diff --git a/imprint.el b/imprint.el
new file mode 100644
index 0000000..86c3080
--- /dev/null
+++ b/imprint.el
@@ -0,0 +1,81 @@
+// Layer 3 — Imprint
+// Domain knowledge, voice, and tools bounded by the L2 stewardship surface.
+// Imprints cannot write BellEvent or StewardshipEvent nodes.
+// Lower layers (L0 core, L1 safety, L2 stewardship) are structurally inaccessible from here.
+
+// imprint_current — returns the active imprint ID from state.
+// Falls back to "base" (bare Neuron, no suit) when nothing is loaded.
+fn imprint_current() -> String {
+    let id: String = state_get("active_imprint_id")
+    return if str_eq(id, "") { "base" } else { id }
+}
+
+// imprint_load — activate an imprint by ID.
+// Searches engram for a node labelled "imprint:<id>".
+// Verifies the returned node's label matches before accepting the match.
+// On success: sets active_imprint_id state and returns {"ok":true,"id":"<id>"}.
+// On miss: returns {"ok":false,"error":"imprint not found: <id>"}.
+fn imprint_load(imprint_id: String) -> String {
+    let label: String = "imprint:" + imprint_id
+    let results: String = engram_search_json(label, 1)
+    if str_eq(results, "") {
+        return "{\"ok\":false,\"error\":\"imprint not found: " + imprint_id + "\"}"
+    }
+    if str_eq(results, "[]") {
+        return "{\"ok\":false,\"error\":\"imprint not found: " + imprint_id + "\"}"
+    }
+    let found_label: String = json_get(results, "label")
+    if str_eq(found_label, label) {
+        state_set("active_imprint_id", imprint_id)
+        return "{\"ok\":true,\"id\":\"" + imprint_id + "\"}"
+    }
+    return "{\"ok\":false,\"error\":\"imprint not found: " + imprint_id + "\"}"
+}
+
+// imprint_respond — route steward-aligned input through the active imprint's voice/domain context.
+// If imprint_id is "base" or empty: pass input through unchanged (base Neuron, no suit).
+// If the imprint is confirmed loaded in state: annotate the input with imprint context.
+// If the state does not match: graceful fallback to base — never hard-fail at L3.
+fn imprint_respond(input: String, imprint_id: String) -> String {
+    if str_eq(imprint_id, "base") {
+        return input
+    }
+    if str_eq(imprint_id, "") {
+        return input
+    }
+    // Cross-check imprint_id against loaded state rather than re-querying engram
+    let current: String = imprint_current()
+    if str_eq(current, imprint_id) {
+        return input + " [imprint:" + imprint_id + " active]"
+    }
+    // Graceful fallback: imprint not loaded in state, return input unchanged
+    return input
+}
+
+// imprint_surface_knowledge — domain-scoped knowledge search for the active imprint.
+// Imprints can search knowledge but only domain-relevant nodes.
+// For "base" imprint: full query, no scope restriction.
+// For named imprints: query is narrowed to "domain:<imprint_id>" scope.
+fn imprint_surface_knowledge(query: String, imprint_id: String) -> String {
+    if str_eq(imprint_id, "base") {
+        return engram_search_json(query, 10)
+    }
+    if str_eq(imprint_id, "") {
+        return engram_search_json(query, 10)
+    }
+    let scoped_query: String = query + " domain:" + imprint_id
+    return engram_search_json(scoped_query, 10)
+}
+
+// imprint_surface_memory_read — imprints can read memories from engram.
+// Read-only: no write surface is exposed here.
+// Imprints CANNOT write BellEvent, StewardshipEvent, or InternalStateEvent nodes —
+// those write paths are sealed in L1 and L2, which are structurally inaccessible.
+fn imprint_surface_memory_read(query: String) -> String {
+    return engram_search_json(query, 10)
+}
+
+// imprint_unload — deactivate the current imprint, returning to base Neuron.
