diff --git a/crates/aura-cli/src/main.rs b/crates/aura-cli/src/main.rs
index cb320c5..69ac68f 100644
--- a/crates/aura-cli/src/main.rs
+++ b/crates/aura-cli/src/main.rs
@@ -11,7 +11,7 @@ mod render;
 use aura_core::{Firing, Scalar, ScalarKind, Timestamp};
 use aura_engine::{
     f64_field, summarize, BlueprintNode, Composite, Edge, FlatGraph, Harness,
-    OutField, ParamAlias, Role, RunManifest, RunReport, SourceSpec, SweepFamily, Target,
+    OutField, Role, RunManifest, RunReport, SourceSpec, SweepFamily, Target,
 };
 use aura_registry::{rank_by, Registry};
 use aura_std::{Ema, Exposure, Recorder, SimBroker, Sma, Sub};
@@ -136,7 +136,11 @@ fn run_sample() -> RunReport {
 fn sma_cross(name: &str) -> Composite {
     Composite::new(
         name,
-        vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+        vec![
+            Sma::builder().named("fast").into(), // fast SMA leg
+            Sma::builder().named("slow").into(), // slow SMA leg
+            Sub::builder().into(),
+        ],
         vec![
             Edge { from: 0, to: 2, slot: 0, from_field: 0 },
             Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -146,10 +150,6 @@ fn sma_cross(name: &str) -> Composite {
             targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }],
             source: None,
         }],
-        vec![
-            ParamAlias { name: "fast".into(), node: 0, slot: 0 }, // fast SMA length
-            ParamAlias { name: "slow".into(), node: 1, slot: 0 }, // slow SMA length
-        ],
         vec![OutField { node: 2, field: 0, name: "cross".into() }],
     )
 }
@@ -190,7 +190,6 @@ fn sample_blueprint_with_sinks() -> (
             ],
             source: Some(ScalarKind::F64),
         }],
-        vec![], // params: the interior sma_cross carries the aliases
         vec![], // output: the root ends in sinks, no re-export
     );
     (bp, rx_eq, rx_ex)
@@ -226,9 +225,9 @@ fn scalar_as_param_f64(s: &Scalar) -> f64 {
 fn sweep_family() -> SweepFamily {
     let bp = sample_blueprint_with_sinks().0;
     let space = bp.param_space();
-    bp.axis("sma_cross.fast", [2, 3])
-        .axis("sma_cross.slow", [4, 5])
-        .axis("scale", [0.5])
+    bp.axis("sma_cross.fast.length", [2, 3])
+        .axis("sma_cross.slow.length", [4, 5])
+        .axis("exposure.scale", [0.5])
         .sweep(|point| {
             let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks();
             let mut h = bp
@@ -338,11 +337,11 @@ fn macd(name: &str) -> Composite {
     Composite::new(
         name,
         vec![
-            Ema::builder().into(), // 0 fast EMA
-            Ema::builder().into(), // 1 slow EMA
-            Sub::builder().into(), // 2 MACD line = fast − slow
-            Ema::builder().into(), // 3 signal EMA of the MACD line
-            Sub::builder().into(), // 4 histogram = MACD line − signal
+            Ema::builder().named("fast").into(),   // 0 fast EMA
+            Ema::builder().named("slow").into(),   // 1 slow EMA
+            Sub::builder().into(),                 // 2 MACD line = fast − slow
+            Ema::builder().named("signal").into(), // 3 signal EMA of the MACD line
+            Sub::builder().into(),                 // 4 histogram = MACD line − signal
         ],
         vec![
             Edge { from: 0, to: 2, slot: 0, from_field: 0 }, // fast   → line[0]
@@ -359,11 +358,6 @@ fn macd(name: &str) -> Composite {
             ],
             source: None,
         }],
-        vec![
-            ParamAlias { name: "fast".into(), node: 0, slot: 0 },   // fast EMA length
-            ParamAlias { name: "slow".into(), node: 1, slot: 0 },   // slow EMA length
-            ParamAlias { name: "signal".into(), node: 3, slot: 0 }, // signal EMA length
-        ],
         vec![
             OutField { node: 2, field: 0, name: "macd".into() },      // the MACD line
             OutField { node: 3, field: 0, name: "signal".into() },    // the signal line
@@ -402,7 +396,6 @@ fn macd_strategy_blueprint(
             ],
             source: Some(ScalarKind::F64),
         }],
-        vec![], // params: the interior macd carries the aliases
         vec![], // output: the root ends in sinks, no re-export
     )
 }
@@ -513,9 +506,9 @@ mod tests {
         // so a caller can bootstrap one point, run it, and drain both sinks.
         let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks();
         let mut h = bp
-            .with("sma_cross.fast", 2)
-            .with("sma_cross.slow", 4)
-            .with("scale", 0.5)
+            .with("sma_cross.fast.length", 2)
+            .with("sma_cross.slow.length", 4)
+            .with("exposure.scale", 0.5)
             .bootstrap()
             .expect("sample blueprint compiles under a valid point");
         h.run(vec![synthetic_prices()]);
@@ -534,10 +527,10 @@ mod tests {
         for line in &lines {
             assert!(line.starts_with(r#"{"manifest":{"commit":""#), "not a RunReport: {line}");
         }
-        assert!(lines[0].contains(r#""params":{"sma_cross.fast":2,"sma_cross.slow":4,"scale":0.5}"#), "line0: {}", lines[0]);
-        assert!(lines[1].contains(r#""params":{"sma_cross.fast":2,"sma_cross.slow":5,"scale":0.5}"#), "line1: {}", lines[1]);
-        assert!(lines[2].contains(r#""params":{"sma_cross.fast":3,"sma_cross.slow":4,"scale":0.5}"#), "line2: {}", lines[2]);
-        assert!(lines[3].contains(r#""params":{"sma_cross.fast":3,"sma_cross.slow":5,"scale":0.5}"#), "line3: {}", lines[3]);
+        assert!(lines[0].contains(r#""params":{"sma_cross.fast.length":2,"sma_cross.slow.length":4,"exposure.scale":0.5}"#), "line0: {}", lines[0]);
+        assert!(lines[1].contains(r#""params":{"sma_cross.fast.length":2,"sma_cross.slow.length":5,"exposure.scale":0.5}"#), "line1: {}", lines[1]);
+        assert!(lines[2].contains(r#""params":{"sma_cross.fast.length":3,"sma_cross.slow.length":4,"exposure.scale":0.5}"#), "line2: {}", lines[2]);
+        assert!(lines[3].contains(r#""params":{"sma_cross.fast.length":3,"sma_cross.slow.length":5,"exposure.scale":0.5}"#), "line3: {}", lines[3]);
         for line in &lines {
             assert!(line.contains(r#""total_pips":"#), "missing total_pips: {line}");
             assert!(line.contains(r#""max_drawdown":"#), "missing max_drawdown: {line}");
@@ -577,24 +570,25 @@ mod tests {
     }
 
