = ["testutils"] }
\ No newline at end of file
diff --git a/contracts/storage_heavy/Cargo.toml b/contracts/storage_heavy/Cargo.toml
index 8b416e91..4aeeeaee 100644
--- a/contracts/storage_heavy/Cargo.toml
+++ b/contracts/storage_heavy/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/timelocked_escrow/Cargo.toml b/contracts/timelocked_escrow/Cargo.toml
index 7f5442f8..e6442f08 100644
--- a/contracts/timelocked_escrow/Cargo.toml
+++ b/contracts/timelocked_escrow/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/token/Cargo.toml b/contracts/token/Cargo.toml
index edb0927f..f531eeae 100644
--- a/contracts/token/Cargo.toml
+++ b/contracts/token/Cargo.toml
@@ -10,8 +10,8 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 emergency_guard = { path = "../emergency_guard", default-features = false }
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
 emergency_guard = { path = "../emergency_guard", default-features = false, features = ["contract"] }
diff --git a/contracts/twap_oracle/Cargo.toml b/contracts/twap_oracle/Cargo.toml
index 9955edd9..f1cd7602 100644
--- a/contracts/twap_oracle/Cargo.toml
+++ b/contracts/twap_oracle/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
\ No newline at end of file
+soroban-sdk = { workspace = true, features = ["testutils"] }
\ No newline at end of file
diff --git a/contracts/typed_data_auth/Cargo.toml b/contracts/typed_data_auth/Cargo.toml
index 53180541..89d90ad8 100644
--- a/contracts/typed_data_auth/Cargo.toml
+++ b/contracts/typed_data_auth/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-soroban-sdk = "22.0.0"
+soroban-sdk.workspace = true
 
 [dev-dependencies]
-soroban-sdk = { version = "22.0.0", features = ["testutils"] }
+soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/web/components/FeeEstimationPreview.test.cjs b/web/components/FeeEstimationPreview.test.cjs
new file mode 100644
index 00000000..cdc86618
--- /dev/null
+++ b/web/components/FeeEstimationPreview.test.cjs
@@ -0,0 +1,264 @@
+// FeeEstimationPreview.test.cjs — unit tests for FeeEstimationPreview state and bump selection logic
+// Closes Issue #595
+// Runs with: node --test ./components/FeeEstimationPreview.test.cjs
+
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+// ── Inline fee estimation logic (mirrors src/lib/stellarRpc.ts) ──────────────
+
+const FeeBumpLevel = Object.freeze({
+  LOW: 'low',
+  MEDIUM: 'medium',
+  HIGH: 'high',
+});
+
+const BUMP_CONFIG = Object.freeze({
+  [FeeBumpLevel.LOW]: {
+    label: 'Low (Min)',
+    multiplier: 1.0,
+    description: 'Minimum fee, slower confirmation',
+  },
+  [FeeBumpLevel.MEDIUM]: {
+    label: 'Medium',
+    multiplier: 1.5,
+    description: 'Balanced speed and cost',
+  },
+  [FeeBumpLevel.HIGH]: {
+    label: 'High',
+    multiplier: 2.0,
+    description: 'Priority processing',
+  },
+});
+
+function stroopsToXlm(stroops) {
+  const xlm = stroops / 10_000_000;
+  if (xlm === 0) return '0';
+  if (xlm < 0.000001) return xlm.toFixed(9);
+  if (xlm < 0.001) return xlm.toFixed(7);
+  return xlm.toFixed(5);
+}
+
+function estimateFees(resourceCostStroops, feeStats) {
+  const baseClassicFee = (feeStats && feeStats.min_ledger_fee) || 100;
+  const surge = (feeStats && feeStats.surge_multiplier) || 1;
+  const sorobanRate = (feeStats && feeStats.soroban_fee_rate) || 1;
+
+  const minResourceFeeStroops = resourceCostStroops;
+  const classicFeeStroops = baseClassicFee;
+  const baseTotal = minResourceFeeStroops + classicFeeStroops;
+
+  const feeBumps = Object.values(BUMP_CONFIG).map((cfg) => {
+    const feeStroops = Math.ceil(baseTotal * cfg.multiplier * sorobanRate);
+    return {
+      label: cfg.label,
+      multiplier: cfg.multiplier,
+      feeStroops,
+      feeXlm: stroopsToXlm(feeStroops),
+      description: cfg.description,
+    };
+  });
+
+  return {
+    minResourceFeeStroops,
+    classicFeeStroops,
+    totalFeeStroops: baseTotal,
+    totalFeeXlm: stroopsToXlm(baseTotal),
+    feeBumps,
+    networkFees: {
+      low: feeBumps[0].feeStroops,
+      medium: feeBumps[1].feeStroops,
+      high: feeBumps[2].feeStroops,
+    },
+    surgeMultiplier: surge,
+  };
+}
+
+// ── FeeEstimationPreview state machine ────────────────────────────────────────
+
+function createFeeEstimationState(options = {}) {
+  const {
+    costStroops = 500_000,
+    rpcAvailable = true,
+  } = options;
+
+  let feeEstimate = null;
+  let selectedBump = 'Low (Min)';
+  let fetching = false;
+  let isRpcAvailable = rpcAvailable;
+  let lastCallbackArgs = null;
+
+  function loadFeeEstimate(stats) {
+    if (costStroops <= 0) {
+      feeEstimate = null;
+      return;
+    }
+    fetching = true;
+    // Simulate real component: if stats is null/undefined,
+    // RPC fetch failed (fetchFeeStats returned null or threw).