+fn imprint_unload() -> Void {
+    state_set("active_imprint_id", "")
+}
diff --git a/imprint.elh b/imprint.elh
new file mode 100644
index 0000000..8a29f42
--- /dev/null
+++ b/imprint.elh
@@ -0,0 +1,7 @@
+// auto-generated by elc --emit-header — do not edit
+extern fn imprint_current() -> String
+extern fn imprint_load(imprint_id: String) -> String
+extern fn imprint_respond(input: String, imprint_id: String) -> String
+extern fn imprint_surface_knowledge(query: String, imprint_id: String) -> String
+extern fn imprint_surface_memory_read(query: String) -> String
+extern fn imprint_unload() -> Void
diff --git a/tests/test_imprint.el b/tests/test_imprint.el
new file mode 100644
index 0000000..596d5b0
--- /dev/null
+++ b/tests/test_imprint.el
@@ -0,0 +1,274 @@
+// tests/test_imprint.el
+// Comprehensive test suite for imprint.el (Layer 3 boundary).
+//
+// El has no native test framework. Tests are plain El programs that
+// call functions, compare results, and print PASS/FAIL via println.
+// Each test is a fn returning Int: 0 = pass, 1 = fail.
+// run_all() drives them and returns a final summary line.
+//
+// Syntax rules observed:
+//   - No Bool type annotation — inference only
+//   - No && / || — nested if/else used instead
+//   - No unary ! — inverted with if/else
+//   - No closures or lambdas
+
+import "imprint.elh"
+
+// ---------------------------------------------------------------------------
+// helpers
+// ---------------------------------------------------------------------------
+
+fn assert_eq(label: String, got: String, want: String) -> Int {
+    if str_eq(got, want) {
+        println("PASS  " + label)
+        return 0
+    }
+    println("FAIL  " + label + "  got=" + got + "  want=" + want)
+    return 1
+}
+
+fn assert_not_eq(label: String, got: String, not_want: String) -> Int {
+    if str_eq(got, not_want) {
+        println("FAIL  " + label + "  got=" + got + "  (should differ)")
+        return 1
+    }
+    println("PASS  " + label)
+    return 0
+}
+
+fn assert_contains(label: String, haystack: String, needle: String) -> Int {
+    if str_contains(haystack, needle) {
+        println("PASS  " + label)
+        return 0
+    }
+    println("FAIL  " + label + "  value=" + haystack + "  missing=" + needle)
+    return 1
+}
+
+fn assert_not_contains(label: String, haystack: String, needle: String) -> Int {
+    if str_contains(haystack, needle) {
+        println("FAIL  " + label + "  value=" + haystack + "  unexpected=" + needle)
+        return 1
+    }
+    println("PASS  " + label)
+    return 0
+}
+
+fn assert_not_empty(label: String, got: String) -> Int {
+    if str_eq(got, "") {
+        println("FAIL  " + label + "  got empty string")
+        return 1
+    }
+    println("PASS  " + label)
+    return 0
+}
+
+// ---------------------------------------------------------------------------
+// TEST 1
+// imprint_current() with no prior state should return "base".
+// We cannot guarantee a clean state across runs so we call imprint_unload()
+// first to normalise, then check.
+// ---------------------------------------------------------------------------
+fn test_01_current_after_unload_is_base() -> Int {
+    imprint_unload()
+    let id: String = imprint_current()
+    return assert_eq("01 imprint_current after unload == base", id, "base")
+}
+
+// ---------------------------------------------------------------------------
+// TEST 2
+// imprint_unload() then imprint_current() always returns "base".
+// Calling unload twice must be idempotent.
+// ---------------------------------------------------------------------------
+fn test_02_unload_idempotent() -> Int {
+    imprint_unload()
+    imprint_unload()
+    let id: String = imprint_current()
+    return assert_eq("02 double-unload still base", id, "base")
+}
+
+// ---------------------------------------------------------------------------
+// TEST 3
+// imprint_load() with a nonexistent ID must return ok==false and an error
+// message that mentions the requested ID.
+// We use a UUID-like name that will never exist in the engram.