     /// E2E acceptance (#41 / spec 0019, the worked example): the real MACD strategy
-    /// blueprint's swept param surface relabels the three otherwise-indistinguishable
-    /// EMA `length` slots to `macd.fast` / `macd.slow` / `macd.signal` — the named
-    /// composite boundary visible end-to-end through `param_space()`, with the slot
-    /// count and order unchanged (C23 — pure naming overlay, not curation: every
-    /// interior slot stays sweepable, the `scale` knob is unaffected).
+    /// blueprint's swept param surface qualifies the three otherwise-indistinguishable
+    /// EMA `length` slots by node name to `macd.fast.length` / `macd.slow.length` /
+    /// `macd.signal.length` — the named composite boundary visible end-to-end through
+    /// `param_space()`, with the slot count and order unchanged (C23 — node names are
+    /// non-load-bearing: every interior slot stays sweepable, the `exposure.scale`
+    /// knob is unaffected).
     #[test]
-    fn macd_param_space_surfaces_the_three_named_aliases() {
+    fn macd_param_space_surfaces_the_three_named_legs() {
         let names: Vec<String> =
             macd_blueprint().param_space().into_iter().map(|p| p.name).collect();
-        // three aliased composite slots, in declared (fast, slow, signal) order,
-        // then the strategy-level Exposure `scale` (outside the composite, unaliased).
+        // three named composite-interior slots, in declared (fast, slow, signal)
+        // order, then the strategy-level Exposure `scale` (a root-level leaf).
         assert_eq!(
             names,
             vec![
-                "macd.fast".to_string(),
-                "macd.slow".to_string(),
-                "macd.signal".to_string(),
-                "scale".to_string(),
+                "macd.fast.length".to_string(),
+                "macd.slow.length".to_string(),
+                "macd.signal.length".to_string(),
+                "exposure.scale".to_string(),
             ],
             "MACD param surface must expose the three named EMA lengths + scale",
         );
diff --git a/crates/aura-cli/tests/cli_run.rs b/crates/aura-cli/tests/cli_run.rs
index 5f72a51..54ccf65 100644
--- a/crates/aura-cli/tests/cli_run.rs
+++ b/crates/aura-cli/tests/cli_run.rs
@@ -211,7 +211,7 @@ fn sweep_prints_four_json_lines_and_exits_zero() {
     // pin the first odometer point's manifest params, not the commit value.
     assert!(first.starts_with("{\"manifest\":{\"commit\":\""), "got: {stdout}");
     assert!(
-        first.contains("\"params\":{\"sma_cross.fast\":2,\"sma_cross.slow\":4,\"scale\":0.5}"),
+        first.contains("\"params\":{\"sma_cross.fast.length\":2,\"sma_cross.slow.length\":4,\"exposure.scale\":0.5}"),
         "got: {stdout}"
     );
     let _ = std::fs::remove_dir_all(&cwd);
diff --git a/crates/aura-core/src/node.rs b/crates/aura-core/src/node.rs
index 6caae98..b53e814 100644
--- a/crates/aura-core/src/node.rs
+++ b/crates/aura-core/src/node.rs
@@ -76,6 +76,7 @@ pub struct ParamSpec {
 /// pre-build (#43).
 pub struct PrimitiveBuilder {
     name: &'static str,
+    instance_name: Option<String>,
     schema: NodeSchema,
     // The build closure's type is exactly the recipe contract (a param slice in, a
     // boxed node out); a type alias would not clarify it.
@@ -92,7 +93,20 @@ impl PrimitiveBuilder {
         schema: NodeSchema,
         build: impl Fn(&[Scalar]) -> Box<dyn Node> + 'static,
     ) -> Self {
-        Self { name, schema, build: Box::new(build) }
+        Self { name, instance_name: None, schema, build: Box::new(build) }
+    }
+    /// Set this node instance's name. Must be non-empty.
+    pub fn named(mut self, name: &str) -> Self {
+        debug_assert!(!name.is_empty(), "node name must be non-empty");
+        self.instance_name = Some(name.to_string());
+        self
+    }
+    /// The resolved node name: the explicit instance name if set, else the
+    /// type label ASCII-lowercased verbatim (e.g. "SimBroker" -> "simbroker").
+    pub fn node_name(&self) -> String {
+        self.instance_name
+            .clone()
+            .unwrap_or_else(|| self.name.to_ascii_lowercase())
     }
     /// The full declared signature (read pre-build by `Composite::param_space`,
     /// `BlueprintNode::signature`, and the renderer).
@@ -120,7 +134,7 @@ impl PrimitiveBuilder {
 /// case), and an **empty** `output` (`vec![]`) declares a **pure consumer**
 /// (sink role, C8) — a node with no output port. Built once at wiring, never on
 /// the hot path — the `Vec`s are fine here.
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct NodeSchema {
     pub inputs: Vec<PortSpec>,
     pub output: Vec<FieldSpec>,
@@ -215,6 +229,26 @@ mod tests {
         assert_eq!(none.label(), "Sub");
     }
 
+    #[test]
+    fn node_name_defaults_to_lowercased_type_label() {
+        // unnamed → the type label, ASCII-lowercased verbatim (no snake_case)
+        let unnamed = PrimitiveBuilder::new(
+            "SimBroker",
+            NodeSchema::default(),
+            |_| panic!("not built in this test"),
+        );
+        assert_eq!(unnamed.node_name(), "simbroker");
+
+        // explicit name overrides
+        let named = PrimitiveBuilder::new(
+            "SMA",
+            NodeSchema::default(),
+            |_| panic!("not built in this test"),
+        )
+        .named("fast");
+        assert_eq!(named.node_name(), "fast");
+    }
+
     #[test]
     fn primitive_builder_build_runs_the_closure() {
         let f = PrimitiveBuilder::new(
diff --git a/crates/aura-engine/src/blueprint.rs b/crates/aura-engine/src/blueprint.rs
index a34fccc..f24cc2f 100644
--- a/crates/aura-engine/src/blueprint.rs
+++ b/crates/aura-engine/src/blueprint.rs
@@ -87,7 +87,7 @@ fn derive_signature(c: &Composite) -> NodeSchema {
         })
         .collect();
     let mut params = Vec::new();
-    collect_params(c.nodes(), "", c.params(), &mut params);
+    collect_params(c.nodes(), "", &mut params);
     NodeSchema { inputs, output, params }
 }
 
@@ -118,17 +118,6 @@ pub struct Role {
     pub source: Option<ScalarKind>,
 }
 
-/// A composite-level alias relabelling one interior leaf param slot's surface
-/// name in `param_space()`. `node` is the interior item index, `slot` the param
-/// slot within that leaf. Pure legibility: the alias relabels in place and never
-/// reorders, adds, or removes a slot (C23 — identity stays the slot).
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct ParamAlias {
-    pub name: String,
-    pub node: usize,
-    pub slot: usize,
-}
-
 /// A reusable sub-graph fragment compiled away by inlining (C9/C23). It is **not**
 /// a [`Node`]: it is never `eval`'d. It holds interior items (local indices),
 /// interior edges (local indices), input roles (role `r` fans into the interior
@@ -139,7 +128,6 @@ pub struct Composite {
     nodes: Vec<BlueprintNode>,
     edges: Vec<Edge>,
     input_roles: Vec<Role>,
-    params: Vec<ParamAlias>,
     output: Vec<OutField>,
 }
 
@@ -153,10 +141,9 @@ impl Composite {
         nodes: Vec<BlueprintNode>,
         edges: Vec<Edge>,
         input_roles: Vec<Role>,
-        params: Vec<ParamAlias>,
         output: Vec<OutField>,
     ) -> Self {
-        Self { name: name.into(), nodes, edges, input_roles, params, output }
+        Self { name: name.into(), nodes, edges, input_roles, output }
     }
 
     /// The authored render name (cluster title, #13). Non-load-bearing.
@@ -177,11 +164,6 @@ impl Composite {
     pub fn input_roles(&self) -> &[Role] {
         &self.input_roles
     }
-    /// The param aliases: each relabels one interior leaf param slot's surface
-    /// name in `param_space()` (pure naming overlay; identity stays the slot, C23).
-    pub fn params(&self) -> &[ParamAlias] {
-        &self.params
-    }
     /// The exposed output record: each entry re-exports one interior
     /// `(node, output-field)` under a boundary name (C8 — one port, K columns).
     pub fn output(&self) -> &[OutField] {
@@ -189,12 +171,14 @@ impl Composite {
     }
 