+    if (stats) {
+      feeEstimate = estimateFees(costStroops, stats);
+      isRpcAvailable = true;
+    } else {
+      feeEstimate = estimateFees(costStroops, null);
+      isRpcAvailable = false;
+    }
+    fetching = false;
+  }
+
+  function handleBumpSelect(bump, callback) {
+    selectedBump = bump.label;
+    if (callback) {
+      const level = bump.label.toLowerCase().includes('low') ? 'low'
+        : bump.label.toLowerCase().includes('high') ? 'high'
+        : 'medium';
+      lastCallbackArgs = { level, feeStroops: bump.feeStroops };
+      callback(level, bump.feeStroops);
+    }
+  }
+
+  function refresh() {
+    loadFeeEstimate(isRpcAvailable ? { min_ledger_fee: 100, surge_multiplier: 1, soroban_fee_rate: 1 } : null);
+  }
+
+  return {
+    get feeEstimate() { return feeEstimate; },
+    get selectedBump() { return selectedBump; },
+    get isFetching() { return fetching; },
+    get isRpcAvailable() { return isRpcAvailable; },
+    get lastCallbackArgs() { return lastCallbackArgs; },
+    loadFeeEstimate,
+    handleBumpSelect,
+    refresh,
+    setRpcAvailable(v) { isRpcAvailable = v; },
+    setSelectedBump(v) { selectedBump = v; },
+  };
+}
+
+// ── Tests ─────────────────────────────────────────────────────────────────────
+
+test('FeeEstimationPreview: initial state is empty when no cost data', () => {
+  const state = createFeeEstimationState({ costStroops: 0 });
+  state.loadFeeEstimate(null);
+  assert.equal(state.feeEstimate, null);
+});
+
+test('FeeEstimationPreview: loads fee estimate from resource cost', () => {
+  const state = createFeeEstimationState({ costStroops: 500_000 });
+  const mockStats = { min_ledger_fee: 100, surge_multiplier: 1, soroban_fee_rate: 1 };
+  state.loadFeeEstimate(mockStats);
+
+  assert.ok(state.feeEstimate !== null);
+  assert.equal(state.feeEstimate.minResourceFeeStroops, 500_000);
+  assert.equal(state.feeEstimate.classicFeeStroops, 100);
+  assert.ok(state.feeEstimate.feeBumps.length === 3);
+});
+
+test('FeeEstimationPreview: shows three fee bump options', () => {
+  const state = createFeeEstimationState();
+  state.loadFeeEstimate(null);
+
+  const bumps = state.feeEstimate.feeBumps;
+  assert.equal(bumps.length, 3);
+
+  assert.equal(bumps[0].label, 'Low (Min)');
+  assert.equal(bumps[1].label, 'Medium');
+  assert.equal(bumps[2].label, 'High');
+});
+
+test('FeeEstimationPreview: selecting a fee bump updates selected state', () => {
+  const state = createFeeEstimationState();
+  state.loadFeeEstimate(null);
+
+  const bumps = state.feeEstimate.feeBumps;
+  state.handleBumpSelect(bumps[1]);
+
+  assert.equal(state.selectedBump, 'Medium');
+});
+
+test('FeeEstimationPreview: fee bump selection fires callback with correct level', () => {
+  const state = createFeeEstimationState();
+  state.loadFeeEstimate(null);
+
+  const bumps = state.feeEstimate.feeBumps;
+  let callbackResult = null;
+
+  state.handleBumpSelect(bumps[2], (level, feeStroops) => {
+    callbackResult = { level, feeStroops };
+  });
+
+  assert.equal(callbackResult.level, 'high');
+  assert.ok(callbackResult.feeStroops > 0);
+});
+
+test('FeeEstimationPreview: low bump has lowest fee, high has highest', () => {
+  const state = createFeeEstimationState();
+  state.loadFeeEstimate(null);
+
+  const fees = state.feeEstimate.networkFees;
+  assert.ok(fees.low < fees.medium, 'Low < Medium');
+  assert.ok(fees.medium < fees.high, 'Medium < High');
+});
+
+test('FeeEstimationPreview: rpc offline flag shown when stats fetch fails', () => {
+  const state = createFeeEstimationState({ rpcAvailable: false });
+  state.loadFeeEstimate(null);
+
+  assert.equal(state.isRpcAvailable, false);
+  assert.ok(state.feeEstimate !== null);
+});
+
+test('FeeEstimationPreview: refresh reloads fee estimate', () => {
+  const state = createFeeEstimationState({ costStroops: 100_000 });
+  state.loadFeeEstimate(null);
+
+  const beforeFee = state.feeEstimate.totalFeeStroops;
+
+  state.setRpcAvailable(true);
+  state.refresh();
+
+  assert.ok(state.feeEstimate !== null);
+  assert.equal(state.feeEstimate.totalFeeStroops, beforeFee);
+});
+
+test('FeeEstimationPreview: returns correct fee breakdown for a known resource cost', () => {
