diff --git a/yarn-project/aztec/bootstrap.sh b/yarn-project/aztec/bootstrap.sh
index c27fba277781..fadce4199f06 100755
--- a/yarn-project/aztec/bootstrap.sh
+++ b/yarn-project/aztec/bootstrap.sh
@@ -12,6 +12,8 @@ function test_cmds {
   # All CLI tests share test/mixed-workspace/target so they must run sequentially
   # in a single jest invocation (--runInBand is set by run_test.sh).
   echo "$hash:ISOLATE=1:NAME=aztec/cli NARGO=$NARGO BB=$BB PROFILER_PATH=$PROFILER_PATH yarn-project/scripts/run_test.sh aztec/src/cli"
+  # setupLocalNetwork smoke test: spins up anvil + an in-process node (network usage ⇒ ISOLATE).
+  echo "$hash:ISOLATE=1:NAME=aztec/testing yarn-project/scripts/run_test.sh aztec/src/testing/local-network.test.ts"
 }
 
 case "$cmd" in
diff --git a/yarn-project/aztec/src/local-network/local-network.ts b/yarn-project/aztec/src/local-network/local-network.ts
index eefbd37ed8df..f24bc28abd14 100644
--- a/yarn-project/aztec/src/local-network/local-network.ts
+++ b/yarn-project/aztec/src/local-network/local-network.ts
@@ -88,6 +88,8 @@ export type LocalNetworkConfig = AztecNodeConfig & {
   l1Mnemonic: string;
   /** Whether to deploy test accounts on local network start.*/
   testAccounts: boolean;
+  /** Override the default per-address fee juice granted at genesis to funded addresses. */
+  initialAccountFeeJuice: Fr;
 };
 
 /**
@@ -176,7 +178,10 @@ export async function createLocalNetwork(config: Partial<LocalNetworkConfig> = {
     ...(initialAccounts.length ? [bananaFPC, sponsoredFPC] : []),
     ...prefundAddresses,
   ];
-  const { genesisArchiveRoot, genesis, fundingNeeded } = await getGenesisValues(fundedAddresses);
+  const { genesisArchiveRoot, genesis, fundingNeeded } = await getGenesisValues(
+    fundedAddresses,
+    config.initialAccountFeeJuice,
+  );
 
   const dateProvider = new TestDateProvider();
 
