diff --git a/docs/cli/me-memory.md b/docs/cli/me-memory.md
index d30e2f7..3b0ca3b 100644
--- a/docs/cli/me-memory.md
+++ b/docs/cli/me-memory.md
@@ -81,6 +81,7 @@ me memory search [query] [options]
 | `--meta <json>` | Metadata filter as JSON. |
 | `--limit <n>` | Max results (default: 10). |
 | `--candidate-limit <n>` | Pre-RRF candidate pool size. |
+| `--semantic-threshold <n>` | Minimum semantic similarity score, 0-1. |
 | `--temporal-contains <ts>` | Memory must contain this point in time. |
 | `--temporal-overlaps <range>` | Memory must overlap this range (`start,end`). |
 | `--temporal-within <range>` | Memory must be within this range (`start,end`). |
diff --git a/docs/cli/me-serve.md b/docs/cli/me-serve.md
index 4bc1fc2..5463002 100644
--- a/docs/cli/me-serve.md
+++ b/docs/cli/me-serve.md
@@ -54,7 +54,7 @@ The UI talks to whichever engine is active for the current server — same resol
 ```
 
 - **Tree** (left): ltree paths as collapsible nodes, memories as leaves. Right-click a node for a context menu (delete memory / delete subtree).
-- **Search** (top): simple hybrid search by default; flip to Advanced for every field accepted by `memory.search` (semantic, fulltext, grep, tree, meta, temporal, limit, candidateLimit, weights, orderBy).
+- **Search** (top): simple hybrid search by default; flip to Advanced for every field accepted by `memory.search` (semantic, fulltext, grep, tree, meta, temporal, limit, candidateLimit, semanticThreshold, weights, orderBy).
 - **Viewer / Editor** (right): rendered Markdown with syntax highlighting, or the Monaco editor with YAML frontmatter + body. The copy button copies the Markdown source with frontmatter. Save is disabled until you make a valid change. The read-only metadata panel sits below.
 - **URL state**: filter fields and the selected memory id are reflected in the URL, so any view can be shared or bookmarked.
 
diff --git a/docs/mcp/me_memory_search.md b/docs/mcp/me_memory_search.md
index bad9858..2197ace 100644
--- a/docs/mcp/me_memory_search.md
+++ b/docs/mcp/me_memory_search.md
@@ -16,6 +16,7 @@ Supports three search modes: **semantic** (meaning-based), **fulltext** (keyword
 | `temporal` | `object \| null` | no | Temporal filter. Omit or pass `null` to skip. |
 | `weights` | `object \| null` | no | Weights for hybrid search ranking. Omit or pass `null` for defaults. |
 | `candidateLimit` | `integer \| null` | no | Candidates per search mode before RRF fusion. Omit or pass `null` for default (30). |
+| `semanticThreshold` | `number \| null` | no | Minimum semantic similarity score (0-1) for vector candidates. Omit or pass `null` to skip. |
 | `limit` | `integer \| null` | no | Maximum number of results. Omit or pass `null` for default (10). Max: 1000. |
 | `order_by` | `string \| null` | no | Sort direction for filter-only searches: `"asc"` or `"desc"`. Default: `"desc"`. Omit or pass `null` for default. |
 
@@ -83,7 +84,8 @@ See [Tree filter syntax](../concepts.md#tree-filter-syntax) for the full referen
 ```json
 {
   "semantic": "how does authentication work",
-  "limit": 10
+  "limit": 10,
+  "semanticThreshold": 0.7
 }
 ```
 
diff --git a/docs/typescript-client.md b/docs/typescript-client.md
index ebc7fd2..376cbf8 100644
--- a/docs/typescript-client.md
+++ b/docs/typescript-client.md
@@ -155,6 +155,7 @@ const { results, total } = await me.memory.search({
   // Tuning
   limit: 10,                           // max results (1-1000)
   candidateLimit: 30,                  // candidates per mode before RRF fusion
+  semanticThreshold: 0.7,              // optional min semantic score (0-1)
   weights: { semantic: 0.7, fulltext: 0.3 },
   orderBy: "desc",                     // for filter-only queries (no search)
 });
diff --git a/packages/cli/commands/memory.ts b/packages/cli/commands/memory.ts
index c9e6cf4..6d0405f 100644