+  const state = createFeeEstimationState({ costStroops: 1_234_567 });
+  state.loadFeeEstimate({ min_ledger_fee: 100, surge_multiplier: 1, soroban_fee_rate: 1 });
+
+  const est = state.feeEstimate;
+  assert.equal(est.minResourceFeeStroops, 1_234_567);
+  assert.equal(est.classicFeeStroops, 100);
+  assert.equal(est.totalFeeStroops, 1_234_667);
+  assert.equal(est.surgeMultiplier, 1);
+});
+
+test('FeeEstimationPreview: surge multiplier > 1 increases all fee bump levels', () => {
+  const baseCost = 500_000;
+  const normal = estimateFees(baseCost, { min_ledger_fee: 100, surge_multiplier: 1, soroban_fee_rate: 1 });
+  const surged = estimateFees(baseCost, { min_ledger_fee: 100, surge_multiplier: 3, soroban_fee_rate: 2 });
+
+  assert.ok(surged.surgeMultiplier > normal.surgeMultiplier);
+  assert.ok(surged.networkFees.low > normal.networkFees.low);
+  assert.ok(surged.networkFees.medium > normal.networkFees.medium);
+  assert.ok(surged.networkFees.high > normal.networkFees.high);
+});
+
+test('FeeEstimationPreview: handles very small resource costs', () => {
+  const state = createFeeEstimationState({ costStroops: 1 });
+  state.loadFeeEstimate(null);
+
+  assert.ok(state.feeEstimate !== null);
+  assert.equal(state.feeEstimate.minResourceFeeStroops, 1);
+  assert.ok(state.feeEstimate.totalFeeStroops > 1);
+});
+
+test('FeeEstimationPreview: handles very large resource costs without overflow', () => {
+  const state = createFeeEstimationState({ costStroops: 1_000_000_000_000 });
+  state.loadFeeEstimate(null);
+
+  assert.ok(state.feeEstimate !== null);
+  assert.ok(state.feeEstimate.totalFeeStroops > 1_000_000_000_000);
+  assert.ok(Number.isFinite(state.feeEstimate.totalFeeStroops));
+});
diff --git a/web/components/FeeEstimationPreview.tsx b/web/components/FeeEstimationPreview.tsx
new file mode 100644
index 00000000..adedcac8
--- /dev/null
+++ b/web/components/FeeEstimationPreview.tsx
@@ -0,0 +1,189 @@
+'use client';
+
+import React, { useState, useEffect, useCallback } from 'react';
+import { Fuel, Zap, TrendingUp, Gauge, DollarSign } from 'lucide-react';
+import type { FeeEstimate, FeeBumpOption } from '../lib/sorobantypes';
+import { useNetwork } from '../context/NetworkContext';
+import { fetchFeeStats, estimateFees, stroopsToXlm } from '../lib/stellarRpc';
+
+interface FeeEstimationPreviewProps {
+  costStroops?: number;
+  loading?: boolean;
+  onFeeBumpChange?: (level: string, feeStroops: number) => void;
+}
+
+export function FeeEstimationPreview({
+  costStroops = 0,
+  loading = false,
+  onFeeBumpChange,
+}: FeeEstimationPreviewProps) {
+  const { network } = useNetwork();
+  const [feeEstimate, setFeeEstimate] = useState<FeeEstimate | null>(null);
+  const [selectedBump, setSelectedBump] = useState<string>('low');
+  const [fetching, setFetching] = useState(false);
+  const [rpcAvailable, setRpcAvailable] = useState(true);
+
+  const loadFeeEstimate = useCallback(async () => {
+    if (costStroops <= 0) {
+      setFeeEstimate(null);
+      return;
+    }
+    setFetching(true);
+    try {
+      const stats = await fetchFeeStats(network.rpcUrl);
+      setRpcAvailable(true);
+      const estimate = estimateFees(costStroops, stats);
+      setFeeEstimate(estimate);
+    } catch {
+      const estimate = estimateFees(costStroops, null);
+      setFeeEstimate(estimate);
+      setRpcAvailable(false);
+    } finally {
+      setFetching(false);
+    }
+  }, [costStroops, network.rpcUrl]);
+
+  useEffect(() => {
+    loadFeeEstimate();
+  }, [loadFeeEstimate]);
+
+  const handleBumpSelect = (bump: FeeBumpOption) => {
+    setSelectedBump(bump.label);
+    if (onFeeBumpChange) {
+      const level = bump.label.toLowerCase().includes('low') ? 'low'
+        : bump.label.toLowerCase().includes('high') ? 'high'
+        : 'medium';
+      onFeeBumpChange(level, bump.feeStroops);
+    }
+  };
+
+  const isBusy = loading || fetching;
+  const hasFees = feeEstimate && feeEstimate.totalFeeStroops > 0;
+
+  return (
+    <div className="rounded-2xl border border-slate-800 bg-slate-900/70 p-5 font-mono">
+      <div className="flex items-center justify-between mb-4">
+        <div className="flex items-center gap-2">
