diff --git a/.github/actions/clone-praxis/action.yml b/.github/actions/clone-praxis/action.yml
new file mode 100644
index 00000000..12f7f3a1
--- /dev/null
+++ b/.github/actions/clone-praxis/action.yml
@@ -0,0 +1,20 @@
+name: Clone Praxis core
+description: >-
+  Clone praxis core repo as a sibling directory so
+  path-based [patch.crates-io] overrides resolve.
+
+inputs:
+  ref:
+    description: "Git ref to checkout (branch, tag, or SHA)"
+    required: false
+    default: "main"
+
+runs:
+  using: composite
+  steps:
+    - name: Clone praxis core
+      run: >-
+        git clone --depth 1 --branch "${{ inputs.ref }}"
+        https://github.com/praxis-proxy/praxis.git
+        "$GITHUB_WORKSPACE/../praxis"
+      shell: bash
diff --git a/.github/actions/patch-praxis/action.yml b/.github/actions/patch-praxis/action.yml
new file mode 100644
index 00000000..63982a18
--- /dev/null
+++ b/.github/actions/patch-praxis/action.yml
@@ -0,0 +1,20 @@
+name: Patch Praxis dependencies
+description: >-
+  Override crates.io praxis dependencies with local
+  path dependencies from the cloned praxis repo.
+
+runs:
+  using: composite
+  steps:
+    - name: Append [patch.crates-io] to Cargo.toml
+      run: |
+        cat >> Cargo.toml << 'PATCH'
+
+        [patch.crates-io]
+        praxis-proxy-core = { path = "../praxis/core" }
+        praxis-proxy-filter = { path = "../praxis/filter" }
+        praxis-proxy-protocol = { path = "../praxis/protocol" }
+        praxis-proxy-tls = { path = "../praxis/tls" }
+        praxis-proxy = { path = "../praxis/server" }
+        PATCH
+      shell: bash
diff --git a/.github/workflows/ci-status.yaml b/.github/workflows/ci-status.yaml
index 91d0085d..25b728bf 100644
--- a/.github/workflows/ci-status.yaml
+++ b/.github/workflows/ci-status.yaml
@@ -42,6 +42,7 @@ jobs:
 
             const excludedChecks = new Set([
               'ci-status',
+              'test-praxis-main',
             ]);
 
             const terminalStatuses = new Set(['completed']);
diff --git a/.github/workflows/integration.yaml b/.github/workflows/integration.yaml
index b5881fc1..b7f58e18 100644
--- a/.github/workflows/integration.yaml
+++ b/.github/workflows/integration.yaml
@@ -9,6 +9,7 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    types: [opened, synchronize, reopened]
   workflow_dispatch:
     inputs:
       debug:
@@ -16,7 +17,6 @@ on:
         required: false
         type: boolean
         default: false
-
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
diff --git a/.github/workflows/praxis-compat.yaml b/.github/workflows/praxis-compat.yaml
new file mode 100644
index 00000000..c1548ff7
--- /dev/null
+++ b/.github/workflows/praxis-compat.yaml
@@ -0,0 +1,79 @@
+name: Tests (praxis main)
+
+# ------------------------------------------------------------------------------
+# Workflow Settings
+# ------------------------------------------------------------------------------
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+    types: [opened, synchronize, reopened, labeled]
+  workflow_dispatch:
+    inputs:
+      praxis_ref:
+        description: "Praxis core git ref to test against"
+        required: false
+        type: string
+        default: "main"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
+permissions: {}
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  # ----------------------------------------------------------------------------
+  # Build + test against praxis core main
+  # ----------------------------------------------------------------------------
+
+  test-praxis-main:
+    runs-on: ubuntu-24.04
+    continue-on-error: ${{ contains(github.event.pull_request.labels.*.name, 'praxis-known-issue') }}
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Clone Praxis core (path dependency)
+        uses: ./.github/actions/clone-praxis
+        with:
+          ref: ${{ inputs.praxis_ref || 'main' }}
+
+      - name: Patch Praxis dependencies
+        uses: ./.github/actions/patch-praxis
+
+      - name: Update lockfile for patched dependencies
+        run: cargo update
+
+      - name: Install stable Rust
+        uses: dtolnay/rust-toolchain@6190aa5fb88a88ee71c12769924bbe63a9ab152e # 1.96.0
+
+      - name: Cache Cargo registry and build artifacts
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+        with:
+          path: |
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            target
+          key: ${{ runner.os }}-rust-1.96.0-praxis-main-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-rust-1.96.0-praxis-main-
+
+      - name: Unit tests
+        run: |
+          cargo test -p praxis-ai-apis --features praxis-main
+          cargo test -p praxis-ai-filters --features praxis-main
+          cargo test -p praxis-ai-proxy --features praxis-main
+
+      - name: Schema tests
+        run: cargo test -p praxis-tests-schema --features praxis-main
+
+      - name: Integration tests
+        run: cargo test -p praxis-tests-integration --features praxis-main
diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 3dff8abd..99e174e3 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -9,6 +9,7 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+    types: [opened, synchronize, reopened]
   merge_group:
     branches: [main]
   workflow_dispatch:
@@ -18,7 +19,6 @@ on:
         required: false
         type: boolean
         default: false
-
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
diff --git a/Makefile b/Makefile
index 4cda22bb..54437144 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,8 @@ endif
 	lint fmt doc audit coverage-check \
 	require-container-engine \
 	container container-run \
-	setup-hooks help
+	setup-hooks help \
+	patch-praxis unpatch-praxis
 