diff --git a/yarn-project/aztec/src/testing/index.ts b/yarn-project/aztec/src/testing/index.ts
index 0155a48144fd..6459e351146b 100644
--- a/yarn-project/aztec/src/testing/index.ts
+++ b/yarn-project/aztec/src/testing/index.ts
@@ -1,4 +1,5 @@
 export { EthCheatCodes, RollupCheatCodes } from '@aztec/ethereum/test';
 export { CheatCodes } from './cheat_codes.js';
 export { EpochTestSettler } from './epoch_test_settler.js';
+export { setupLocalNetwork, TEST_FEE_PADDING, type LocalNetwork, type LocalNetworkOptions } from './local-network.js';
 export { getTokenAllowedSetupFunctions } from './token_allowed_setup.js';
diff --git a/yarn-project/aztec/src/testing/local-network.test.ts b/yarn-project/aztec/src/testing/local-network.test.ts
new file mode 100644
index 000000000000..20efcde3ca60
--- /dev/null
+++ b/yarn-project/aztec/src/testing/local-network.test.ts
@@ -0,0 +1,55 @@
+import { getInitialTestAccountsData } from '@aztec/accounts/testing';
+import { TokenContract } from '@aztec/noir-contracts.js/Token';
+import { EmbeddedWallet } from '@aztec/wallets/embedded';
+
+import { TEST_FEE_PADDING, setupLocalNetwork } from './local-network.js';
+
+describe('setupLocalNetwork', () => {
+  it('serves a live node on a random L1 port and tears down cleanly', async () => {
+    const net = await setupLocalNetwork();
+    try {
+      const info = await net.node.getNodeInfo();
+      expect(info.l1ContractAddresses.rollupAddress).toBeDefined();
+      expect(await net.node.getBlockNumber()).toBeGreaterThanOrEqual(0);
+      expect(net.l1ChainId).toBe(31337);
+      // OS-assigned ephemeral port, never the fixed default 8545.
+      expect(net.l1RpcUrl).toMatch(/^http:\/\/127\.0\.0\.1:\d+$/);
+      expect(net.l1RpcUrl).not.toContain(':8545');
+    } finally {
+      await net.stop();
+    }
+  }, 300_000);
+
+  it('runs two networks in parallel on distinct ports', async () => {
+    const [a, b] = await Promise.all([setupLocalNetwork(), setupLocalNetwork()]);
+    try {
+      expect(a.l1RpcUrl).not.toEqual(b.l1RpcUrl);
+      expect(await a.node.getBlockNumber()).toBeGreaterThanOrEqual(0);
+      expect(await b.node.getBlockNumber()).toBeGreaterThanOrEqual(0);
+    } finally {
+      await Promise.all([a.stop(), b.stop()]);
+    }
+  }, 300_000);
+
+  it('pre-funds addresses at genesis so they can pay for their own txs', async () => {
+    const [alice] = await getInitialTestAccountsData();
+    const net = await setupLocalNetwork({ fundedAddresses: [alice.address] });
+    try {
+      const wallet = await EmbeddedWallet.create(net.node, {
+        ephemeral: true,
+        pxeConfig: { proverEnabled: false },
+      });
+      await wallet.createSchnorrInitializerlessAccount(alice.secret, alice.salt, alice.signingKey);
+      wallet.setMinFeePadding(TEST_FEE_PADDING);
+
+      const { contract } = await TokenContract.deploy(wallet, alice.address, 'TokenName', 'TKN', 18).send({
+        from: alice.address,
+      });
+      expect(contract.address).toBeDefined();
+
+      await wallet.stop();
+    } finally {
+      await net.stop();
+    }
+  }, 300_000);
+});
diff --git a/yarn-project/aztec/src/testing/local-network.ts b/yarn-project/aztec/src/testing/local-network.ts
new file mode 100644
index 000000000000..9bceae67a66c
--- /dev/null
+++ b/yarn-project/aztec/src/testing/local-network.ts
@@ -0,0 +1,93 @@
+import type { AztecNodeService } from '@aztec/aztec-node';
+import type { AztecNodeConfig } from '@aztec/aztec-node/config';
+import type { Fr } from '@aztec/aztec.js/fields';
+import { ensureAztecBinsInPath, startAnvil } from '@aztec/ethereum/test';
+import type { AztecAddress } from '@aztec/stdlib/aztec-address';
+
+import { foundry } from 'viem/chains';
+
+import { createLocalNetwork } from '../local-network/local-network.js';
+
+/** A running in-process local network: an inline Aztec node backed by its own anvil L1. */
+export interface LocalNetwork {
+  /** Fully-synced Aztec node, ready to serve client requests. */
+  node: AztecNodeService;
+  /** RPC URL of the spawned anvil instance. */
+  l1RpcUrl: string;
+  /** Chain id used on L1 (foundry's default 31337). */
+  l1ChainId: number;
+  /** Stops every process started by the fixture: node and anvil. */
+  stop: () => Promise<void>;
+}
+
+/** Options for {@link setupLocalNetwork}. */
+export interface LocalNetworkOptions {
+  /**
+   * Addresses that should hold fee juice at genesis. Saves each of these the round-trip of bridging
+   * + claiming fee juice before they can pay for gas.
+   */
+  fundedAddresses?: AztecAddress[];