+          <Fuel className="h-4 w-4 text-cyan-400" />
+          <h3 className="text-sm font-bold text-slate-100 uppercase tracking-wider">
+            Network Fee Estimation
+          </h3>
+        </div>
+        {!rpcAvailable && (
+          <span className="text-[10px] text-amber-400 bg-amber-500/10 border border-amber-500/30 rounded px-2 py-0.5">
+            Estimated (RPC offline)
+          </span>
+        )}
+      </div>
+
+      {isBusy ? (
+        <div className="flex items-center justify-center py-8">
+          <div className="h-5 w-5 border-2 border-cyan-400 border-t-transparent rounded-full animate-spin" />
+        </div>
+      ) : hasFees ? (
+        <div className="space-y-4">
+          <div className="grid grid-cols-3 gap-3">
+            <div className="bg-slate-950/60 border border-slate-800 rounded-lg p-3 text-center">
+              <div className="flex items-center justify-center gap-1 text-[10px] text-slate-500 uppercase mb-1">
+                <Zap className="h-3 w-3" />
+                Resource Fee
+              </div>
+              <div className="text-sm font-bold text-cyan-400">
+                {stroopsToXlm(feeEstimate.minResourceFeeStroops)} XLM
+              </div>
+              <div className="text-[9px] text-slate-500 mt-0.5">
+                {feeEstimate.minResourceFeeStroops.toLocaleString()} stroops
+              </div>
+            </div>
+            <div className="bg-slate-950/60 border border-slate-800 rounded-lg p-3 text-center">
+              <div className="flex items-center justify-center gap-1 text-[10px] text-slate-500 uppercase mb-1">
+                <Gauge className="h-3 w-3" />
+                Classic Fee
+              </div>
+              <div className="text-sm font-bold text-slate-100">
+                {stroopsToXlm(feeEstimate.classicFeeStroops)} XLM
+              </div>
+              <div className="text-[9px] text-slate-500 mt-0.5">
+                {feeEstimate.classicFeeStroops.toLocaleString()} stroops
+              </div>
+            </div>
+            <div className="bg-slate-950/60 border border-slate-800 rounded-lg p-3 text-center">
+              <div className="flex items-center justify-center gap-1 text-[10px] text-slate-500 uppercase mb-1">
+                <DollarSign className="h-3 w-3" />
+                Total
+              </div>
+              <div className="text-sm font-bold text-emerald-400">
+                {feeEstimate.totalFeeXlm} XLM
+              </div>
+              <div className="text-[9px] text-slate-500 mt-0.5">
+                {feeEstimate.totalFeeStroops.toLocaleString()} stroops
+              </div>
+            </div>
+          </div>
+
+          {feeEstimate.surgeMultiplier > 1 && (
+            <div className="flex items-center gap-2 text-[11px] text-amber-400 bg-amber-500/5 border border-amber-500/20 rounded-lg px-3 py-2">
+              <TrendingUp className="h-3.5 w-3.5 shrink-0" />
+              <span>
+                Network surge active ({feeEstimate.surgeMultiplier}x multiplier) &mdash; fees may be higher than usual
+              </span>
+            </div>
+          )}
+
+          <div>
+            <div className="text-[10px] text-slate-500 uppercase mb-2">Fee Bump Options</div>
+            <div className="grid grid-cols-3 gap-2">
+              {feeEstimate.feeBumps.map((bump) => {
+                const isSelected = selectedBump === bump.label;
+                return (
+                  <button
+                    key={bump.label}
+                    type="button"
+                    disabled={isBusy}
+                    onClick={() => handleBumpSelect(bump)}
+                    className={`rounded-lg border px-3 py-2.5 text-left transition-all duration-150 ${
+                      isSelected
+                        ? 'border-cyan-500/50 bg-cyan-500/10 ring-1 ring-cyan-500/30'
+                        : 'border-slate-800 bg-slate-950/40 hover:border-slate-700 hover:bg-slate-950/60'
+                    }`}
+                  >
+                    <div className={`text-xs font-semibold ${isSelected ? 'text-cyan-400' : 'text-slate-300'}`}>