--- a/packages/cli/commands/memory.ts
+++ b/packages/cli/commands/memory.ts
@@ -220,6 +220,7 @@ function createMemorySearchCommand(): Command {
     .option("--meta <json>", "metadata filter (JSON)")
     .option("--limit <n>", "max results", "10")
     .option("--candidate-limit <n>", "pre-RRF candidate pool size")
+    .option("--semantic-threshold <n>", "minimum semantic score (0-1)")
     .option("--temporal-contains <ts>", "memory must contain this point")
     .option("--temporal-overlaps <range>", "memory must overlap (start,end)")
     .option("--temporal-within <range>", "memory must be within (start,end)")
@@ -322,6 +323,8 @@ function createMemorySearchCommand(): Command {
         if (weights) params.weights = weights;
         if (opts.candidateLimit)
           params.candidateLimit = Number.parseInt(opts.candidateLimit, 10);
+        if (opts.semanticThreshold)
+          params.semanticThreshold = Number.parseFloat(opts.semanticThreshold);
         if (opts.orderBy) params.orderBy = opts.orderBy;
 
         const result = await engine.memory.search(
diff --git a/packages/cli/mcp/server.ts b/packages/cli/mcp/server.ts
index bdf5907..c9ea69b 100644
--- a/packages/cli/mcp/server.ts
+++ b/packages/cli/mcp/server.ts
@@ -204,6 +204,15 @@ Docs: ${docUrl("me_memory_search")}`,
           .describe(
             "Candidates per search mode before RRF fusion (0 = default 30)",
           ),
+        semanticThreshold: z
+          .number()
+          .min(0)
+          .max(1)
+          .optional()
+          .nullable()
+          .describe(
+            "Minimum semantic similarity score (0-1) for vector candidates",
+          ),
         limit: z
           .number()
           .int()
@@ -250,6 +259,7 @@ Docs: ${docUrl("me_memory_search")}`,
             ? args.candidateLimit
             : undefined,
         limit: args.limit && args.limit > 0 ? args.limit : undefined,
+        semanticThreshold: args.semanticThreshold ?? undefined,
         orderBy:
           (args.order_by as "asc" | "desc" | null | undefined) ?? undefined,
       });
diff --git a/packages/engine/ops/memory.ts b/packages/engine/ops/memory.ts
index 896d9c0..ad13142 100644
--- a/packages/engine/ops/memory.ts
+++ b/packages/engine/ops/memory.ts
@@ -316,10 +316,18 @@ async function buildSemanticQuery(
   params: FilterParams & {
     embedding: number[];
     limit: number;
+    semanticThreshold?: number;
   },
 ): Promise<SearchRow[]> {
-  const { clauses, values } = buildCommonFilters(params, 2); // $1=embedding, $2=limit
-
+  const hasSemanticThreshold = typeof params.semanticThreshold === "number";
+  const { clauses, values } = buildCommonFilters(
+    params,
+    hasSemanticThreshold ? 3 : 2,
+  ); // $1=embedding, $2=limit, optional $3=semanticThreshold
+
+  const semanticThresholdClause = hasSemanticThreshold
+    ? "AND (1 - (embedding <=> $1::halfvec)) >= $3"
+    : "AND (embedding <=> $1::halfvec) < 1.0";
   const whereClause = clauses.length > 0 ? `AND ${clauses.join(" AND ")}` : "";
 
   // Format embedding as PostgreSQL array literal
@@ -333,7 +341,7 @@ async function buildSemanticQuery(
       (1 - (embedding <=> $1::halfvec)) as score
     FROM ${schema}.memory
     WHERE embedding IS NOT NULL
-      AND (embedding <=> $1::halfvec) < 1.0
+      ${semanticThresholdClause}
       ${whereClause}
     ORDER BY score DESC, created_at DESC
     LIMIT $2
@@ -342,6 +350,7 @@ async function buildSemanticQuery(
   return sql.unsafe<SearchRow[]>(query, [
     embeddingLiteral,
     params.limit,
+    ...(hasSemanticThreshold ? [params.semanticThreshold] : []),
     ...values,
   ]);
 }
@@ -626,6 +635,7 @@ export function memoryOps(ctx: OpsContext) {
         temporal,
         limit = 10,
         candidateLimit = 30,
+        semanticThreshold,
         weights = { fulltext: 1.0, semantic: 1.0 },