     /// The aggregated, flat, path-qualified param-space (C12): every node's declared
-    /// params, concatenated in lowering order. The ROOT uses an empty path prefix
-    /// (its own name does not prefix — preserving the pre-refactor param names);
-    /// interior composite names prefix via the recursion in `collect_params`.
+    /// params, concatenated in lowering order. Each param is `<node>.<param>` (the
+    /// node name = its instance name, default = lowercased type label), with the
+    /// composite path prefixed at every level including the root — so a top-level
+    /// leaf carries its own node segment (e.g. `sma.length`). Interior composite
+    /// names prefix via the recursion in `collect_params`.
     pub fn param_space(&self) -> Vec<ParamSpec> {
         let mut out = Vec::new();
-        collect_params(&self.nodes, "", &self.params, &mut out);
+        collect_params(&self.nodes, "", &mut out);
         out
     }
 
@@ -269,8 +253,9 @@ impl Composite {
 
     /// Begin binding this blueprint's knobs **by name** for a single run (the
     /// fluent alternative to a positional `bootstrap_with_params` vector). The
-    /// bound name is the exact `param_space()` name — path-qualified for a knob
-    /// inside a composite (`sma_cross.fast`), bare for a root-level knob (`scale`).
+    /// bound name is the exact `param_space()` name — `<node>.<param>` at every
+    /// level, e.g. `sma_cross.fast.length` for a composite-interior knob and
+    /// `exposure.scale` for a root-level knob.
     pub fn with(self, name: &str, v: impl Into<Scalar>) -> Binder {
         Binder { bp: self, bound: vec![(name.to_string(), v.into())] }
     }
@@ -536,81 +521,37 @@ fn validate_wiring(
     Ok(())
 }
 
-/// The recursive authoring signature of interior node `node`: the type initial,
-/// then one initial per declared param alias (declared order), then each wired
-/// input's signature in slot order — recursing into interior-leaf sources,
-/// stopping at a named source (role name / nested-composite name). Single source
-/// of truth for the fan-in distinguishability check (collision = equal
-/// signatures) and the CLI render (shortest sibling-unique prefix). Terminates:
-/// the dataflow is a DAG (C5) and the descent stops at named ports.
-pub fn signature_of(
-    nodes: &[BlueprintNode],
-    edges: &[Edge],
-    roles: &[Role],
-    aliases: &[ParamAlias],
-    node: usize,
-) -> String {
-    let mut s = String::new();
+/// The recursive authoring signature of interior node `node`: the node name (the
+/// instance name, default = the lowercased type label), then each wired input's
+/// signature in slot order — recursing into interior-leaf sources, stopping at a
+/// named source (role name / nested-composite name). Single source of truth for
+/// the fan-in distinguishability check (collision = equal signatures) and the CLI
+/// render (shortest sibling-unique prefix). Terminates: the dataflow is a DAG (C5)
+/// and the descent stops at named ports.
+pub fn signature_of(nodes: &[BlueprintNode], edges: &[Edge], roles: &[Role], node: usize) -> String {
     match &nodes[node] {
+        // a nested composite is a named source: its name, no descent.
+        BlueprintNode::Composite(inner) => inner.name().to_string(),
         BlueprintNode::Primitive(f) => {
-            if let Some(ch) = f.label().chars().next() {
-                s.push(ch);
-            }
-            for a in aliases_on(aliases, node) {
-                if let Some(ch) = a.name.chars().next() {
-                    s.push(ch);
-                }
-            }
+            let mut s = f.node_name();
             // wired input slots in slot order; per slot, the source's signature
-            // (interior edge -> recurse; role -> the role initial, no descent)
+            // (interior edge -> recurse; role -> the role name, no descent)
             let mut slotted: Vec<(usize, String)> = Vec::new();
             for e in edges.iter().filter(|e| e.to == node) {
-                slotted.push((e.slot, signature_of(nodes, edges, roles, aliases, e.from)));
+                slotted.push((e.slot, signature_of(nodes, edges, roles, e.from)));
             }
             for r in roles {
                 for t in r.targets.iter().filter(|t| t.node == node) {
-                    // a role is a named source: it contributes its initial, no
-                    // descent (matching the nested-composite branch below).
-                    let init = r.name.chars().next().map(String::from).unwrap_or_default();
-                    slotted.push((t.slot, init));
+                    slotted.push((t.slot, r.name.clone()));
                 }
             }
             slotted.sort_by_key(|(slot, _)| *slot);
             for (_, sig) in slotted {
                 s.push_str(&sig);
             }
-        }
-        BlueprintNode::Composite(inner) => {
-            if let Some(ch) = inner.name().chars().next() {
-                s.push(ch);
-            }
+            s
         }
     }
-    s
-}
-
-/// The param aliases declared on interior node `node`, in declared order. The single
-/// anchor for the `a.node == node` predicate shared by the signature base, the
-/// unaliased-param test, and the CLI's render base-length (issue #45) — change the
-/// predicate here, not in three places.
-pub fn aliases_on(aliases: &[ParamAlias], node: usize) -> impl Iterator<Item = &ParamAlias> {
-    aliases.iter().filter(move |a| a.node == node)
-}
-
-/// Validate that every param alias names a real interior leaf param slot: a dangling
-/// `(node, slot)` is a `BadInteriorIndex` (C23 — names are cosmetic, but a dangling
-/// handle is an author error). Sole owner of the alias-index check: the structural
-/// pre-pass recurses every composite that lowering reaches, so `inline_composite`
-/// trusts this has already run rather than re-checking (issue #45).
-fn check_alias_indices(nodes: &[BlueprintNode], aliases: &[ParamAlias]) -> Result<(), CompileError> {
-    for a in aliases {
-        let ok = a.node < nodes.len()
-            && matches!(&nodes[a.node], BlueprintNode::Primitive(f) if a.slot < f.params().len());
-        if !ok {
-            return Err(CompileError::BadInteriorIndex);
-        }
-    }
-    Ok(())
 }
 
 /// Structural validation (param-value-independent): walk every composite in the
@@ -620,7 +561,7 @@ fn check_alias_indices(nodes: &[BlueprintNode], aliases: &[ParamAlias]) -> Resul
 fn check_fan_in_distinguishability(items: &[BlueprintNode]) -> Result<(), CompileError> {
     for item in items {
         if let BlueprintNode::Composite(c) = item {
-            check_composite_fan_in(c.nodes(), c.edges(), c.input_roles(), c.params())?;
+            check_composite_fan_in(c.nodes(), c.edges(), c.input_roles())?;
             check_fan_in_distinguishability(c.nodes())?;
         }
     }
@@ -629,27 +570,22 @@ fn check_fan_in_distinguishability(items: &[BlueprintNode]) -> Result<(), Compil
 