+                      {bump.label}
+                    </div>
+                    <div className={`text-sm font-bold mt-1 ${isSelected ? 'text-white' : 'text-slate-100'}`}>
+                      {bump.feeXlm} XLM
+                    </div>
+                    <div className="text-[9px] text-slate-500 mt-0.5">
+                      {bump.feeStroops.toLocaleString()} stroops
+                    </div>
+                  </button>
+                );
+              })}
+            </div>
+          </div>
+
+          <div className="border-t border-slate-800 pt-3">
+            <div className="flex items-center justify-between text-[10px] text-slate-500">
+              <span>Surge multiplier: {feeEstimate.surgeMultiplier}x</span>
+              <button
+                type="button"
+                onClick={loadFeeEstimate}
+                disabled={isBusy}
+                className="text-cyan-400 hover:text-cyan-300 transition-colors cursor-pointer"
+              >
+                Refresh
+              </button>
+            </div>
+          </div>
+        </div>
+      ) : (
+        <div className="text-center py-6">
+          <Fuel className="h-8 w-8 text-slate-700 mx-auto mb-2" />
+          <p className="text-xs text-slate-500">
+            Run a simulation to see network fee estimates
+          </p>
+        </div>
+      )}
+    </div>
+  );
+}
diff --git a/web/lib/sorobantypes.ts b/web/lib/sorobantypes.ts
index 16cff6dd..2643a5fd 100644
--- a/web/lib/sorobantypes.ts
+++ b/web/lib/sorobantypes.ts
@@ -216,3 +216,27 @@ export function generateMockResourceCost(): ResourceCost {
     transaction_size_bytes: Math.floor(Math.random() * 2 * 1024),
   };
 }
+
+export interface FeeBumpOption {
+  label: string;
+  multiplier: number;
+  feeStroops: number;
+  feeXlm: string;
+  description: string;
+}
+
+export interface FeeEstimate {
+  minResourceFeeStroops: number;
+  classicFeeStroops: number;
+  totalFeeStroops: number;
+  totalFeeXlm: string;
+  feeBumps: FeeBumpOption[];
+  networkFees: {
+    low: number;
+    medium: number;
+    high: number;
+  };
+  surgeMultiplier: number;
+}
+
+export type FeeBumpLevel = 'low' | 'medium' | 'high';
diff --git a/web/lib/stellarRpc.test.cjs b/web/lib/stellarRpc.test.cjs
new file mode 100644
index 00000000..e3ade4fb
--- /dev/null
+++ b/web/lib/stellarRpc.test.cjs
@@ -0,0 +1,223 @@
+// stellarRpc.test.cjs — unit tests for Stellar RPC fee estimation logic
+// Closes Issue #595
+// Runs with: node --test ./lib/stellarRpc.test.cjs
+
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const FeeBumpLevel = Object.freeze({
+  LOW: 'low',
+  MEDIUM: 'medium',
+  HIGH: 'high',
+});
+
+const BUMP_CONFIG = Object.freeze({
+  [FeeBumpLevel.LOW]: {
+    label: 'Low (Min)',
+    multiplier: 1.0,
+    description: 'Minimum fee, slower confirmation',
+  },
+  [FeeBumpLevel.MEDIUM]: {
+    label: 'Medium',
+    multiplier: 1.5,
+    description: 'Balanced speed and cost',
+  },
+  [FeeBumpLevel.HIGH]: {
+    label: 'High',
+    multiplier: 2.0,
+    description: 'Priority processing',
+  },
+});
+
+function stroopsToXlm(stroops) {
+  const xlm = stroops / 10_000_000;
+  if (xlm === 0) return '0';
+  if (xlm < 0.000001) return xlm.toFixed(9);
+  if (xlm < 0.001) return xlm.toFixed(7);
+  return xlm.toFixed(5);
+}
+
+function formatStroops(stroops) {
+  const xlm = stroops / 10_000_000;
+  return `${xlm.toFixed(7)} XLM`;
+}
+
+function estimateFees(resourceCostStroops, feeStats) {
+  const baseClassicFee = (feeStats && feeStats.min_ledger_fee) || 100;
+  const surge = (feeStats && feeStats.surge_multiplier) || 1;
+  const sorobanRate = (feeStats && feeStats.soroban_fee_rate) || 1;
+
+  const minResourceFeeStroops = resourceCostStroops;
+  const classicFeeStroops = baseClassicFee;
+  const baseTotal = minResourceFeeStroops + classicFeeStroops;
+
+  const surgeMultiplier = surge;
+
+  const feeBumps = Object.values(BUMP_CONFIG).map((cfg) => {
+    const feeStroops = Math.ceil(baseTotal * cfg.multiplier * sorobanRate);
+    return {
+      label: cfg.label,
+      multiplier: cfg.multiplier,
+      feeStroops,
+      feeXlm: stroopsToXlm(feeStroops),
+      description: cfg.description,
