diff --git a/Cargo.lock b/Cargo.lock
index 40eb240..f9eb1bc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -39,6 +39,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anes"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
+
 [[package]]
 name = "anstream"
 version = "0.6.21"
@@ -278,6 +284,12 @@ version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b35204fbdc0b3f4446b89fc1ac2cf84a8a68971995d0bf2e925ec7cd960f9cb3"
 
+[[package]]
+name = "cast"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
+
 [[package]]
 name = "cc"
 version = "1.2.54"
@@ -308,6 +320,33 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "ciborium"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42e69ffd6f0917f5c029256a24d0161db17cea3997d185db0d35926308770f0e"
+dependencies = [
+ "ciborium-io",
+ "ciborium-ll",
+ "serde",
+]
+
+[[package]]
+name = "ciborium-io"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05afea1e0a06c9be33d539b876f1ce3692f4afea2cb41f740e7743225ed1c757"
+
+[[package]]
+name = "ciborium-ll"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57663b653d948a338bfb3eeba9bb2fd5fcfaecb9e199e87e1eda4d9e8b240fd9"
+dependencies = [
+ "ciborium-io",
+ "half",
+]
+
 [[package]]
 name = "clap"
 version = "4.5.54"
@@ -409,6 +448,61 @@ version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19d374276b40fb8bbdee95aef7c7fa6b5316ec764510eb64b8dd0e2ed0d7e7f5"
 
+[[package]]
+name = "criterion"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2b12d017a929603d80db1831cd3a24082f8137ce19c69e6447f54f5fc8d692f"
+dependencies = [
+ "anes",
+ "cast",
+ "ciborium",
+ "clap",
+ "criterion-plot",
+ "is-terminal",
+ "itertools",
+ "num-traits",
+ "once_cell",
+ "oorandom",
+ "plotters",
+ "rayon",
+ "regex",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "tinytemplate",
+ "walkdir",
+]
+
+[[package]]
+name = "criterion-plot"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b50826342786a51a89e2da3a28f1c32b06e387201bc2d19791f622c673706b1"
+dependencies = [
+ "cast",
+ "itertools",
+]
+
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-queue"
 version = "0.3.12"
@@ -424,6 +518,12 @@ version = "0.8.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
 
+[[package]]
+name = "crunchy"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "460fbee9c2c2f33933d720630a6a0bac33ba7053db5344fac858d4b8952d77d5"
+
 [[package]]
 name = "crypto-common"
 version = "0.1.7"
@@ -804,6 +904,17 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "half"
+version = "2.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ea2d84b969582b4b1864a92dc5d27cd2b77b622a8d79306834f1be5ba20d84b"
+dependencies = [
+ "cfg-if",
+ "crunchy",
+ "zerocopy",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.14.5"
@@ -1202,12 +1313,32 @@ version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "469fb0b9cefa57e3ef31275ee7cacb78f2fdca44e4765491884a2b119d4eb130"
 
+[[package]]
+name = "is-terminal"
+version = "0.4.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3640c1c38b8e4e43584d8df18be5fc6b0aa314ce6ebf51b53313d4306cca8e46"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.17"
@@ -1452,6 +1583,12 @@ version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
+[[package]]
+name = "oorandom"
+version = "11.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6790f58c7ff633d8771f42965289203411a5e5c68388703c06e14f24770b41e"
+
 [[package]]
 name = "openssl"
 version = "0.10.75"
@@ -1585,6 +1722,34 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
+[[package]]
+name = "plotters"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aeb6f403d7a4911efb1e33402027fc44f29b5bf6def3effcc22d7bb75f2b747"
+dependencies = [
+ "num-traits",
+ "plotters-backend",
+ "plotters-svg",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "plotters-backend"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df42e13c12958a16b3f7f4386b9ab1f3e7933914ecea48da7139435263a4172a"
+
+[[package]]
+name = "plotters-svg"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51bae2ac328883f7acdfea3d66a7c35751187f870bc81f94563733a154d7a670"
+dependencies = [
+ "plotters-backend",
+]
+
 [[package]]
 name = "potential_utf"
 version = "0.1.4"
@@ -1782,6 +1947,26 @@ dependencies = [
  "rand_core 0.9.5",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22e18b0f0062d30d4230b2e85ff77fdfe4326feb054b9783a3460d8435c8ab91"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.5.18"
@@ -1941,6 +2126,15 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a50f4cf475b65d88e057964e0e9bb1f0aa9bbb2036dc65c64596b42932536984"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "schannel"
 version = "0.1.28"
@@ -2379,6 +2573,7 @@ name = "stellar-devkit"
 version = "0.1.0"
 dependencies = [
  "axum",
+ "criterion",
  "serde_json",
  "thiserror",
  "tokio",
@@ -2553,6 +2748,16 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "tinytemplate"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be4d6b5f19ff7664e8c98d03e2139cb510db9b0a60b55f8e8709b689d939b6bc"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.10.0"
@@ -2868,6 +3073,16 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "317211a0dc0ceedd78fb2ca9a44aed3d7b9b26f81870d485c07122b4350673b7"
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -2983,6 +3198,15 @@ dependencies = [
  "wasite",
 ]
 