+  /** Override the default per-address genesis fee juice granted to {@link fundedAddresses}. */
+  initialAccountFeeJuice?: Fr;
+  /** Node config overrides, e.g. `realProofs`, `aztecEpochDuration`, `p2pEnabled`. */
+  config?: Partial<AztecNodeConfig>;
+  /** anvil block time in seconds. Omit for automine (the default). */
+  l1BlockTime?: number;
+}
+
+/**
+ * Spin up an in-process local network with the given addresses pre-funded.
+ *
+ * Each call spawns its own anvil on an OS-assigned random port and runs the Aztec node inline via
+ * the same {@link createLocalNetwork} codepath that backs `aztec start --local-network` (with the
+ * sandbox account/FPC/token setup skipped). Distinct ports let independent suites run in parallel.
+ * The caller must `await result.stop()` in its teardown.
+ *
+ * Requires an `aztec-up`-installed Foundry toolchain (`anvil`/`forge`/`solc`) reachable on `PATH`;
+ * {@link ensureAztecBinsInPath} splices the standard aztec-up bin directories in automatically.
+ */
+export async function setupLocalNetwork(opts: LocalNetworkOptions = {}): Promise<LocalNetwork> {
+  // `deployAztecL1Contracts` shells out to bare `forge`/`solc`; make the aztec-up bins reachable
+  // before anything spawns them. Idempotent, and also called inside `startAnvil`.
+  ensureAztecBinsInPath();
+
+  // `--port 0` → anvil binds an ephemeral port that `startAnvil` reads back, so parallel suites
+  // never collide on a fixed port.
+  const { rpcUrl, stop: stopAnvil } = await startAnvil({ port: 0, l1BlockTime: opts.l1BlockTime });
+
+  try {
+    const { node, stop: stopNode } = await createLocalNetwork(
+      {
+        ...opts.config,
+        l1RpcUrls: [rpcUrl],
+        testAccounts: false,
+        prefundAddresses: (opts.fundedAddresses ?? []).map(a => a.toString()),
+        initialAccountFeeJuice: opts.initialAccountFeeJuice,
+      },
+      () => {},
+    );
+
+    return {
+      node,
+      l1RpcUrl: rpcUrl,
+      l1ChainId: foundry.id,
+      stop: async () => {
+        await stopNode();
+        await stopAnvil();
+      },
+    };
+  } catch (err) {
+    await stopAnvil();
+    throw err;
+  }
+}
+
+/**
+ * Min-fee padding multiplier for test wallets sending txs against {@link setupLocalNetwork}. The
+ * automine sequencer builds one block per tx and advances L1 time in big jumps, so the network's
+ * congestion base fee can swing sharply between the wallet's fee estimate and the block the tx
+ * actually lands in. The default wallet padding isn't enough and trips
+ * `maxFeesPerGas.feePerL2Gas must be >= gasFees.feePerL2Gas`. Apply via
+ * `wallet.setMinFeePadding(TEST_FEE_PADDING)` on every test wallet that sends txs.
+ */
+export const TEST_FEE_PADDING = 30;
diff --git a/yarn-project/ethereum/scripts/anvil_kill_wrapper.sh b/yarn-project/ethereum/scripts/anvil_kill_wrapper.sh
deleted file mode 100755
index 629750efda21..000000000000
--- a/yarn-project/ethereum/scripts/anvil_kill_wrapper.sh
+++ /dev/null
@@ -1,51 +0,0 @@
-#!/usr/bin/env bash
-
-# Function to get the PPID in macOS
-get_ppid_macos() {
-  ps -j $$ | awk 'NR==2 {print $3}'
-}
-
-# Function to get the PPID in Linux
-get_ppid_linux() {
-  awk '{print $4}' /proc/$$/stat
-}
-
-# Function to check if a process is alive in macOS
-is_process_alive_macos() {
-  ps -p $1 > /dev/null 2>&1
-}
-
-# Function to check if a process is alive in Linux
-is_process_alive_linux() {
-  [ -d /proc/$1 ]
-}
-
-
-# Determine the operating system and call the appropriate function
-if [[ "$OSTYPE" == "darwin"* ]]; then
-  PARENT_PID=$(get_ppid_macos)
-  check_process_alive() { is_process_alive_macos $1; }
-elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
-  PARENT_PID=$(get_ppid_linux)
-  check_process_alive() { is_process_alive_linux $1; }
-else
-  echo "Unsupported OS"
-  exit 1
-fi
-
-# echo "Parent PID: $PARENT_PID"
-
-# Start anvil in the background.
-RAYON_NUM_THREADS=1 anvil $@ &
-CHILD_PID=$!
-
-cleanup() {
-    kill $CHILD_PID
-}
-
-trap cleanup EXIT
-
-# Continuously check if the parent process is still alive.
-while check_process_alive $PARENT_PID; do
-  sleep 1
-done
diff --git a/yarn-project/ethereum/src/test/start_anvil.ts b/yarn-project/ethereum/src/test/start_anvil.ts
index f5ba8609e15f..49cc1e3d0548 100644
--- a/yarn-project/ethereum/src/test/start_anvil.ts
+++ b/yarn-project/ethereum/src/test/start_anvil.ts
@@ -1,10 +1,11 @@
 import { createLogger } from '@aztec/foundation/log';
 import { makeBackoff, retry } from '@aztec/foundation/retry';
 import type { TestDateProvider } from '@aztec/foundation/timer';
-import { fileURLToPath } from '@aztec/foundation/url';
 