 /// The per-composite fan-in distinguishability check on the destructured pieces:
 /// for each interior node with >1 wired input slot, a collision (equal source
-/// signatures) is a fault only when at least one colliding source has an unaliased
-/// param slot — the unnamed configuration axis. A role contributes its name and
-/// has no param of its own.
+/// signatures, now keyed on the node name) is a fault only when at least one
+/// colliding source carries a param — the unnamed configuration axis resolved by
+/// giving the colliding nodes distinct names. A role contributes its name and has
+/// no param of its own.
 fn check_composite_fan_in(
     nodes: &[BlueprintNode],
     edges: &[Edge],
     input_roles: &[Role],
-    param_aliases: &[ParamAlias],
 ) -> Result<(), CompileError> {
-    // alias-validity first: a bogus alias index is a `BadInteriorIndex`, ordered
-    // ahead of the fan-in fault so a bad alias surfaces as the index error, not as an
-    // incidental collision.
-    check_alias_indices(nodes, param_aliases)?;
-
     for node in 0..nodes.len() {
-        let mut sources: Vec<(usize, String, bool)> = Vec::new(); // (slot, sig, has_unaliased_param)
+        let mut sources: Vec<(usize, String, bool)> = Vec::new(); // (slot, sig, has_param)
         for e in edges.iter().filter(|e| e.to == node) {
             sources.push((
                 e.slot,
-                signature_of(nodes, edges, input_roles, param_aliases, e.from),
-                leaf_has_unaliased_param(nodes, param_aliases, e.from),
+                signature_of(nodes, edges, input_roles, e.from),
+                leaf_has_param(nodes, e.from),
             ));
         }
         for r in input_roles {
@@ -671,50 +607,30 @@ fn check_composite_fan_in(
     Ok(())
 }
 
-/// Whether interior leaf `node` has at least one param slot with no alias in
-/// `aliases` — the unnamed configuration axis the fan-in rule keys on. A non-leaf
-/// (nested composite) reports `false`.
-fn leaf_has_unaliased_param(nodes: &[BlueprintNode], aliases: &[ParamAlias], node: usize) -> bool {
-    match &nodes[node] {
-        BlueprintNode::Primitive(f) => {
-            let n_params = f.params().len();
-            let aliased = aliases_on(aliases, node).count();
-            n_params > aliased
-        }
-        BlueprintNode::Composite(_) => false,
-    }
+/// Whether interior leaf `node` has at least one param slot — the configuration
+/// axis the fan-in rule keys on once the node name no longer distinguishes the
+/// colliding sources. A non-leaf (nested composite) reports `false`.
+fn leaf_has_param(nodes: &[BlueprintNode], node: usize) -> bool {
+    matches!(&nodes[node], BlueprintNode::Primitive(b) if !b.params().is_empty())
 }
 
 /// Recursive read-only walk for `Blueprint::param_space`: a leaf contributes its
-/// declared params under the running path prefix; a composite pushes its `name()`
-/// onto the path and recurses, passing its own param aliases down. A leaf param
-/// slot matched by an `(node, slot)` alias is relabelled in place (C23 — pure
-/// naming overlay; the slot stays, order is untouched). Order mirrors `lower_items`
-/// (items in declared order, composites depth-first) so a param's slot matches the
-/// later flat-node order.
-fn collect_params(
-    items: &[BlueprintNode],
-    prefix: &str,
-    aliases: &[ParamAlias],
-    out: &mut Vec<ParamSpec>,
-) {
-    for (i, item) in items.iter().enumerate() {
+/// declared params under `<prefix>.<node-name>.<param>` (the node name is the
+/// instance name, default = the lowercased type label); a composite pushes its
+/// `name()` onto the path and recurses. Order mirrors `lower_items` (items in
+/// declared order, composites depth-first) so a param's slot matches the later
+/// flat-node order.
+fn collect_params(items: &[BlueprintNode], prefix: &str, out: &mut Vec<ParamSpec>) {
+    for item in items {
         match item {
-            BlueprintNode::Primitive(builder) => {
-                for (s, p) in builder.params().iter().enumerate() {
-                    // an alias for this exact (node, slot) relabels in place;
-                    // otherwise the factory param name, as today.
-                    let local = aliases
-                        .iter()
-                        .find(|a| a.node == i && a.slot == s)
-                        .map(|a| a.name.as_str())
-                        .unwrap_or(p.name.as_str());
-                    let name = if prefix.is_empty() {
-                        local.to_string()
-                    } else {
-                        format!("{prefix}.{local}")
-                    };
-                    out.push(ParamSpec { name, kind: p.kind });
+            BlueprintNode::Primitive(b) => {
+                let node = if prefix.is_empty() {
+                    b.node_name()
+                } else {
+                    format!("{prefix}.{}", b.node_name())
+                };
+                for p in b.params() {
+                    out.push(ParamSpec { name: format!("{node}.{}", p.name), kind: p.kind });
                 }
             }
             BlueprintNode::Composite(c) => {
@@ -723,7 +639,7 @@ fn collect_params(
                 } else {
                     format!("{prefix}.{}", c.name())
                 };
-                collect_params(c.nodes(), &child, c.params(), out);
+                collect_params(c.nodes(), &child, out);
             }
         }
     }
@@ -800,16 +716,13 @@ fn inline_composite(
 ) -> Result<ItemLowering, CompileError> {
     // `name` is the non-load-bearing render symbol (#13); it dissolves at inline
     // (C23 — the boundary does not reach the compilat), so it is not destructured.
-    // `params` (the composite's ParamAlias overlay) is a pure naming layer validated
-    // by the pre-pass and unused in lowering — the injected scalar `params: &[Scalar]`
-    // arg drives `lower_items` below — so it is dropped here.
-    let Composite { name: _, nodes, edges, input_roles, params: _, output } = c;
+    // Node names join the same non-load-bearing debug-symbol class: they qualify the
+    // param-space path at construction but are dropped at lowering — the injected
+    // scalar `params: &[Scalar]` arg drives `lower_items` below; the compilat stays
+    // wired by raw index.
+    let Composite { name: _, nodes, edges, input_roles, output } = c;
     let item_count = nodes.len();
 
-    // alias-validity (a dangling `(node, slot)` is a `BadInteriorIndex`) is owned by
-    // the structural pre-pass `check_alias_indices`, which `compile_with_params` runs
-    // over every composite before any lowering — so it has already fired here (#45).
-
     // recursively lower interior items, then rewrite interior edges through them
     let interior = lower_items(nodes, params, cursor, flat_nodes, flat_signatures, flat_edges)?;
     for e in &edges {
@@ -989,14 +902,14 @@ mod tests {
         // must not be invoked.
         let (bp, _eq, _ex) = composite_sma_cross_harness();
         let result = bp
-            .axis("sma_cross.fast", [2.0, 3.0]) // F64 values for the I64 slot
-            .axis("sma_cross.slow", [4])
-            .axis("scale", [0.5])
+            .axis("sma_cross.fast.length", [2.0, 3.0]) // F64 values for the I64 slot
+            .axis("sma_cross.slow.length", [4])
+            .axis("exposure.scale", [0.5])
             .sweep(|_: &[Scalar]| -> RunReport { panic!("axis pre-validation must reject before running") });
         assert_eq!(
             result,
             Err(BindError::KindMismatch {
-                knob: "sma_cross.fast".to_string(),
+                knob: "sma_cross.fast.length".to_string(),
                 expected: ScalarKind::I64,
                 got: ScalarKind::F64,
             }),
@@ -1011,9 +924,9 @@ mod tests {
         let named = resolve_axes(
             &space,
             &[
-                ("sma_cross.fast".to_string(), vec![Scalar::I64(2), Scalar::I64(3)]),
-                ("sma_cross.slow".to_string(), vec![Scalar::I64(4), Scalar::I64(5)]),
-                ("scale".to_string(), vec![Scalar::F64(0.5)]),
+                ("sma_cross.fast.length".to_string(), vec![Scalar::I64(2), Scalar::I64(3)]),
+                ("sma_cross.slow.length".to_string(), vec![Scalar::I64(4), Scalar::I64(5)]),
+                ("exposure.scale".to_string(), vec![Scalar::F64(0.5)]),
             ],
         )
         .expect("named axes resolve");
@@ -1133,9 +1046,9 @@ mod tests {
         // the positional vector, over the sample composite harness.
         let (bp, comp_eq, comp_ex) = composite_sma_cross_harness();
         let mut named = bp
-            .with("sma_cross.fast", 2)
-            .with("sma_cross.slow", 4)
-            .with("scale", 0.5)
+            .with("sma_cross.fast.length", 2)
+            .with("sma_cross.slow.length", 4)
+            .with("exposure.scale", 0.5)
             .bootstrap()
             .expect("named binding resolves and bootstraps");
         named.run(vec![synthetic_prices()]);
@@ -1280,27 +1193,99 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         )
     }
 