+[[package]]
+name = "winapi-util"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "windows-core"
 version = "0.62.2"
diff --git a/packages/devkit/Cargo.toml b/packages/devkit/Cargo.toml
index 15e8fc1..1326ef9 100644
--- a/packages/devkit/Cargo.toml
+++ b/packages/devkit/Cargo.toml
@@ -12,3 +12,8 @@ tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
 
 [dev-dependencies]
 serde_json = "1"
+criterion = { version = "0.5", features = ["html_reports"] }
+
+[[bench]]
+name = "fee_model_bench"
+harness = false
diff --git a/packages/devkit/benches/fee_model_bench.rs b/packages/devkit/benches/fee_model_bench.rs
new file mode 100644
index 0000000..7d0f787
--- /dev/null
+++ b/packages/devkit/benches/fee_model_bench.rs
@@ -0,0 +1,15 @@
+use criterion::{criterion_group, criterion_main, Criterion};
+use stellar_devkit::simulation::fee_model::{FeeModel, FeeModelConfig};
+
+fn bench_generate_100k(c: &mut Criterion) {
+    let config = FeeModelConfig {
+        ledger_count: 100_000,
+        ..Default::default()
+    };
+    c.bench_function("fee_model_generate_100k", |b| {
+        b.iter(|| FeeModel::generate(&config))
+    });
+}
+
+criterion_group!(benches, bench_generate_100k);
+criterion_main!(benches);
diff --git a/packages/devkit/src/cli/export.rs b/packages/devkit/src/cli/export.rs
index 16350ae..4454a41 100644
--- a/packages/devkit/src/cli/export.rs
+++ b/packages/devkit/src/cli/export.rs
@@ -1,2 +1,21 @@
+use crate::simulation::fee_model::FeePoint;
+use std::fmt::Write as FmtWrite;
+
 /// Exports devkit results to external formats.
 pub struct Export;
+
+impl Export {
+    /// Serialize fee points to CSV string with columns: timestamp,fee,ledger,is_spike.
+    pub fn to_csv(points: &[FeePoint]) -> String {
+        let mut out = String::from("timestamp,fee,ledger,is_spike\n");
+        for p in points {
+            writeln!(out, "{},{},{},{}", p.timestamp, p.fee, p.ledger, p.is_spike).unwrap();
+        }
+        out
+    }
+
+    /// Write fee points to a CSV file.
+    pub fn write_csv(points: &[FeePoint], path: &std::path::Path) -> std::io::Result<()> {
+        std::fs::write(path, Self::to_csv(points))
+    }
+}
diff --git a/packages/devkit/src/harness/scenarios/mod.rs b/packages/devkit/src/harness/scenarios/mod.rs
index 3e0f82a..ce3551c 100644
--- a/packages/devkit/src/harness/scenarios/mod.rs
+++ b/packages/devkit/src/harness/scenarios/mod.rs
@@ -27,6 +27,8 @@ impl ScenarioRotator {
     }
 }
 