+    };
+  });
+
+  return {
+    minResourceFeeStroops,
+    classicFeeStroops,
+    totalFeeStroops: baseTotal,
+    totalFeeXlm: stroopsToXlm(baseTotal),
+    feeBumps,
+    networkFees: {
+      low: feeBumps[0].feeStroops,
+      medium: feeBumps[1].feeStroops,
+      high: feeBumps[2].feeStroops,
+    },
+    surgeMultiplier,
+  };
+}
+
+// ── stroopsToXlm Tests ────────────────────────────────────────────────────────
+
+test('stroopsToXlm: returns 0 for zero stroops', () => {
+  assert.equal(stroopsToXlm(0), '0');
+});
+
+test('stroopsToXlm: converts 10_000_000 stroops to 1 XLM', () => {
+  assert.equal(stroopsToXlm(10_000_000), '1.00000');
+});
+
+test('stroopsToXlm: converts 100 stroops (very small amount)', () => {
+  const result = stroopsToXlm(100);
+  assert.ok(result.startsWith('0.00001'));
+});
+
+test('stroopsToXlm: converts 1_000_000 stroops to 0.1 XLM', () => {
+  assert.equal(stroopsToXlm(1_000_000), '0.10000');
+});
+
+test('stroopsToXlm: converts 5_000_000 stroops to 0.5 XLM', () => {
+  assert.equal(stroopsToXlm(5_000_000), '0.50000');
+});
+
+// ── estimateFees Tests ────────────────────────────────────────────────────────
+
+test('estimateFees: computes base fee breakdown from resource cost', () => {
+  const resourceCost = 500_000;
+  const stats = {
+    min_ledger_fee: 100,
+    surge_multiplier: 1,
+    soroban_fee_rate: 1,
+  };
+
+  const result = estimateFees(resourceCost, stats);
+
+  assert.equal(result.minResourceFeeStroops, 500_000);
+  assert.equal(result.classicFeeStroops, 100);
+  assert.equal(result.totalFeeStroops, 500_100);
+  assert.ok(result.totalFeeXlm.length > 0);
+});
+
+test('estimateFees: generates three fee bump options', () => {
+  const result = estimateFees(500_000, null);
+
+  assert.equal(result.feeBumps.length, 3);
+  assert.equal(result.feeBumps[0].multiplier, 1.0);
+  assert.equal(result.feeBumps[1].multiplier, 1.5);
+  assert.equal(result.feeBumps[2].multiplier, 2.0);
+});
+
+test('estimateFees: fee bumps increase proportionally', () => {
+  const result = estimateFees(1_000_000, null);
+
+  const low = result.networkFees.low;
+  const medium = result.networkFees.medium;
+  const high = result.networkFees.high;
+
+  assert.ok(low < medium, 'Low fee should be less than medium');
+  assert.ok(medium < high, 'Medium fee should be less than high');
+  assert.ok(high >= low * 2 || high >= low * 1.8, 'High should be roughly 2x low');
+});
+
+test('estimateFees: applies surge multiplier when provided', () => {
+  const baseResourceCost = 500_000;
+  const normalResult = estimateFees(baseResourceCost, {
+    min_ledger_fee: 100,
+    surge_multiplier: 1,
+    soroban_fee_rate: 1,
+  });
+
+  const surgedResult = estimateFees(baseResourceCost, {
+    min_ledger_fee: 100,
+    surge_multiplier: 5,
+    soroban_fee_rate: 2,
+  });
+
+  assert.ok(surgedResult.surgeMultiplier > 1);
+  assert.ok(surgedResult.networkFees.low > normalResult.networkFees.low);
+});
+
+test('estimateFees: returns valid XLM strings for all fee bump options', () => {
+  const result = estimateFees(750_000, null);
+  for (const bump of result.feeBumps) {
+    assert.ok(typeof bump.feeXlm === 'string');
+    assert.ok(bump.feeXlm.length > 0);
+    assert.ok(bump.feeXlm.includes('.') || bump.feeXlm === '0');
+  }
+});
+
+test('estimateFees: handles zero resource cost gracefully', () => {
+  const result = estimateFees(0, null);
+
+  assert.equal(result.minResourceFeeStroops, 0);
+  assert.equal(result.classicFeeStroops, 100);
+  assert.equal(result.totalFeeStroops, 100);
+  assert.ok(result.feeBumps.length === 3);
+});
+
+test('estimateFees: handles very large resource costs', () => {
+  const largeCost = 100_000_000_000;
+  const result = estimateFees(largeCost, null);
+
+  assert.equal(result.minResourceFeeStroops, largeCost);
+  assert.ok(result.totalFeeStroops > largeCost);
+  assert.ok(result.feeBumps[2].feeStroops > result.feeBumps[0].feeStroops);
+});
+
+test('estimateFees: uses default classic fee when no fee stats provided', () => {
+  const result = estimateFees(1000, null);
+  assert.equal(result.classicFeeStroops, 100);
+});
+
+test('estimateFees: uses custom classic fee from fee stats', () => {