-    #[test]
-    fn signature_of_is_type_initial_plus_aliases_plus_recursive_inputs() {
-        // EMA(fast) fed by role price -> "E" + "f"(alias) + "p"(role, no descent)
-        let c = macd_like_signature_fixture(); // built below
-        let sig = |n| signature_of(c.nodes(), c.edges(), c.input_roles(), c.params(), n);
-        // node 0 = Ema aliased "fast", fed by role "price"
-        assert_eq!(sig(0), "Efp");
-        // node 2 = Sub(node0, node1) where node1 = Ema aliased "slow" -> "S"+inputs
-        assert_eq!(sig(2), "SEfpEsp");
+    /// The SMA-cross signal as a composite under the boundary name `sma_cross`,
+    /// with its two SMA legs given `name` (or left default when `named` is false).
+    /// Nested under a root so the composite name qualifies the param-space path and
+    /// the fan-in check (which inspects nested composites) reaches the Sub fan-in.
+    fn sma_cross_under_root(named: bool) -> Composite {
+        use aura_std::{Sma, Sub};
+        let (a, b) = if named {
+            (Sma::builder().named("fast"), Sma::builder().named("slow"))
+        } else {
+            (Sma::builder(), Sma::builder())
+        };
+        let cross = Composite::new(
+            "sma_cross",
+            vec![a.into(), b.into(), Sub::builder().into()],
+            vec![
+                Edge { from: 0, to: 2, slot: 0, from_field: 0 },
+                Edge { from: 1, to: 2, slot: 1, from_field: 0 },
+            ],
+            vec![Role {
+                name: "price".into(),
+                targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }],
+                source: None,
+            }],
+            vec![OutField { node: 2, field: 0, name: "cross".into() }],
+        );
+        Composite::new(
+            "root",
+            vec![BlueprintNode::Composite(cross)],
+            vec![],
+            vec![Role {
+                name: "src".into(),
+                targets: vec![Target { node: 0, slot: 0 }],
+                source: Some(ScalarKind::F64),
+            }],
+            vec![],
+        )
     }
 
-    /// A composite: two aliased EMAs (fast, slow) on role `price`, into a Sub.
+    #[test]
+    fn named_siblings_path_qualify_with_node_segment() {
+        // two SMAs named fast/slow under composite "sma_cross" -> the node segment
+        // qualifies each leaf's param path under the composite name.
+        let bp = sma_cross_under_root(true);
+        let names: Vec<String> = bp.param_space().into_iter().map(|p| p.name).collect();
+        assert_eq!(names, ["sma_cross.fast.length", "sma_cross.slow.length"]);
+    }
+
+    #[test]
+    fn unnamed_single_primitive_uses_lowercased_type_label_segment() {
+        use aura_std::Sma;
+        let bp = Composite::new("root", vec![Sma::builder().into()], vec![], vec![], vec![]);
+        assert_eq!(bp.param_space()[0].name, "sma.length");
+    }
+
+    #[test]
+    fn unnamed_same_type_param_bearing_fan_in_is_rejected() {
+        // both SMAs default to "sma" -> collide -> fan-in indistinguishable
+        let bp = sma_cross_under_root(false);
+        assert_eq!(bp.compile().err(), Some(CompileError::IndistinguishableFanIn { node: 2 }));
+    }
+
+    #[test]
+    fn named_param_bearing_fan_in_bootstraps() {
+        // distinct node names -> fan-in distinguishable -> compiles (the two SMA
+        // length params are supplied so the only thing under test is the fan-in)
+        let bp = sma_cross_under_root(true);
+        assert!(bp.compile_with_params(&[Scalar::I64(2), Scalar::I64(4)]).is_ok());
+    }
+
+    #[test]
+    fn signature_of_is_node_name_plus_recursive_inputs() {
+        // EMA named "fast" fed by role price -> "fast" + "price" (role, no descent)
+        let c = macd_like_signature_fixture(); // built below
+        let sig = |n| signature_of(c.nodes(), c.edges(), c.input_roles(), n);
+        // node 0 = EMA named "fast", fed by role "price"
+        assert_eq!(sig(0), "fastprice");
+        // node 2 = Sub (default name "sub") over node0/node1; node1 = EMA "slow"
+        assert_eq!(sig(2), "subfastpriceslowprice");
+    }
+
+    /// A composite: two named EMAs (fast, slow) on role `price`, into a Sub.
     fn macd_like_signature_fixture() -> Composite {
         Composite::new(
             "sig",
-            vec![Ema::builder().into(), Ema::builder().into(), Sub::builder().into()],
+            vec![
+                Ema::builder().named("fast").into(),
+                Ema::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -1308,10 +1293,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-            ],
             vec![OutField { node: 2, field: 0, name: "x".into() }],
         )
     }
@@ -1326,7 +1307,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         let flat = bp.compile().expect("valid composite");
@@ -1364,7 +1344,6 @@ mod tests {
                 Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None },
                 Role { name: "price2".into(), targets: vec![Target { node: 1, slot: 0 }], source: None },
             ],
-            vec![],
             vec![
                 OutField { node: 0, field: 0, name: "a".into() },
                 OutField { node: 1, field: 0, name: "b".into() },
@@ -1382,7 +1361,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }, Target { node: 0, slot: 1 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         let flat = bp.compile().expect("valid multi-output composite");
@@ -1416,7 +1394,6 @@ mod tests {
             vec![BlueprintNode::Composite(inner)],
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -1426,7 +1403,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         let flat = bp.compile().expect("valid nested composite");
@@ -1460,7 +1436,6 @@ mod tests {
                 Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None },
                 Role { name: "price2".into(), targets: vec![Target { node: 1, slot: 0 }], source: None },
             ],
-            vec![],
             vec![
                 OutField { node: 0, field: 0, name: "a".into() },
                 OutField { node: 1, field: 0, name: "b".into() },
@@ -1474,7 +1449,6 @@ mod tests {
                 Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }, // outer role 0 -> inner role 0
                 Role { name: "price2".into(), targets: vec![Target { node: 0, slot: 1 }], source: None }, // outer role 1 -> inner role 1
             ],
-            vec![],
             vec![
                 OutField { node: 0, field: 0, name: "x".into() }, // inner field 0
                 OutField { node: 0, field: 1, name: "y".into() }, // inner field 1 (nested arm)
@@ -1490,7 +1464,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }, Target { node: 0, slot: 1 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         let flat = bp.compile().expect("valid nested multi-output");
@@ -1513,7 +1486,6 @@ mod tests {
             vec![pass1()],
             vec![Edge { from: 0, to: 9, slot: 0, from_field: 0 }],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -1521,7 +1493,6 @@ mod tests {
             vec![BlueprintNode::Composite(c)],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         // the Ok arm holds Box<dyn Node> (not Debug), so assert via the Err arm.
@@ -1530,8 +1501,8 @@ mod tests {
 