-import { type ChildProcess, spawn } from 'child_process';
-import { dirname, resolve } from 'path';
+import { type ChildProcess, spawn, spawnSync } from 'child_process';
+import { existsSync } from 'fs';
+import { homedir } from 'os';
+import { join } from 'path';
 
 /** Minimal interface matching the @viem/anvil Anvil shape used by callers. */
 export interface Anvil {
@@ -14,6 +15,97 @@ export interface Anvil {
   stop(): Promise<void>;
 }
 
+// Watchdog wrapper: instead of spawning anvil directly, we spawn a small bash supervisor that runs
+// anvil as a background child and polls its own parent (this node process). If the parent dies for
+// ANY reason — including SIGKILL / crash / OOM, where node's own exit handlers never run — the poll
+// loop ends and the EXIT trap reaps anvil. The script is inlined (rather than shipped as a `.sh`) so
+// it works from the published npm tarball too, and the resolved anvil binary is passed via
+// `$ANVIL_BIN` so it works without `anvil` on PATH.
+//
+// `$@` is the anvil argv; `bash -c <script> bash <...args>` puts the args in `$@` and `$0` = 'bash'.
+//
+// The EXIT trap reaps anvil; INT/TERM just `exit` (which fires the EXIT trap) so a signal terminates
+// the supervisor promptly instead of being swallowed — a trapped TERM does NOT terminate the shell,
+// so trapping the kill directly on TERM would leave the poll loop running and the caller's teardown
+// hanging until its SIGKILL escalation. `sleep & wait` makes the poll interruptible, so INT/TERM are
+// handled immediately rather than after the current `sleep` returns.
+const ANVIL_WATCHDOG = `
+set -u
+parent=$PPID
+"$ANVIL_BIN" "$@" &
+anvil_pid=$!
+trap 'kill "$anvil_pid" 2>/dev/null' EXIT
+trap 'exit 0' INT TERM
+while kill -0 "$parent" 2>/dev/null; do sleep 1 & wait $!; done
+`;
+
+/**
+ * Splice the directories where `aztec-up` installs foundry/nargo binaries into `process.env.PATH`.
+ * Idempotent.
+ *
+ * Necessary because `deployAztecL1Contracts` shells out to bare `forge`/`solc`, and those inherit
+ * PATH from us. Since the aztec-up change that stopped polluting the user's interactive PATH,
+ * `forge`/`cast`/`anvil`/`nargo` are only reachable via `~/.aztec/current/internal-bin/`.
+ */
+export function ensureAztecBinsInPath(): void {
+  const dirs = [join(homedir(), '.aztec', 'current', 'internal-bin'), join(homedir(), '.foundry', 'bin')].filter(d =>
+    existsSync(d),
+  );
+
+  if (dirs.length === 0) {
+    return;
+  }
+
+  const sep = process.platform === 'win32' ? ';' : ':';
+  const current = process.env.PATH ?? '';
+  const parts = current.split(sep);
+  const missing = dirs.filter(d => !parts.includes(d));
+  if (missing.length === 0) {
+    return;
+  }
+
+  process.env.PATH = [...missing, ...parts].filter(Boolean).join(sep);
+}
+
+/**
+ * Locate the `anvil` binary. Order:
+ *   1. `$ANVIL_BIN` (explicit override, e.g. for CI with a pinned version).
+ *   2. `~/.aztec/current/internal-bin/anvil` — where aztec-up installs it.
+ *   3. `~/.aztec/current/bin/aztec-anvil` — the publicly-exposed symlink.
+ *   4. `~/.foundry/bin/anvil` — standalone foundryup install.
+ *   5. `which anvil` — anything else on PATH.
+ *
+ * Throws with a directive message if none work.
+ */
+export function resolveAnvilBinary(): string {
+  const envBin = process.env.ANVIL_BIN;
+  if (envBin && existsSync(envBin)) {
+    return envBin;
+  }
+
+  const candidates = [
+    join(homedir(), '.aztec', 'current', 'internal-bin', 'anvil'),
+    join(homedir(), '.aztec', 'current', 'bin', 'aztec-anvil'),
+    join(homedir(), '.foundry', 'bin', 'anvil'),
+  ];
+  for (const path of candidates) {
+    if (existsSync(path)) {
+      return path;
+    }
+  }
+
+  const which = spawnSync('sh', ['-c', 'command -v anvil'], { encoding: 'utf8' });
+  if (which.status === 0 && which.stdout.trim()) {
+    return which.stdout.trim();
+  }
+
+  throw new Error(
+    'anvil binary not found. Tried $ANVIL_BIN, ~/.aztec/current/internal-bin/anvil, ' +
+      '~/.aztec/current/bin/aztec-anvil, ~/.foundry/bin/anvil, and $PATH. ' +
+      'Install via `aztec-up` or set ANVIL_BIN to a working binary.',
+  );
+}
+
 /**
  * Ensures there's a running Anvil instance and returns the RPC URL.
  */
@@ -42,7 +134,8 @@ export async function startAnvil(
     dateProvider?: TestDateProvider;
   } = {},
 ): Promise<{ anvil: Anvil; methodCalls?: string[]; rpcUrl: string; stop: () => Promise<void> }> {
-  const anvilBinary = resolve(dirname(fileURLToPath(import.meta.url)), '../../', 'scripts/anvil_kill_wrapper.sh');
+  ensureAztecBinsInPath();
+  const anvilBinary = resolveAnvilBinary();
   const logger = opts.log ? createLogger('ethereum:anvil') : undefined;
   const methodCalls = opts.captureMethodCalls ? ([] as string[]) : undefined;
 