+// ---------------------------------------------------------------------------
+fn test_03_load_nonexistent_returns_ok_false() -> Int {
+    let result: String = imprint_load("__test_ghost_imprint_xyz__")
+    let ok_field: String = json_get(result, "ok")
+    let fails: Int = 0
+    let fails = fails + assert_eq("03a load nonexistent ok==false", ok_field, "false")
+    let fails = fails + assert_contains("03b load nonexistent error mentions id", result, "__test_ghost_imprint_xyz__")
+    return if fails > 0 { 1 } else { 0 }
+}
+
+// ---------------------------------------------------------------------------
+// TEST 4
+// json_get on imprint_load result should always return the "ok" field.
+// Both ok=true and ok=false payloads must carry the field.
+// We test the miss case (guaranteed) for the field's presence.
+// ---------------------------------------------------------------------------
+fn test_04_load_result_has_ok_field() -> Int {
+    let result: String = imprint_load("__test_field_check__")
+    let ok_field: String = json_get(result, "ok")
+    return assert_not_empty("04 load result contains ok field", ok_field)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 5
+// imprint_respond() with imprint_id == "base" must return input unchanged.
+// The base path is the identity function — no annotation is added.
+// ---------------------------------------------------------------------------
+fn test_05_respond_base_passthrough() -> Int {
+    let input: String = "Hello from the base layer."
+    let output: String = imprint_respond(input, "base")
+    return assert_eq("05 respond with base id == passthrough", output, input)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 6
+// imprint_respond() with imprint_id == "" (empty string) must also return
+// input unchanged — empty string is treated as base.
+// ---------------------------------------------------------------------------
+fn test_06_respond_empty_id_passthrough() -> Int {
+    let input: String = "Test input for empty imprint_id."
+    let output: String = imprint_respond(input, "")
+    return assert_eq("06 respond with empty id == passthrough", output, input)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 7
+// imprint_respond() with an unknown imprint_id (node not in engram) must
+// fall back gracefully and return input unchanged.
+// The spec says: never hard-fail at L3 — graceful fallback to base.
+// ---------------------------------------------------------------------------
+fn test_07_respond_unknown_id_graceful_fallback() -> Int {
+    let input: String = "Graceful fallback test payload."
+    let output: String = imprint_respond(input, "__no_such_imprint_ever__")
+    return assert_eq("07 respond unknown id graceful fallback == passthrough", output, input)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 8
+// After imprint_unload(), imprint_respond should produce base behaviour.
+// We call respond with the just-cleared state ID ("base") to confirm
+// the unload/respond pipeline produces the identity transform.
+// ---------------------------------------------------------------------------
+fn test_08_respond_after_unload_is_passthrough() -> Int {
+    imprint_unload()
+    let current: String = imprint_current()
+    let input: String = "Post-unload response passthrough check."
+    let output: String = imprint_respond(input, current)
+    return assert_eq("08 respond after unload == passthrough", output, input)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 9
+// imprint_surface_knowledge() must return a String (not crash, not empty
+// in a way that signals an error code). We test both base and named paths.
+// For "base" the query is passed directly; for a named imprint the query
+// is scoped but the return must still be a String.
+// ---------------------------------------------------------------------------
+fn test_09_surface_knowledge_returns_string() -> Int {
+    let result_base: String = imprint_surface_knowledge("test query", "base")
+    // Must be a String — "" or "[]" is valid (no matching nodes), but the
+    // call must not return an error token. We check it is not the literal
+    // string "error" to catch any error-signalling convention.
+    let fails: Int = 0
+    let fails = fails + assert_not_eq("09a surface_knowledge base != error", result_base, "error")
+    let result_named: String = imprint_surface_knowledge("test query", "demo-imprint")
+    let fails = fails + assert_not_eq("09b surface_knowledge named != error", result_named, "error")
+    // Scoped query must embed the domain scope string
+    // (test indirectly: the scoped call does not crash and returns a String)
+    let fails = fails + assert_not_eq("09c surface_knowledge named != crash sentinel", result_named, "CRASH")
+    return if fails > 0 { 1 } else { 0 }
+}
+
+// ---------------------------------------------------------------------------
+// TEST 10
+// imprint_surface_memory_read() must return a String for any query.