     #[test]
     fn indistinguishable_fan_in_rejected() {
-        // two alias-less Sma (each an unaliased `length`) on role price into a Sub:
-        // signatures collide ("Sp"=="Sp") and a param is unaliased -> fault.
+        // two default-named Sma (both "sma", each a `length` param) on role price
+        // into a Sub: node-name signatures collide and a param is present -> fault.
         let c = Composite::new(
             "ambig",
             vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
@@ -1542,7 +1513,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![],
             vec![OutField { node: 2, field: 0, name: "x".into() }],
         );
         let bp = Composite::new(
@@ -1552,7 +1522,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         assert_eq!(bp.compile().err(), Some(CompileError::IndistinguishableFanIn { node: 2 }));
@@ -1569,7 +1538,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         assert!(bp.compile().is_ok(), "param-less interchangeable fan-in must compile");
@@ -1585,7 +1553,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -1593,7 +1560,6 @@ mod tests {
             vec![BlueprintNode::Composite(c)],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         // the Ok arm holds Box<dyn Node> (not Debug), so assert via the Err arm.
@@ -1608,7 +1574,6 @@ mod tests {
             vec![pass1()],
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 5, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -1616,7 +1581,6 @@ mod tests {
             vec![BlueprintNode::Composite(c)],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         // the Ok arm holds Box<dyn Node> (not Debug), so assert via the Err arm.
@@ -1632,7 +1596,6 @@ mod tests {
             vec![pass1()],
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "a".into() }],
         );
         let bp = Composite::new(
@@ -1642,7 +1605,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         assert_eq!(bp.compile().err(), Some(CompileError::BadInteriorIndex));
@@ -1657,7 +1619,6 @@ mod tests {
             vec![pass1(), sink_i64()],
             vec![Edge { from: 0, to: 1, slot: 0, from_field: 0 }],
             vec![],
-            vec![], // params
             vec![], // output
         );
         match bp.bootstrap().unwrap_err() {
@@ -1747,7 +1708,11 @@ mod tests {
     fn sma_cross() -> Composite {
         Composite::new(
             "sma_cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+            vec![
+                Sma::builder().named("fast").into(),
+                Sma::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -1755,10 +1720,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-            ],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         )
     }
@@ -1793,7 +1754,6 @@ mod tests {
                     Target { node: 2, slot: 1 }, // price -> SimBroker price slot
                 ], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         (bp, rx_eq, rx_ex)
@@ -1851,7 +1811,6 @@ mod tests {
                 Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None },
                 Role { name: "price2".into(), targets: vec![Target { node: 1, slot: 0 }], source: None },
             ],
-            vec![],
             vec![
                 OutField { node: 0, field: 0, name: "a".into() },
                 OutField { node: 1, field: 0, name: "b".into() },
@@ -1871,7 +1830,6 @@ mod tests {
             vec![
                 Role { name: "src".into(), targets: vec![Target { node: 0, slot: 0 }, Target { node: 0, slot: 1 }], source: Some(ScalarKind::F64) },
             ],
-            vec![], // params
             vec![], // output
         );
         let mut h = bp
@@ -1980,7 +1938,7 @@ mod tests {
         // scale (F64); Sub/SimBroker/Recorder declare none
         assert_eq!(
             space.iter().map(|p| p.name.as_str()).collect::<Vec<_>>(),
-            ["sma_cross.fast", "sma_cross.slow", "scale"],
+            ["sma_cross.fast.length", "sma_cross.slow.length", "exposure.scale"],
         );
         assert_eq!(
             space.iter().map(|p| p.kind).collect::<Vec<_>>(),
@@ -1988,137 +1946,17 @@ mod tests {
         );
     }
 
-    #[test]
-    fn param_alias_relabels_param_space_name_in_place() {
-        // two Sma leaves (each one `length` param) under a composite that aliases
-        // slot 0 of node 0 -> "shortLen" and slot 0 of node 1 -> "longLen".
-        let c = Composite::new(
-            "cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
-            vec![
-                Edge { from: 0, to: 2, slot: 0, from_field: 0 },
-                Edge { from: 1, to: 2, slot: 1, from_field: 0 },
-            ],
-            vec![Role {
-                name: "price".into(),
-                targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![
-                ParamAlias { name: "shortLen".into(), node: 0, slot: 0 },
-                ParamAlias { name: "longLen".into(), node: 1, slot: 0 },
-            ],
-            vec![OutField { node: 2, field: 0, name: "out".into() }],
-        );
-        let bp = Composite::new(
-            "root",
-            vec![BlueprintNode::Composite(c)],
-            vec![],
-            vec![],
-            vec![], // params
-            vec![], // output
-        );
-        let names: Vec<String> = bp.param_space().into_iter().map(|p| p.name).collect();
-        // aliased in place: names are the aliases, NOT two duplicate "cross.length".
-        assert_eq!(names, vec!["cross.shortLen".to_string(), "cross.longLen".to_string()]);
-    }
-
-    #[test]
-    fn out_of_range_param_alias_rejected() {
-        // alias names node 9 (no such interior item) -> caught at compile.
-        let c = Composite::new(
-            "cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
-            vec![
-                Edge { from: 0, to: 2, slot: 0, from_field: 0 },
-                Edge { from: 1, to: 2, slot: 1, from_field: 0 },
-            ],
-            vec![Role {
-                name: "price".into(),
-                targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![ParamAlias { name: "bogus".into(), node: 9, slot: 0 }],
-            vec![OutField { node: 2, field: 0, name: "out".into() }],
-        );
-        let bp = Composite::new(
-            "root",
-            vec![BlueprintNode::Composite(c)],
-            vec![],
-            vec![
-                Role { name: "src".into(), targets: vec![], source: Some(ScalarKind::F64) },
-            ],
-            vec![], // params
-            vec![], // output
-        );
-        // two Sma leaves => two i64 length slots; supply a matching vector so the
-        // ONLY error is the bad alias, not arity. (The Ok arm holds Box<dyn Node>,
-        // not Debug, so assert via the Err arm — as the other reject tests do.)
-        assert_eq!(
-            bp.compile_with_params(&[Scalar::I64(2), Scalar::I64(4)]).err(),
-            Some(CompileError::BadInteriorIndex),
-        );
-    }
-
-    #[test]
-    fn unaliased_params_keep_factory_names() {
-        // no aliases => param_space identical to the pre-#41 path-qualified names.
-        let c = Composite::new(
-            "cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
-            vec![
-                Edge { from: 0, to: 2, slot: 0, from_field: 0 },
-                Edge { from: 1, to: 2, slot: 1, from_field: 0 },
-            ],
-            vec![Role {
-                name: "price".into(),
-                targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![],
-            vec![OutField { node: 2, field: 0, name: "out".into() }],
-        );
-        let bp = Composite::new(
-            "root",
-            vec![BlueprintNode::Composite(c)],
-            vec![],
-            vec![],
-            vec![], // params
-            vec![], // output
-        );
-        let names: Vec<String> = bp.param_space().into_iter().map(|p| p.name).collect();
-        assert_eq!(names, vec!["cross.length".to_string(), "cross.length".to_string()]);
-    }
-
-    #[test]
-    fn partial_aliasing_relabels_only_the_named_slot() {
-        // alias node 0 only; node 1 keeps its factory name; order intact.
-        let c = Composite::new(
-            "cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
-            vec![
-                Edge { from: 0, to: 2, slot: 0, from_field: 0 },
-                Edge { from: 1, to: 2, slot: 1, from_field: 0 },
-            ],
-            vec![Role {
-                name: "price".into(),
-                targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![ParamAlias { name: "shortLen".into(), node: 0, slot: 0 }],
-            vec![OutField { node: 2, field: 0, name: "out".into() }],
-        );
-        let bp = Composite::new(
-            "root",
-            vec![BlueprintNode::Composite(c)],
-            vec![],
-            vec![],
-            vec![], // params
-            vec![], // output
-        );
-        let names: Vec<String> = bp.param_space().into_iter().map(|p| p.name).collect();
-        assert_eq!(names, vec!["cross.shortLen".to_string(), "cross.length".to_string()]);
-    }
-
     #[test]
     fn param_space_is_flat_path_qualified_and_slot_disambiguated() {
         use aura_std::{LinComb, Sma, Sub};
-        // inner composite "fast_slow": two SMAs (same type → same param name) + a Sub
+        // inner composite "fast_slow": two named SMAs (fast/slow) + a Sub
         let fast_slow = Composite::new(
             "fast_slow",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+            vec![
+                Sma::builder().named("fast").into(),
+                Sma::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -2126,7 +1964,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         );
         // outer composite "strategy": the inner composite + a LinComb([1,-1])
@@ -2135,7 +1972,6 @@ mod tests {
             vec![BlueprintNode::Composite(fast_slow), LinComb::builder(2).into()],
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -2143,7 +1979,6 @@ mod tests {
             vec![BlueprintNode::Composite(strategy)],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
 