@@ -50,6 +143,9 @@ export async function startAnvil(
 
   const anvil = await retry(
     async () => {
+      // `--port 0` lets anvil bind an OS-assigned ephemeral port; the actual port is read back from
+      // its "Listening on host:port" stdout below, so independent suites can spawn their own anvil
+      // in parallel without fighting over a fixed port.
       const port = opts.port ?? (process.env.ANVIL_PORT ? parseInt(process.env.ANVIL_PORT) : 8545);
       const args: string[] = [
         '--host',
@@ -71,9 +167,11 @@ export async function startAnvil(
       }
       args.push('--slots-in-an-epoch', String(opts.slotsInAnEpoch ?? 1));
 
-      const child = spawn(anvilBinary, args, {
+      // Spawn the watchdog (see ANVIL_WATCHDOG). It launches anvil with these args and reaps it if we
+      // die; `$0` is 'bash' and `$@` is the anvil argv.
+      const child = spawn('bash', ['-c', ANVIL_WATCHDOG, 'bash', ...args], {
         stdio: ['ignore', 'pipe', 'pipe'],
-        env: { ...process.env, RAYON_NUM_THREADS: '1' },
+        env: { ...process.env, ANVIL_BIN: anvilBinary, RAYON_NUM_THREADS: '1' },
       });
 
       // Wait for "Listening on" or an early exit.
@@ -183,7 +281,10 @@ function syncDateProviderFromAnvilOutput(text: string, dateProvider: TestDatePro
   }
 }
 
-/** Send SIGTERM, wait up to 5 s, then SIGKILL. All timers are always cleared. */
+/**
+ * Send SIGTERM to the watchdog, wait up to 5 s, then SIGKILL. The watchdog's trap forwards the
+ * signal to anvil, so terminating it tears down anvil too. All timers are always cleared.
+ */
 function killChild(child: ChildProcess): Promise<void> {
   return new Promise<void>(resolve => {
     if (child.exitCode !== null || child.killed) {