 # -------------------------------------------------------------------
 # All
@@ -105,6 +106,35 @@ coverage-check:
 		exit 1; \
 	fi
 
+# -------------------------------------------------------------------
+# Praxis path override (test against local ../praxis)
+# -------------------------------------------------------------------
+
+patch-praxis:
+	@if [ ! -d "../praxis" ]; then \
+		echo "ERROR: ../praxis not found — clone praxis core as a sibling directory first"; \
+		exit 1; \
+	fi
+	@if grep -q '\[patch\.crates-io\]' Cargo.toml; then \
+		echo "Already patched — run 'make unpatch-praxis' first"; \
+		exit 1; \
+	fi
+	@printf '\n[patch.crates-io]\n\
+	praxis-proxy-core = { path = "../praxis/core" }\n\
+	praxis-proxy-filter = { path = "../praxis/filter" }\n\
+	praxis-proxy-protocol = { path = "../praxis/protocol" }\n\
+	praxis-proxy-tls = { path = "../praxis/tls" }\n\
+	praxis-proxy = { path = "../praxis/server" }\n' >> Cargo.toml
+	@echo "Patched Cargo.toml to use ../praxis path dependencies"
+
+unpatch-praxis:
+	@if ! grep -q '\[patch\.crates-io\]' Cargo.toml; then \
+		echo "Nothing to unpatch"; \
+		exit 0; \
+	fi
+	@sed -i.bak '/^\[patch\.crates-io\]/,$$d' Cargo.toml && rm -f Cargo.toml.bak
+	@echo "Removed [patch.crates-io] from Cargo.toml"
+
 # -------------------------------------------------------------------
 # Dev Setup
 # -------------------------------------------------------------------
@@ -145,3 +175,7 @@ help:
 	@echo "Container:"
 	@echo "  container            build praxis-ai container image"
 	@echo "  container-run        run container in foreground (host network)"
+	@echo ""
+	@echo "Praxis override:"
+	@echo "  patch-praxis         use ../praxis path deps instead of crates.io"
+	@echo "  unpatch-praxis       revert to crates.io praxis deps"
diff --git a/apis/Cargo.toml b/apis/Cargo.toml
index 2838ebf9..1d5ec575 100644
--- a/apis/Cargo.toml
+++ b/apis/Cargo.toml
@@ -14,6 +14,7 @@ name = "praxis_ai_apis"
 [features]
 default = ["store"]
 store = ["dep:sqlx", "dep:dashmap"]
+praxis-main = []
 