         orderBy = "desc",
       } = params;
@@ -651,6 +661,7 @@ export function memoryOps(ctx: OpsContext) {
               tree,
               temporal,
               limit: candidateLimit,
+              semanticThreshold,
             }),
           ]);
 
@@ -689,6 +700,7 @@ export function memoryOps(ctx: OpsContext) {
             tree,
             temporal,
             limit,
+            semanticThreshold,
           });
           results = rows.map(rowToSearchResult);
         } else {
diff --git a/packages/engine/types.ts b/packages/engine/types.ts
index 3071c29..66bb0cf 100644
--- a/packages/engine/types.ts
+++ b/packages/engine/types.ts
@@ -210,6 +210,8 @@ export interface SearchParams {
   limit?: number;
   /** Candidates per search mode before RRF fusion */
   candidateLimit?: number;
+  /** Minimum semantic similarity score (0-1) for vector candidates */
+  semanticThreshold?: number;
   /** Weights for hybrid search */
   weights?: SearchWeights;
   /** Sort direction for filter-only searches */
diff --git a/packages/protocol/engine/memory.ts b/packages/protocol/engine/memory.ts
index 0be6535..da65f12 100644
--- a/packages/protocol/engine/memory.ts
+++ b/packages/protocol/engine/memory.ts
@@ -92,6 +92,7 @@ export const memorySearchParams = z.object({
   temporal: temporalFilterSchema.optional().nullable(),
   limit: z.number().int().min(1).max(1000).optional(),
   candidateLimit: z.number().int().min(1).max(1000).optional(),
+  semanticThreshold: z.number().min(0).max(1).optional().nullable(),
   weights: searchWeightsSchema.optional().nullable(),
   orderBy: z.enum(["asc", "desc"]).optional(),
 });
diff --git a/packages/server/rpc/engine/memory.ts b/packages/server/rpc/engine/memory.ts
index bf9b939..c877b34 100644
--- a/packages/server/rpc/engine/memory.ts
+++ b/packages/server/rpc/engine/memory.ts
@@ -318,6 +318,7 @@ async function memorySearch(
     temporal: parseTemporalFilter(params.temporal),
     limit: params.limit,
     candidateLimit: params.candidateLimit,
+    semanticThreshold: params.semanticThreshold ?? undefined,
     weights: params.weights ?? undefined,
     orderBy: params.orderBy,
   });
diff --git a/packages/web/src/api/queries.ts b/packages/web/src/api/queries.ts
index 7fba9ca..c3e2e99 100644
--- a/packages/web/src/api/queries.ts
+++ b/packages/web/src/api/queries.ts
@@ -171,6 +171,9 @@ export function normalizeSearchParams(
   if (typeof params.candidateLimit === "number") {
     out.candidateLimit = params.candidateLimit;
   }
+  if (typeof params.semanticThreshold === "number") {
+    out.semanticThreshold = params.semanticThreshold;
+  }
 
   const hasAnyFilter =
     out.semantic !== undefined ||
diff --git a/packages/web/src/components/search/AdvancedSearchPanel.tsx b/packages/web/src/components/search/AdvancedSearchPanel.tsx
index bd90bee..86735dc 100644
--- a/packages/web/src/components/search/AdvancedSearchPanel.tsx
+++ b/packages/web/src/components/search/AdvancedSearchPanel.tsx
@@ -121,7 +121,7 @@ export function AdvancedSearchPanel() {
         <NumberInput
           value={advanced.limit}
           onChange={(v) => setAdvanced({ limit: v })}
-          placeholder="1000 (default)"
+          placeholder="50 semantic-only; otherwise 1000"
           min={1}
           max={1000}
         />
@@ -137,6 +137,20 @@ export function AdvancedSearchPanel() {
         />
       </Field>
 
+      <Field label="semantic threshold (0–1)">
+        <NumberInput
+          value={advanced.semanticThreshold}
+          onChange={(v) => setAdvanced({ semanticThreshold: v })}
+          placeholder="optional min score"
+          step="0.01"
+          min={0}
+          max={1}
+        />
+        <p className="mt-1 text-xs text-slate-500">
+          Filters semantic candidates before ranking. Higher is stricter.