@@ -2152,10 +1987,10 @@ mod tests {
         assert_eq!(
             names,
             [
-                "strategy.fast_slow.length", // slot 0 — Sma(2)
-                "strategy.fast_slow.length", // slot 1 — Sma(4): same name, distinct slot
-                "strategy.weights[0]",       // slot 2 — LinComb weight 0
-                "strategy.weights[1]",       // slot 3 — LinComb weight 1
+                "strategy.fast_slow.fast.length", // slot 0 — Sma "fast"
+                "strategy.fast_slow.slow.length", // slot 1 — Sma "slow"
+                "strategy.lincomb.weights[0]",    // slot 2 — LinComb weight 0
+                "strategy.lincomb.weights[1]",    // slot 3 — LinComb weight 1
             ]
         );
         assert_eq!(space[0].kind, ScalarKind::I64);
@@ -2180,7 +2015,11 @@ mod tests {
         // isolated path-qualification test above)
         let fast_slow = Composite::new(
             "fast_slow",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+            vec![
+                Sma::builder().named("fast").into(),
+                Sma::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -2188,10 +2027,6 @@ mod tests {
             vec![Role {
                 name: "price".into(),
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }], source: None, }],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-            ],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         );
         // outer composite "strategy": the inner composite + a LinComb([1,-1])
@@ -2200,7 +2035,6 @@ mod tests {
             vec![BlueprintNode::Composite(fast_slow), LinComb::builder(2).into()],
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "out".into() }],
         );
         let bp = Composite::new(
@@ -2208,7 +2042,6 @@ mod tests {
             vec![BlueprintNode::Composite(strategy)],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
 
@@ -2240,19 +2073,13 @@ mod tests {
     }
 
     #[test]
-    fn top_level_leaf_params_are_unqualified() {
+    fn top_level_leaf_params_carry_the_node_segment() {
         use aura_std::Sma;
-        let bp = Composite::new(
-            "root",
-            vec![Sma::builder().into()],
-            vec![],
-            vec![],
-            vec![], // params
-            vec![], // output
-        );
+        let bp = Composite::new("root", vec![Sma::builder().into()], vec![], vec![], vec![]);
         let space = bp.param_space();
         assert_eq!(space.len(), 1);
-        assert_eq!(space[0].name, "length"); // no path prefix at the top level
+        // the root node now carries its own node-name segment (default "sma")
+        assert_eq!(space[0].name, "sma.length");
     }
 
     #[test]
@@ -2263,7 +2090,6 @@ mod tests {
             vec![Sma::builder().into(), LinComb::builder(2).into()],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         assert_eq!(bp.param_space(), bp.param_space()); // pure structural function (C1)
@@ -2278,7 +2104,6 @@ mod tests {
             vec![Sub::builder().into(), Add::builder().into()],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         assert!(only_paramless.param_space().is_empty());
@@ -2287,7 +2112,6 @@ mod tests {
             vec![],
             vec![],
             vec![],
-            vec![], // params
             vec![], // output
         );
         assert!(empty.param_space().is_empty());
@@ -2301,11 +2125,11 @@ mod tests {
         Composite::new(
             "macd",
             vec![
-                Ema::builder().into(), // 0 fast EMA
-                Ema::builder().into(), // 1 slow EMA
-                Sub::builder().into(), // 2 macd = fast - slow
-                Ema::builder().into(), // 3 signal EMA of macd
-                Sub::builder().into(), // 4 histogram = macd - signal
+                Ema::builder().named("fast").into(), // 0 fast EMA
+                Ema::builder().named("slow").into(),  // 1 slow EMA
+                Sub::builder().into(),                // 2 macd = fast - slow
+                Ema::builder().named("signal").into(), // 3 signal EMA of macd
+                Sub::builder().into(),                // 4 histogram = macd - signal
             ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
@@ -2315,11 +2139,6 @@ mod tests {
                 Edge { from: 3, to: 4, slot: 1, from_field: 0 },
             ],
             vec![root_role("price", vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }])],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-                ParamAlias { name: "signal".into(), node: 3, slot: 0 },
-            ],
             vec![
                 OutField { node: 2, field: 0, name: "macd".into() },
                 OutField { node: 3, field: 0, name: "signal".into() },
@@ -2366,7 +2185,6 @@ mod tests {
             vec![Edge { from: 0, to: 1, slot: 0, from_field: 0 }], // f64 -> i64 slot
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: Some(ScalarKind::F64) }],
             vec![],
-            vec![],
         );
         let err = root.compile_with_params(&[Scalar::I64(3)]);
         // kind fault caught pre-build (no panic) — same variant bootstrap would give
@@ -2384,7 +2202,6 @@ mod tests {
             vec![],
             vec![Role { name: "price".into(), targets: vec![Target { node: 0, slot: 0 }], source: None }],
             vec![],
-            vec![],
         );
         // the Ok arm holds a FlatGraph (not Debug), so assert via the Err arm.
         assert_eq!(
diff --git a/crates/aura-engine/src/graph_model.rs b/crates/aura-engine/src/graph_model.rs
index 0c9541c..7770d17 100644
--- a/crates/aura-engine/src/graph_model.rs
+++ b/crates/aura-engine/src/graph_model.rs
@@ -232,7 +232,7 @@ pub fn model_to_json(root: &Composite) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{Edge, OutField, ParamAlias, Role, Target};
+    use crate::{Edge, OutField, Role, Target};
     use aura_core::{
         FieldSpec, Node, NodeSchema, PortSpec, PrimitiveBuilder, Scalar,
     };
@@ -273,7 +273,11 @@ mod tests {
     fn sma_cross() -> Composite {
         Composite::new(
             "sma_cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+            vec![
+                Sma::builder().named("fast").into(),
+                Sma::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -283,10 +287,6 @@ mod tests {
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }],
                 source: None,
             }],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-            ],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         )
     }
@@ -315,7 +315,6 @@ mod tests {
                 targets: vec![Target { node: 0, slot: 0 }], // price -> sma_cross role 0
                 source: Some(ScalarKind::F64),
             }],
-            vec![], // params: the interior sma_cross carries the aliases
             vec![], // output: the root ends in a sink, no re-export
         )
     }
@@ -331,7 +330,6 @@ mod tests {
                 Role { name: "a".into(), targets: vec![Target { node: 0, slot: 0 }], source: None },
                 Role { name: "b".into(), targets: vec![Target { node: 1, slot: 0 }], source: None },
             ],
-            vec![],
             vec![OutField { node: 0, field: 0, name: "v".into() }],
         )
     }
@@ -358,7 +356,6 @@ mod tests {
                 source: Some(ScalarKind::F64),
             }],
             vec![],
-            vec![],
         )
     }
 