 [lints]
 workspace = true
diff --git a/apis/src/lib.rs b/apis/src/lib.rs
index b46eb835..8aa30aa9 100644
--- a/apis/src/lib.rs
+++ b/apis/src/lib.rs
@@ -91,6 +91,12 @@ pub(crate) mod test_utils {
             selected_endpoint_index: None,
             time_source: &praxis_core::time::SystemTimeSource,
             upstream: None,
+            #[cfg(feature = "praxis-main")]
+            peer_identity: None,
+            #[cfg(feature = "praxis-main")]
+            pre_read_mutations: Vec::new(),
+            #[cfg(feature = "praxis-main")]
+            structured_metadata: std::collections::HashMap::new(),
         }
     }
 
diff --git a/filters/Cargo.toml b/filters/Cargo.toml
index 035b7bd7..b3252f1a 100644
--- a/filters/Cargo.toml
+++ b/filters/Cargo.toml
@@ -14,6 +14,7 @@ name = "praxis_ai_filters"
 [features]
 default = ["apis"]
 apis = ["praxis-ai-apis/default"]
+praxis-main = []
 
 [lints]
 workspace = true
diff --git a/filters/src/agentic/a2a/mod.rs b/filters/src/agentic/a2a/mod.rs
index c0f7320b..c420a103 100644
--- a/filters/src/agentic/a2a/mod.rs
+++ b/filters/src/agentic/a2a/mod.rs
@@ -674,15 +674,30 @@ fn clear_sse_capture_metadata(ctx: &mut HttpFilterContext<'_>) {
 fn build_json_rpc_config(max_body_bytes: usize) -> JsonRpcConfig {
     use praxis_filter::builtins::http::payload_processing::json_rpc::config::{BatchPolicy, JsonRpcHeaders};
 
-    JsonRpcConfig {
-        batch_policy: BatchPolicy::Reject,
-        headers: JsonRpcHeaders {
-            id: None,
-            kind: None,
-            method: None,
-        },
-        max_body_bytes,
-        on_invalid: OnInvalidBehavior::Continue,
+    let headers = JsonRpcHeaders {
+        id: None,
+        kind: None,
+        method: None,
+    };
+
+    #[cfg(feature = "praxis-main")]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_batch_size: 100,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
+    }
+    #[cfg(not(feature = "praxis-main"))]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
     }
 }
 
diff --git a/filters/src/agentic/mcp/broker/mod.rs b/filters/src/agentic/mcp/broker/mod.rs
index 787de95e..881b64c5 100644
--- a/filters/src/agentic/mcp/broker/mod.rs
+++ b/filters/src/agentic/mcp/broker/mod.rs
@@ -919,14 +919,29 @@ fn build_json_rpc_config(max_body_bytes: usize) -> JsonRpcConfig {
         json_rpc::config::{BatchPolicy, JsonRpcHeaders},
     };
 
-    JsonRpcConfig {
-        batch_policy: BatchPolicy::Reject,
-        headers: JsonRpcHeaders {
-            id: None,
-            kind: None,
-            method: None,
-        },
-        max_body_bytes,
-        on_invalid: OnInvalidBehavior::Continue,
+    let headers = JsonRpcHeaders {
+        id: None,
+        kind: None,
+        method: None,
+    };
+
+    #[cfg(feature = "praxis-main")]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_batch_size: 100,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
+    }
+    #[cfg(not(feature = "praxis-main"))]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
     }
 }
diff --git a/filters/src/agentic/mcp/mod.rs b/filters/src/agentic/mcp/mod.rs
index 679a19a7..758f4ab0 100644
--- a/filters/src/agentic/mcp/mod.rs
+++ b/filters/src/agentic/mcp/mod.rs
@@ -194,15 +194,30 @@ impl HttpFilter for McpFilter {
 fn build_json_rpc_config(max_body_bytes: usize) -> JsonRpcConfig {
     use praxis_filter::builtins::http::payload_processing::json_rpc::config::{BatchPolicy, JsonRpcHeaders};
 