+        </p>
+      </Field>
+
       <Field label="weights.semantic (0–1)">
         <NumberInput
           value={advanced.weightsSemantic}
diff --git a/packages/web/src/lib/url-state.test.ts b/packages/web/src/lib/url-state.test.ts
index 72581eb..00cf187 100644
--- a/packages/web/src/lib/url-state.test.ts
+++ b/packages/web/src/lib/url-state.test.ts
@@ -45,6 +45,7 @@ describe("encode/decode round-trip", () => {
         },
         limit: "500",
         candidateLimit: "200",
+        semanticThreshold: "0.72",
         weightsSemantic: "0.7",
         weightsFulltext: "0.3",
         orderBy: "desc",
diff --git a/packages/web/src/lib/url-state.ts b/packages/web/src/lib/url-state.ts
index 326907b..2b2b6f7 100644
--- a/packages/web/src/lib/url-state.ts
+++ b/packages/web/src/lib/url-state.ts
@@ -42,6 +42,7 @@ export function encodeUrlState(
     if (a.temporal.end) p.set("temporal_end", a.temporal.end);
     if (a.limit) p.set("limit", a.limit);
     if (a.candidateLimit) p.set("candidate_limit", a.candidateLimit);
+    if (a.semanticThreshold) p.set("semantic_threshold", a.semanticThreshold);
     if (a.weightsSemantic) p.set("weights_semantic", a.weightsSemantic);
     if (a.weightsFulltext) p.set("weights_fulltext", a.weightsFulltext);
     if (a.orderBy) p.set("order_by", a.orderBy);
@@ -80,6 +81,7 @@ export function decodeUrlState(search: string): {
     },
     limit: p.get("limit") ?? "",
     candidateLimit: p.get("candidate_limit") ?? "",
+    semanticThreshold: p.get("semantic_threshold") ?? "",
     weightsSemantic: p.get("weights_semantic") ?? "",
     weightsFulltext: p.get("weights_fulltext") ?? "",
     orderBy: coerceOrderBy(p.get("order_by")),
diff --git a/packages/web/src/store/filter.test.ts b/packages/web/src/store/filter.test.ts
index 10bfbe8..05b6d6d 100644
--- a/packages/web/src/store/filter.test.ts
+++ b/packages/web/src/store/filter.test.ts
@@ -99,6 +99,31 @@ describe("mergeMetaJsonFilter", () => {
 });
 
 describe("selectSearchParams", () => {
+  test("uses a smaller default limit for advanced semantic-only search", () => {
+    expect(selectSearchParams(withAdvanced({ semantic: "hello" })).limit).toBe(
+      50,
+    );
+  });
+
+  test("preserves explicit limits for advanced semantic-only search", () => {
+    expect(
+      selectSearchParams(withAdvanced({ semantic: "hello", limit: "10" }))
+        .limit,
+    ).toBe(10);
+  });
+
+  test("passes semantic threshold through only when semantic search is set", () => {
+    expect(
+      selectSearchParams(
+        withAdvanced({ semantic: "hello", semanticThreshold: "0.72" }),
+      ).semanticThreshold,
+    ).toBe(0.72);
+    expect(
+      selectSearchParams(withAdvanced({ semanticThreshold: "0.72" }))
+        .semanticThreshold,
+    ).toBeUndefined();
+  });
+
   test("converts datetime-local temporal contains filters to offset ISO datetimes", () => {
     const start = "2026-01-01T12:34:56";
 
@@ -159,6 +184,7 @@ describe("summarizeFilter (advanced mode)", () => {