diff --git a/crates/aura-engine/src/lib.rs b/crates/aura-engine/src/lib.rs
index aa21628..e78b52f 100644
--- a/crates/aura-engine/src/lib.rs
+++ b/crates/aura-engine/src/lib.rs
@@ -38,8 +38,8 @@ mod report;
 mod sweep;
 
 pub use blueprint::{
-    aliases_on, signature_of, BindError, Binder, BlueprintNode, CompileError, Composite, OutField,
-    ParamAlias, Role, SweepBinder,
+    signature_of, BindError, Binder, BlueprintNode, CompileError, Composite, OutField, Role,
+    SweepBinder,
 };
 pub use graph_model::model_to_json;
 pub use harness::{BootstrapError, Edge, FlatGraph, Harness, SourceSpec, Target};
diff --git a/crates/aura-engine/src/sweep.rs b/crates/aura-engine/src/sweep.rs
index 4c69bdc..9739d15 100644
--- a/crates/aura-engine/src/sweep.rs
+++ b/crates/aura-engine/src/sweep.rs
@@ -170,8 +170,7 @@ where
 mod tests {
     use super::*;
     use crate::{
-        f64_field, summarize, BlueprintNode, Composite, Edge, OutField, ParamAlias, Role,
-        RunManifest, Target,
+        f64_field, summarize, BlueprintNode, Composite, Edge, OutField, Role, RunManifest, Target,
     };
     use aura_core::{Firing, ParamSpec, Scalar, ScalarKind, Timestamp};
     use aura_std::{Exposure, Recorder, SimBroker, Sma, Sub};
@@ -275,7 +274,11 @@ mod tests {
     fn sma_cross() -> Composite {
         Composite::new(
             "sma_cross",
-            vec![Sma::builder().into(), Sma::builder().into(), Sub::builder().into()],
+            vec![
+                Sma::builder().named("fast").into(),
+                Sma::builder().named("slow").into(),
+                Sub::builder().into(),
+            ],
             vec![
                 Edge { from: 0, to: 2, slot: 0, from_field: 0 },
                 Edge { from: 1, to: 2, slot: 1, from_field: 0 },
@@ -285,10 +288,6 @@ mod tests {
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 1, slot: 0 }],
                 source: None,
             }],
-            vec![
-                ParamAlias { name: "fast".into(), node: 0, slot: 0 },
-                ParamAlias { name: "slow".into(), node: 1, slot: 0 },
-            ],
             vec![OutField { node: 2, field: 0, name: "out".into() }],
         )
     }
@@ -323,7 +322,6 @@ mod tests {
                 targets: vec![Target { node: 0, slot: 0 }, Target { node: 2, slot: 1 }],
                 source: Some(ScalarKind::F64),
             }],
-            vec![], // params: the interior sma_cross + Exposure carry the knobs
             vec![], // output: the root ends in sinks
         );
         (bp, rx_eq, rx_ex)
diff --git a/docs/design/INDEX.md b/docs/design/INDEX.md
index 247299f..bc50328 100644
--- a/docs/design/INDEX.md
+++ b/docs/design/INDEX.md
@@ -349,30 +349,33 @@ its producing node as a `name := …` binding; originally `[out:<name>]` markers
 but are dropped at lowering — `ItemLowering::Composite.output` is `Vec<(usize,
 usize)>`, raw index pairs only, so the compilat is name-free (verified: the
 compiled-view render stayed bit-identical across this change).
-**Realization (cycle 0019 — name the composite boundary, #41).** The same
-named-projection shape now covers the other two boundary edge-kinds, so **all
-three** are uniform: `input_roles` is a `Vec<Role { name, targets }>` (was a bare
-`Vec<Vec<Target>>`) and a composite carries `params: Vec<ParamAlias { name, node,
-slot }>`, alongside `output: Vec<OutField>`. Each is an ordered, positionally-indexed
-**named projection** of interior handles. Param aliasing is a **pure naming overlay**,
-not curation: `param_space()` relabels an aliased slot's surface name **in place** —
-slot order, arity, and kinds are unchanged, so the sweep surface is identical and the
-`param_space_mirrors_compiled_flat_node_param_order` anchor stays green. Like the
-output names, role and param **names** are **non-load-bearing** (C23): they live at
-the blueprint boundary and in render (`[in:<name>]` / `[param:<name>]` markers) but
-are dropped at lowering — the compilat is wired by raw index and a dangling alias is
-rejected at compile (`BadInteriorIndex`), not silently lowered. The full composite
-boundary signature (named inputs, params, multi-outputs) is now legible without
-changing the compilat.
-**Refinement (fan-in distinguishability, 2026-06-08).** A fan-in node (>1 input)
-is well-formed only if its colliding sources — sources with equal recursive
-signatures (type initial + alias initials + recursive input signatures) — do not
-hide an unnamed configuration axis: a collision is a `CompileError`
-(`IndistinguishableFanIn`) when at least one colliding source carries an
-unaliased param slot. Genuinely-interchangeable sources (equal signatures, no
-param) stay legal. Construction-phase only; the compilat stays name-free (C23).
-The graph view renders each fan-in input as the shortest sibling-unique prefix
-of its source signature.
+**Realization (cycle 0019 — name the composite boundary, #41; param-overlay retired,
+cycle 0031).** The named-projection shape covers the surviving boundary edge-kinds:
+`input_roles` is a `Vec<Role { name, targets }>` (was a bare `Vec<Vec<Target>>`),
+alongside `output: Vec<OutField>`. Each is an ordered, positionally-indexed
+**named projection** of interior handles. **Param projection is no longer a
+composite overlay** (the index-addressed `ParamAlias` was retired in cycle 0031):
+a node's surface param name flows from its own **instance name** — every node
+carries a name (default = its lowercased type label, override via `.named()`), and
+`param_space()` is uniformly `<node>.<param>` at every level including the root. A
+same-type fan-in is distinguished by naming the colliding legs, the same single act
+that qualifies their param paths. Like the output and role names, **node names are
+non-load-bearing** (C23): they live at the blueprint boundary and in render but are
+dropped at lowering — the compilat is wired by raw index. The full composite
+boundary signature (named inputs, multi-outputs) and the per-node param path are
+legible without changing the compilat.
+**Refinement (fan-in distinguishability, 2026-06-08; node-name keying, cycle 0031).**
+A fan-in node (>1 input) is well-formed only if its colliding sources — sources
+with equal recursive **node-name** signatures (each node contributes its name —
+the instance name, default = the lowercased type label — then its inputs'
+signatures in slot order, stopping at a named source) — do not hide an unnamed
+configuration axis: a collision is a `CompileError` (`IndistinguishableFanIn`)
+when at least one colliding source carries a **param** (a param-bearing same-name
+collision), resolved by giving the colliding nodes distinct names. Paramless
+interchangeable same-name sources (equal signatures, no param) stay legal.
+Construction-phase only; the compilat stays name-free (C23). The graph view
+renders each fan-in input as the shortest sibling-unique prefix of its source
+signature.
 
 ### C10 — Strategy output is an intent/exposure stream; position management is a decoupled derived layer; brokers are downstream nodes
 **Guarantee.** A strategy's primary, backtestable output is **not** an equity