-    JsonRpcConfig {
-        batch_policy: BatchPolicy::Reject,
-        headers: JsonRpcHeaders {
-            id: None,
-            kind: None,
-            method: None,
-        },
-        max_body_bytes,
-        on_invalid: OnInvalidBehavior::Continue,
+    let headers = JsonRpcHeaders {
+        id: None,
+        kind: None,
+        method: None,
+    };
+
+    #[cfg(feature = "praxis-main")]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_batch_size: 100,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
+    }
+    #[cfg(not(feature = "praxis-main"))]
+    {
+        JsonRpcConfig {
+            batch_policy: BatchPolicy::Reject,
+            headers,
+            max_body_bytes,
+            on_invalid: OnInvalidBehavior::Continue,
+        }
     }
 }
 
diff --git a/filters/src/lib.rs b/filters/src/lib.rs
index db9a7dff..763987bc 100644
--- a/filters/src/lib.rs
+++ b/filters/src/lib.rs
@@ -86,6 +86,12 @@ pub(crate) mod test_utils {
             selected_endpoint_index: None,
             time_source: &praxis_core::time::SystemTimeSource,
             upstream: None,
+            #[cfg(feature = "praxis-main")]
+            peer_identity: None,
+            #[cfg(feature = "praxis-main")]
+            pre_read_mutations: Vec::new(),
+            #[cfg(feature = "praxis-main")]
+            structured_metadata: std::collections::HashMap::new(),
         }
     }
 
diff --git a/server/Cargo.toml b/server/Cargo.toml
index 413de663..e2ab058e 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -17,6 +17,9 @@ path = "src/lib.rs"
 name = "praxis-ai"
 path = "src/main.rs"
 
+[features]
+praxis-main = ["praxis-ai-filters/praxis-main", "praxis-ai-apis/praxis-main"]
+
 [lints]
 workspace = true
 
diff --git a/server/src/pipelines.rs b/server/src/pipelines.rs
index a956a574..2516d428 100644
--- a/server/src/pipelines.rs
+++ b/server/src/pipelines.rs
@@ -97,6 +97,13 @@ fn validate_pipeline(
     skip: bool,
     allow_open_security: bool,
 ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    #[cfg(feature = "praxis-main")]
+    let errors = pipeline.ordering_errors(
+        entries,
+        allow_open_security,
+        &praxis_core::config::SkipPipelineChecks::default(),
+    );
+    #[cfg(not(feature = "praxis-main"))]
     let errors = pipeline.ordering_errors(entries, allow_open_security);
 
     if skip {
diff --git a/tests/integration/Cargo.toml b/tests/integration/Cargo.toml
index 5ddc67f9..a401863c 100644
--- a/tests/integration/Cargo.toml
+++ b/tests/integration/Cargo.toml
@@ -10,6 +10,7 @@ publish = false
 [features]
 cpex-policy-engine = ["praxis-filter/cpex-policy-engine"]
 no-mac-cert-rotation-tests = [] # We use this to disable testing cert rotation on macOS
+praxis-main = ["praxis-test-utils/praxis-main"]
 
 [lints]
 workspace = true
diff --git a/tests/schema/Cargo.toml b/tests/schema/Cargo.toml
index 8089584c..41d41c80 100644
--- a/tests/schema/Cargo.toml
+++ b/tests/schema/Cargo.toml
@@ -7,6 +7,9 @@ license.workspace = true
 readme = "../../README.md"
 publish = false
 
+[features]
+praxis-main = ["praxis-test-utils/praxis-main"]
+
 [lints]
 workspace = true
 
diff --git a/tests/schema/tests/suite/cluster.rs b/tests/schema/tests/suite/cluster.rs
index fff4379c..c7b90b8f 100644
--- a/tests/schema/tests/suite/cluster.rs
+++ b/tests/schema/tests/suite/cluster.rs
@@ -103,6 +103,12 @@ clusters:
       sni: ""
 "#;
     let err = Config::from_yaml(yaml).unwrap_err();
+    #[cfg(feature = "praxis-main")]
+    assert!(
+        err.to_string().contains("sni must be a valid DNS hostname"),
+        "got: {err}"
+    );
+    #[cfg(not(feature = "praxis-main"))]
     assert!(err.to_string().contains("sni is empty"), "got: {err}");
 }
 