         tree: "work.*",
         limit: "50",
         candidateLimit: "25",
+        semanticThreshold: "0.72",
         orderBy: "asc",
       }),
     );
@@ -169,6 +195,7 @@ describe("summarizeFilter (advanced mode)", () => {
       `tree: work.*`,
       `limit: 50`,
       `candidateLimit: 25`,
+      `semanticThreshold: 0.72`,
       `order: asc`,
     ]);
   });
diff --git a/packages/web/src/store/filter.ts b/packages/web/src/store/filter.ts
index 994881a..946f79c 100644
--- a/packages/web/src/store/filter.ts
+++ b/packages/web/src/store/filter.ts
@@ -33,9 +33,11 @@ export interface AdvancedFilter {
     start: string;
     end: string;
   };
-  /** Empty string means "use default (1000)". */
+  /** Empty string means "use default (1000, or 50 for semantic-only)". */
   limit: string;
   candidateLimit: string;
+  /** Minimum vector similarity score (0-1) for semantic candidates. */
+  semanticThreshold: string;
   weightsSemantic: string;
   weightsFulltext: string;
   orderBy: "" | "asc" | "desc";
@@ -67,6 +69,7 @@ export const EMPTY_ADVANCED: AdvancedFilter = {
   temporal: { mode: "overlaps", start: "", end: "" },
   limit: "",
   candidateLimit: "",
+  semanticThreshold: "",
   weightsSemantic: "",
   weightsFulltext: "",
   orderBy: "",
@@ -147,11 +150,20 @@ export function selectSearchParams(state: FilterState): MemorySearchParams {
   if (temporal) params.temporal = temporal;
 
   const limit = parseIntOrUndef(a.limit);
-  if (limit !== undefined) params.limit = limit;
+  if (limit !== undefined) {
+    params.limit = limit;
+  } else if (params.semantic && !params.fulltext) {
+    params.limit = 50;
+  }
 
   const candidateLimit = parseIntOrUndef(a.candidateLimit);
   if (candidateLimit !== undefined) params.candidateLimit = candidateLimit;
 
+  const semanticThreshold = parseFloatInRangeOrUndef(a.semanticThreshold, 0, 1);
+  if (semanticThreshold !== undefined && params.semantic) {
+    params.semanticThreshold = semanticThreshold;
+  }
+
   const ws = parseFloatOrUndef(a.weightsSemantic);
   const wf = parseFloatOrUndef(a.weightsFulltext);
   if (ws !== undefined || wf !== undefined) {
@@ -197,6 +209,16 @@ function parseFloatOrUndef(s: string): number | undefined {
   return Number.isFinite(n) ? n : undefined;
 }
 
+function parseFloatInRangeOrUndef(
+  s: string,
+  min: number,
+  max: number,
+): number | undefined {
+  const n = parseFloatOrUndef(s);
+  if (n === undefined) return undefined;
+  return n >= min && n <= max ? n : undefined;
+}
+
 /**
  * Human-readable summary of the active filter, used by the collapsed
  * search bar.
@@ -238,6 +260,9 @@ export function summarizeFilter(state: FilterState): {
   if (a.candidateLimit.trim()) {
     chips.push(`candidateLimit: ${a.candidateLimit.trim()}`);
   }
+  if (a.semantic.trim() && a.semanticThreshold.trim()) {
+    chips.push(`semanticThreshold: ${a.semanticThreshold.trim()}`);
+  }
 
   const ws = a.weightsSemantic.trim();
   const wf = a.weightsFulltext.trim();