diff --git a/devnets/chainSpec.ts b/devnets/chainSpec.ts
index 37de44d02..3c964624f 100644
--- a/devnets/chainSpec.ts
+++ b/devnets/chainSpec.ts
@@ -8,7 +8,6 @@ export async function createCustomChainSpec(
   customize: (chainSpec: ChainSpec) => void,
 ) {
   await ensureDir(tempDir)
-
   const specResult = await new Deno.Command(binary, {
     args: ["build-spec", "--disable-default-bootnode", "--chain", chain],
   }).output()
@@ -18,21 +17,22 @@ export async function createCustomChainSpec(
   }
   const spec = JSON.parse(new TextDecoder().decode(specResult.stdout))
   customize(spec)
-
   const specPath = path.join(tempDir, `chainspec.json`)
   await Deno.writeTextFile(specPath, JSON.stringify(spec, undefined, 2))
+  return createRawChainSpec(tempDir, binary, specPath)
+}
 
+export async function createRawChainSpec(tempDir: string, binary: string, chain: string) {
+  await ensureDir(tempDir)
   const rawResult = await new Deno.Command(binary, {
-    args: ["build-spec", "--disable-default-bootnode", "--chain", specPath, "--raw"],
+    args: ["build-spec", "--disable-default-bootnode", "--chain", chain, "--raw"],
   }).output()
   if (!rawResult.success) {
     // TODO: improve error message
     throw new Error("build-spec --raw failed")
   }
-
   const rawPath = path.join(tempDir, `chainspec-raw.json`)
   await Deno.writeFile(rawPath, rawResult.stdout)
-
   return rawPath
 }
 
diff --git a/devnets/startNetwork.ts b/devnets/startNetwork.ts
index 8051f5b06..7e82f065b 100644
--- a/devnets/startNetwork.ts
+++ b/devnets/startNetwork.ts
@@ -4,7 +4,12 @@ import { writableStreamFromWriter } from "../deps/std/streams.ts"
 import { getFreePort, portReady } from "../util/port.ts"
 import { resolveBinary } from "./binary.ts"
 import { NetworkConfig } from "./CapiConfig.ts"
-import { createCustomChainSpec, GenesisConfig, getGenesisConfig } from "./chainSpec.ts"
+import {
+  createCustomChainSpec,
+  createRawChainSpec,
+  GenesisConfig,
+  getGenesisConfig,
+} from "./chainSpec.ts"
 import { addDevUsers } from "./devUsers.ts"
 
 export interface Network {
@@ -17,6 +22,51 @@ export interface NetworkChain {
   ports: number[]
 }
 
+export async function startNetworkForMetadata(
+  tempDir: string,
+  config: NetworkConfig,
+  signal: AbortSignal,
+): Promise<Network> {
+  const relayBinary = await resolveBinary(config.binary, signal)
+  const relaySpec = await createRawChainSpec(path.join(tempDir, "relay"), relayBinary, config.chain)
+  const [relay, paras] = await Promise.all([
+    spawnChain(
+      path.join(tempDir, "relay"),
+      relayBinary,
+      relaySpec,
+      1,
+      [],
+      relayBinary,
+      signal,
+    ),
+    Promise.all(
+      Object.entries(config.parachains ?? {}).map(async ([name, config]) => {
+        const binary = await resolveBinary(config.binary, signal)
+        const chain = await spawnChain(
+          path.join(tempDir, name),
+          binary,
+          await createRawChainSpec(path.join(tempDir, name), binary, config.chain),
+          1,
+          [
+            "--",
+            "--execution",
+            "wasm",
+            "--chain",
+            relaySpec,
+          ],
+          relayBinary,
+          signal,
+        )
+        return [name, chain] satisfies Narrow
+      }),
+    ),
+  ])
+  return {
+    relay,
+    paras: Object.fromEntries(paras),
+  }
+}
+
 export async function startNetwork(
   tempDir: string,
   config: NetworkConfig,
diff --git a/devnets/syncConfig.ts b/devnets/syncConfig.ts
index 728843a1f..212cc1f57 100644
--- a/devnets/syncConfig.ts
+++ b/devnets/syncConfig.ts
@@ -8,7 +8,7 @@ import { $codegenSpec, CodegenEntry, CodegenSpec } from "../server/codegenSpec.t
 import { normalizePackageName, withSignal } from "../util/mod.ts"
 import { normalizeTypeName } from "../util/normalize.ts"
 import { CapiConfig } from "./CapiConfig.ts"
-import { startNetwork } from "./startNetwork.ts"
+import { startNetworkForMetadata } from "./startNetwork.ts"
 
 export async function syncConfig(tempDir: string, config: CapiConfig) {
   return withSignal(async (signal) => {
@@ -26,7 +26,7 @@ export async function syncConfig(tempDir: string, config: CapiConfig) {
           })
           return
         }
-        const network = await startNetwork(path.join(tempDir, name), chain, signal)
+        const network = await startNetworkForMetadata(path.join(tempDir, name), chain, signal)
         await Promise.all(
           [
             [undefined, network.relay] as const,