@@ -129,6 +135,12 @@ clusters:
 "#
     );
     let err = Config::from_yaml(&yaml).unwrap_err();
+    #[cfg(feature = "praxis-main")]
+    assert!(
+        err.to_string().contains("sni must be a valid DNS hostname"),
+        "got: {err}"
+    );
+    #[cfg(not(feature = "praxis-main"))]
     assert!(err.to_string().contains("exceeds 253 characters"), "got: {err}");
 }
 
@@ -155,6 +167,12 @@ clusters:
 "#
     );
     let err = Config::from_yaml(&yaml).unwrap_err();
+    #[cfg(feature = "praxis-main")]
+    assert!(
+        err.to_string().contains("sni must be a valid DNS hostname"),
+        "got: {err}"
+    );
+    #[cfg(not(feature = "praxis-main"))]
     assert!(err.to_string().contains("invalid label length"), "got: {err}");
 }
 
@@ -177,6 +195,12 @@ clusters:
       sni: "api..example.com"
 "#;
     let err = Config::from_yaml(yaml).unwrap_err();
+    #[cfg(feature = "praxis-main")]
+    assert!(
+        err.to_string().contains("sni must be a valid DNS hostname"),
+        "got: {err}"
+    );
+    #[cfg(not(feature = "praxis-main"))]
     assert!(err.to_string().contains("invalid label length"), "got: {err}");
 }
 
@@ -199,6 +223,12 @@ clusters:
       sni: "api.exam ple.com"
 "#;
     let err = Config::from_yaml(yaml).unwrap_err();
+    #[cfg(feature = "praxis-main")]
+    assert!(
+        err.to_string().contains("sni must be a valid DNS hostname"),
+        "got: {err}"
+    );
+    #[cfg(not(feature = "praxis-main"))]
     assert!(err.to_string().contains("invalid characters"), "got: {err}");
 }
 
diff --git a/tests/utils/Cargo.toml b/tests/utils/Cargo.toml
index 8f69db63..efc91e3c 100644
--- a/tests/utils/Cargo.toml
+++ b/tests/utils/Cargo.toml
@@ -7,6 +7,9 @@ license.workspace = true
 readme = "../../README.md"
 publish = false
 
+[features]
+praxis-main = ["praxis-ai-proxy/praxis-main"]
+
 [lints]
 workspace = true
 
diff --git a/tests/utils/src/net/backend/simple.rs b/tests/utils/src/net/backend/simple.rs
index e73d2339..06de82a2 100644
--- a/tests/utils/src/net/backend/simple.rs
+++ b/tests/utils/src/net/backend/simple.rs
@@ -10,8 +10,7 @@ use std::{
 };
 
 use praxis_core::config::{
-    AdminConfig, BodyLimitsConfig, Cluster, Config, Endpoint, FailureMode, FilterChainConfig, FilterEntry,
-    InsecureOptions, Listener, ProtocolKind, RuntimeConfig,
+    Cluster, Config, Endpoint, FailureMode, FilterChainConfig, FilterEntry, Listener, ProtocolKind,
 };
 
 use super::specialized::{BackendGuard, read_until_headers_complete, spawn_tcp_server, spawn_tcp_server_with_shutdown};
@@ -401,32 +400,36 @@ fn build_static_response_filter(entry: &RoutedEntry) -> FilterEntry {
 }
 