+  const result = estimateFees(1000, {
+    min_ledger_fee: 500,
+    surge_multiplier: 1,
+    soroban_fee_rate: 1,
+  });
+  assert.equal(result.classicFeeStroops, 500);
+});
+
+test('estimateFees: classic fee + resource fee sum correctly', () => {
+  const resourceCost = 1000;
+  const result = estimateFees(resourceCost, {
+    min_ledger_fee: 200,
+    surge_multiplier: 1,
+    soroban_fee_rate: 1,
+  });
+
+  assert.equal(result.totalFeeStroops, resourceCost + 200);
+  assert.equal(result.minResourceFeeStroops + result.classicFeeStroops, result.totalFeeStroops);
+});
+
+// ── formatStroops Tests ───────────────────────────────────────────────────────
+
+test('formatStroops: formats output string correctly', () => {
+  const result = formatStroops(10_000_000);
+  assert.ok(result.includes('XLM'));
+  assert.ok(result.includes('1.0000000'));
+});
diff --git a/web/lib/stellarRpc.ts b/web/lib/stellarRpc.ts
new file mode 100644
index 00000000..00117bce
--- /dev/null
+++ b/web/lib/stellarRpc.ts
@@ -0,0 +1,188 @@
+/**
+ * Stellar RPC client for fee estimation.
+ *
+ * Communicates with Soroban RPC endpoints to retrieve network fee stats and
+ * compute transaction fee estimates from resource-cost data.
+ */
+
+import type { FeeBumpOption, FeeEstimate } from './sorobantypes';
+
+const RPC_TIMEOUT_MS = 10_000;
+
+export interface FeeStatsResponse {
+  soroban_fee_charged: FeeStatDistribution;
+  soroban_fee_rate: number;
+  surge_multiplier: number;
+  classic_fee_charged: FeeStatDistribution;
+  classic_fee_rate: number;
+  min_ledger_fee: number;
+}
+
+export interface FeeStatDistribution {
+  max: number;
+  min: number;
+  mode: number;
+  p10: number;
+  p20: number;
+  p30: number;
+  p40: number;
+  p50: number;
+  p60: number;
+  p70: number;
+  p80: number;
+  p90: number;
+  p95: number;
+  p99: number;
+}
+
+function parseStroops(value: string | number): number {
+  if (typeof value === 'number') return value;
+  const parsed = Number(value);
+  return Number.isFinite(parsed) ? parsed : 0;
+}
+
+export function stroopsToXlm(stroops: number): string {
+  const xlm = stroops / 10_000_000;
+  if (xlm === 0) return '0';
+  if (xlm < 0.000001) return xlm.toFixed(9);
+  if (xlm < 0.001) return xlm.toFixed(7);
+  return xlm.toFixed(5);
+}
+
+export function formatStroops(stroops: number): string {
+  const xlm = stroops / 10_000_000;
+  return `${xlm.toFixed(7)} XLM`;
+}
+
+async function rpcCall<T>(
+  rpcUrl: string,
+  method: string,
+  params?: unknown,
+): Promise<T> {
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), RPC_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(rpcUrl, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        jsonrpc: '2.0',
+        id: 1,
+        method,
+        params: params ?? {},
+      }),
+      signal: controller.signal,
+    });
+
+    if (!response.ok) {
+      throw new Error(`RPC HTTP ${response.status}: ${response.statusText}`);
+    }
+
+    const data = await response.json();
+    if (data.error) {
+      throw new Error(`RPC error [${data.error.code}]: ${data.error.message}`);
+    }
+
+    return data.result as T;
+  } finally {
+    clearTimeout(timer);
+  }
+}
+
+export async function fetchFeeStats(rpcUrl: string): Promise<FeeStatsResponse> {
+  const result: Record<string, unknown> = await rpcCall(rpcUrl, 'getFeeStats');
+
+  const parseDist = (prefix: string): FeeStatDistribution => {
+    const v = (key: string) => parseStroops(result[`${prefix}_${key}`] as string | number);
+    return {
+      max: v('max'),
+      min: v('min'),
+      mode: v('mode'),
+      p10: v('p10'),
+      p20: v('p20'),
+      p30: v('p30'),
+      p40: v('p40'),
+      p50: v('p50'),
+      p60: v('p60'),
+      p70: v('p70'),
+      p80: v('p80'),
+      p90: v('p90'),
+      p95: v('p95'),
+      p99: v('p99'),
+    };
+  };
+
+  return {
+    soroban_fee_charged: parseDist('soroban_fee_charged'),
+    soroban_fee_rate: parseStroops(result.soroban_fee_rate as string | number),
+    surge_multiplier: parseStroops(result.surge_multiplier as string | number),
+    classic_fee_charged: parseDist('classic_fee_charged'),
+    classic_fee_rate: parseStroops(result.classic_fee_rate as string | number),