+use std::path::Path;
+
 /// Loads a scenario JSON file from the given path and returns its contents.
 pub fn load_from_file(path: &Path) -> std::io::Result<String> {
     std::fs::read_to_string(path)
diff --git a/packages/devkit/src/simulation/fee_model.rs b/packages/devkit/src/simulation/fee_model.rs
index ba26726..59277a1 100644
--- a/packages/devkit/src/simulation/fee_model.rs
+++ b/packages/devkit/src/simulation/fee_model.rs
@@ -1,7 +1,71 @@
+/// A single simulated fee data point.
+#[derive(Debug, Clone)]
+pub struct FeePoint {
+    pub timestamp: u64,
+    pub fee: u64,
+    pub ledger: u64,
+    pub is_spike: bool,
+}
+
+/// Configuration for a single simulation scenario.
+#[derive(Debug, Clone)]
+pub struct FeeModelConfig {
+    pub base_fee: u64,
+    pub ledger_count: u64,
+    pub spike_probability: f64,
+    pub spike_multiplier: u64,
+}
+
+impl Default for FeeModelConfig {
+    fn default() -> Self {
+        Self {
+            base_fee: 100,
+            ledger_count: 100,
+            spike_probability: 0.05,
+            spike_multiplier: 10,
+        }
+    }
+}
+
 /// Models for simulating Stellar transaction fee behaviour.
 pub struct FeeModel;
 
 impl FeeModel {
+    /// Generate fee points for a single config.
+    pub fn generate(config: &FeeModelConfig) -> Vec<FeePoint> {
+        let mut points = Vec::with_capacity(config.ledger_count as usize);
+        let mut pseudo = 6364136223846793005u64;
+        for i in 0..config.ledger_count {
+            pseudo = pseudo.wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407);
+            let rand_f = (pseudo >> 33) as f64 / u32::MAX as f64;
+            let is_spike = rand_f < config.spike_probability;
+            let fee = if is_spike {
+                config.base_fee * config.spike_multiplier
+            } else {
+                config.base_fee
+            };
+            points.push(FeePoint { timestamp: i * 5, fee, ledger: i + 1, is_spike });
+        }
+        points
+    }
+
+    /// Run multiple scenarios sequentially and return combined output.
+    pub fn run_scenarios(configs: &[FeeModelConfig]) -> Vec<FeePoint> {
+        let mut all = Vec::new();
+        let mut ledger_offset = 0u64;
+        let mut time_offset = 0u64;
+        for config in configs {
+            let mut points = Self::generate(config);
+            for p in &mut points {
+                p.ledger += ledger_offset;
+                p.timestamp += time_offset;
+            }
+            let last = points.last().map(|p| (p.ledger, p.timestamp)).unwrap_or((0, 0));
+            ledger_offset = last.0;
+            time_offset = last.1 + 5;
+            all.extend(points);
+        }
+        all
     /// Generates `count` baseline fee values (in stroops) at the Stellar minimum (100).
     pub fn baseline(count: usize) -> Vec<f64> {
         vec![100.0; count]
diff --git a/packages/devkit/src/simulation/network_load.rs b/packages/devkit/src/simulation/network_load.rs
index 13c02d6..9ca24ef 100644
--- a/packages/devkit/src/simulation/network_load.rs
+++ b/packages/devkit/src/simulation/network_load.rs
@@ -1,2 +1,17 @@
 /// Generates synthetic network load profiles for simulation.
 pub struct NetworkLoad;
+
+impl NetworkLoad {
+    /// Returns a fee multiplier (1.0–3.0) based on hour of day (0–23).
+    /// Peak hours (8–20) have higher fees simulating daytime congestion.
+    pub fn diurnal_multiplier(hour: u8) -> f64 {
+        // Simple sinusoidal: peak at hour 14 (2pm UTC), trough at hour 2 (2am UTC)
+        let angle = std::f64::consts::PI * (hour as f64 - 2.0) / 12.0;
+        1.0 + angle.sin().max(0.0) * 2.0
+    }
+
+    /// Apply diurnal multiplier to a base fee given the hour of day.
+    pub fn diurnal_fee(base_fee: u64, hour: u8) -> u64 {
+        (base_fee as f64 * Self::diurnal_multiplier(hour)).round() as u64
+    }
+}