 /// Assemble a [`Config`] from parts.
+///
+/// Uses serde round-trip so new `#[serde(default)]` fields in
+/// upstream praxis-core (e.g. `metrics`) are filled automatically,
+/// keeping this compatible with both crates.io and path deps.
 fn build_config(address: &str, clusters: Vec<Cluster>, filters: Vec<FilterEntry>) -> Config {
-    Config {
-        admin: AdminConfig::default(),
-        body_limits: BodyLimitsConfig::default(),
-        clusters,
-        filter_chains: vec![FilterChainConfig {
-            name: "backend".to_owned(),
-            filters,
-        }],
-        insecure_options: InsecureOptions::default(),
-        listeners: vec![Listener {
-            address: address.to_owned(),
-            cluster: None,
-            downstream_read_timeout_ms: None,
-            filter_chains: vec!["backend".to_owned()],
-            max_connections: None,
-            name: "backend".to_owned(),
-            protocol: ProtocolKind::default(),
-            tcp_session_timeout_ms: None,
-            tcp_max_duration_secs: None,
-            tls: None,
-            upstream: None,
-        }],
-        runtime: RuntimeConfig::default(),
-        shutdown_timeout_secs: 5,
-    }
+    let listener = Listener {
+        address: address.to_owned(),
+        cluster: None,
+        downstream_read_timeout_ms: None,
+        filter_chains: vec!["backend".to_owned()],
+        max_connections: None,
+        name: "backend".to_owned(),
+        protocol: ProtocolKind::default(),
+        tcp_session_timeout_ms: None,
+        tcp_max_duration_secs: None,
+        tls: None,
+        upstream: None,
+    };
+
+    let chain = FilterChainConfig {
+        name: "backend".to_owned(),
+        filters,
+    };
+
+    let mut map = serde_yaml::Mapping::new();
+    map.insert("clusters".into(), serde_yaml::to_value(clusters).unwrap());
+    map.insert("filter_chains".into(), serde_yaml::to_value(vec![chain]).unwrap());
+    map.insert("listeners".into(), serde_yaml::to_value(vec![listener]).unwrap());
+    map.insert("shutdown_timeout_secs".into(), serde_yaml::to_value(5_u64).unwrap());
+    serde_yaml::from_value(serde_yaml::Value::Mapping(map)).unwrap()
 }
 
 /// Build a YAML header mapping with `name` and `value` keys.
diff --git a/xtask/src/echo.rs b/xtask/src/echo.rs
index 450bc289..a5524f37 100644
--- a/xtask/src/echo.rs
+++ b/xtask/src/echo.rs
@@ -4,10 +4,7 @@
 //! `cargo xtask echo` — quick HTTP test server.
 
 use clap::Parser;
-use praxis_core::config::{
-    AdminConfig, BodyLimitsConfig, Config, FailureMode, FilterChainConfig, FilterEntry, InsecureOptions, Listener,
-    ProtocolKind, RuntimeConfig,
-};
+use praxis_core::config::{Config, FailureMode, FilterChainConfig, FilterEntry, Listener, ProtocolKind};
 
 // -----------------------------------------------------------------------------
 // CLI Arguments
@@ -60,19 +57,21 @@ pub(crate) fn run(mut args: Args) {
 /// [`Config`]: praxis_core::config::Config
 fn build_config(args: &Args) -> Config {
     let entry = build_static_response_entry(args);
-    Config {
-        admin: AdminConfig::default(),
-        body_limits: BodyLimitsConfig::default(),
-        clusters: vec![],
-        filter_chains: vec![FilterChainConfig {
-            name: "echo".into(),
-            filters: vec![entry],
-        }],
-        insecure_options: InsecureOptions::default(),
-        listeners: vec![echo_listener(&args.address)],
-        runtime: RuntimeConfig::default(),
-        shutdown_timeout_secs: 30,
-    }
+
+    let chain = FilterChainConfig {
+        name: "echo".into(),
+        filters: vec![entry],
+    };
+
+    let mut map = serde_yaml::Mapping::new();
+    map.insert("clusters".into(), serde_yaml::to_value(Vec::<()>::new()).unwrap());
+    map.insert("filter_chains".into(), serde_yaml::to_value(vec![chain]).unwrap());
+    map.insert(
+        "listeners".into(),
+        serde_yaml::to_value(vec![echo_listener(&args.address)]).unwrap(),
+    );
+    map.insert("shutdown_timeout_secs".into(), serde_yaml::to_value(30_u64).unwrap());
+    serde_yaml::from_value(serde_yaml::Value::Mapping(map)).unwrap()
 }
 
 /// Build the echo listener bound to `address`.