+    min_ledger_fee: parseStroops(result.last_ledger_base_fee as string | number),
+  };
+}
+
+export enum FeeBumpLevel {
+  LOW = 'low',
+  MEDIUM = 'medium',
+  HIGH = 'high',
+}
+
+const BUMP_CONFIG: Record<FeeBumpLevel, { label: string; multiplier: number; description: string }> = {
+  [FeeBumpLevel.LOW]: {
+    label: 'Low (Min)',
+    multiplier: 1.0,
+    description: 'Minimum fee, slower confirmation',
+  },
+  [FeeBumpLevel.MEDIUM]: {
+    label: 'Medium',
+    multiplier: 1.5,
+    description: 'Balanced speed and cost',
+  },
+  [FeeBumpLevel.HIGH]: {
+    label: 'High',
+    multiplier: 2.0,
+    description: 'Priority processing',
+  },
+};
+
+export function estimateFees(
+  resourceCostStroops: number,
+  feeStats?: FeeStatsResponse | null,
+): FeeEstimate {
+  const baseClassicFee = feeStats?.min_ledger_fee ?? 100;
+  const surge = feeStats?.surge_multiplier ?? 1;
+  const sorobanRate = feeStats?.soroban_fee_rate ?? 1;
+
+  const minResourceFeeStroops = resourceCostStroops;
+  const classicFeeStroops = baseClassicFee;
+  const baseTotal = minResourceFeeStroops + classicFeeStroops;
+
+  const surgeMultiplier = surge;
+
+  const feeBumps: FeeBumpOption[] = Object.values(BUMP_CONFIG).map((cfg) => {
+    const feeStroops = Math.ceil(baseTotal * cfg.multiplier * sorobanRate);
+    return {
+      label: cfg.label,
+      multiplier: cfg.multiplier,
+      feeStroops,
+      feeXlm: stroopsToXlm(feeStroops),
+      description: cfg.description,
+    };
+  });
+
+  return {
+    minResourceFeeStroops,
+    classicFeeStroops,
+    totalFeeStroops: baseTotal,
+    totalFeeXlm: stroopsToXlm(baseTotal),
+    feeBumps,
+    networkFees: {
+      low: feeBumps[0].feeStroops,
+      medium: feeBumps[1].feeStroops,
+      high: feeBumps[2].feeStroops,
+    },
+    surgeMultiplier,
+  };
+}
diff --git a/web/pages/index.tsx b/web/pages/index.tsx
index f74b8820..06652808 100644
--- a/web/pages/index.tsx
+++ b/web/pages/index.tsx
@@ -14,6 +14,7 @@ import { NutritionLabelSkeleton } from "../components/NutritionLabelSkeleton";
 import { ResourceHeatmap } from "../components/ResourceHeatmap";
 import { ResultViewer } from "../components/Resultviewer";
 import { ResultViewerSkeleton } from "../components/ResultViewerSkeleton";
+import { FeeEstimationPreview } from "../components/FeeEstimationPreview";
 import { UploadZone } from "../components/upload-zone";
 import { CopyButton } from "../components/CopyButton";
 import { useNetwork } from "../context/NetworkContext";
@@ -177,7 +178,7 @@ export default function Home() {
                           ledger_read_bytes: analysisReport.ledger_read_bytes,
                           ledger_write_bytes: analysisReport.ledger_write_bytes,
                           transaction_size_bytes: analysisReport.transaction_size_bytes,
-                          cost_stroops: (analysisReport as any).cost_stroops,
+                          cost_stroops: analysisReport.cost_stroops,
                           state_snapshot: currentResult.stateSnapshot
                         }} />
                       </div>
@@ -197,8 +198,16 @@ export default function Home() {
                           ledger_read_bytes={analysisReport.ledger_read_bytes}
                           ledger_write_bytes={analysisReport.ledger_write_bytes}
                           transaction_size_bytes={analysisReport.transaction_size_bytes}
-                          cost_stroops={(analysisReport as any).cost_stroops}
-                          testnetAverages={(analysisReport as any).testnet_averages}
+                          cost_stroops={analysisReport.cost_stroops}
+                          testnetAverages={analysisReport.testnet_averages}
+                        />
+                      </div>
+                    )}
+                    {analysisReport && analysisReport.cost_stroops !== undefined && (
+                      <div className="mt-4">
+                        <FeeEstimationPreview
+                          costStroops={analysisReport.cost_stroops}
+                          loading={loading}
                         />
                       </div>
                     )}