+// This is a read-only engram search — it must never write.
+// We check the return is not an error sentinel and is a valid String.
+// ---------------------------------------------------------------------------
+fn test_10_surface_memory_read_returns_string() -> Int {
+    let result: String = imprint_surface_memory_read("soul memory test")
+    let fails: Int = 0
+    let fails = fails + assert_not_eq("10a surface_memory_read != error", result, "error")
+    let fails = fails + assert_not_eq("10b surface_memory_read != crash", result, "CRASH")
+    return if fails > 0 { 1 } else { 0 }
+}
+
+// ---------------------------------------------------------------------------
+// TEST 11
+// imprint_surface_knowledge() with empty imprint_id uses the base path
+// (no domain scoping) — must behave identically to base.
+// ---------------------------------------------------------------------------
+fn test_11_surface_knowledge_empty_id_equals_base() -> Int {
+    let base_result: String = imprint_surface_knowledge("neuron layer test", "base")
+    let empty_result: String = imprint_surface_knowledge("neuron layer test", "")
+    return assert_eq("11 surface_knowledge empty id == base id", empty_result, base_result)
+}
+
+// ---------------------------------------------------------------------------
+// TEST 12
+// imprint_respond() must NOT annotate when imprint_id is "base" — the
+// "[imprint:" marker must be absent in the output.
+// ---------------------------------------------------------------------------
+fn test_12_respond_base_no_annotation() -> Int {
+    let input: String = "No annotation expected."
+    let output: String = imprint_respond(input, "base")
+    return assert_not_contains("12 respond base has no imprint annotation", output, "[imprint:")
+}
+
+// ---------------------------------------------------------------------------
+// TEST 13
+// imprint_load() with empty-string ID must return ok==false.
+// An empty ID is not a valid imprint identifier.
+// ---------------------------------------------------------------------------
+fn test_13_load_empty_id_returns_ok_false() -> Int {
+    let result: String = imprint_load("")
+    let ok_field: String = json_get(result, "ok")
+    return assert_eq("13 load empty id ok==false", ok_field, "false")
+}
+
+// ---------------------------------------------------------------------------
+// TEST 14
+// After a failed imprint_load(), imprint_current() must still return "base"
+// — a failed load must leave state untouched.
+// ---------------------------------------------------------------------------
+fn test_14_failed_load_does_not_mutate_state() -> Int {
+    imprint_unload()
+    let discard: String = imprint_load("__nonexistent_for_state_test__")
+    let id: String = imprint_current()
+    return assert_eq("14 failed load leaves state as base", id, "base")
+}
+
+// ---------------------------------------------------------------------------
+// run_all — executes every test and prints a summary.
+// Returns total failure count as Int.
+// ---------------------------------------------------------------------------
+fn run_all() -> Int {
+    println("=== imprint.el test suite ===")
+    let total: Int = 0
+    let failed: Int = 0
+
+    let failed = failed + test_01_current_after_unload_is_base()
+    let failed = failed + test_02_unload_idempotent()
+    let failed = failed + test_03_load_nonexistent_returns_ok_false()
+    let failed = failed + test_04_load_result_has_ok_field()
+    let failed = failed + test_05_respond_base_passthrough()
+    let failed = failed + test_06_respond_empty_id_passthrough()
+    let failed = failed + test_07_respond_unknown_id_graceful_fallback()
+    let failed = failed + test_08_respond_after_unload_is_passthrough()
+    let failed = failed + test_09_surface_knowledge_returns_string()
+    let failed = failed + test_10_surface_memory_read_returns_string()
+    let failed = failed + test_11_surface_knowledge_empty_id_equals_base()
+    let failed = failed + test_12_respond_base_no_annotation()
+    let failed = failed + test_13_load_empty_id_returns_ok_false()
+    let failed = failed + test_14_failed_load_does_not_mutate_state()
+
+    let total = 14
+    let passed: Int = total - failed
+    println("=== " + int_to_str(passed) + "/" + int_to_str(total) + " passed ===")
+    return failed
+}