diff --git a/packages/opencode/src/memory/admission.ts b/packages/opencode/src/memory/admission.ts
index 1dabe4ea8d..2672ebff1a 100644
--- a/packages/opencode/src/memory/admission.ts
+++ b/packages/opencode/src/memory/admission.ts
@@ -11,6 +11,7 @@ import { MemoryConfig } from "./config"
 import { MemoryHome } from "./home"
 import { MemoryIdentityFence } from "./identity-fence"
 import { MemoryPaths } from "./paths"
+import { MemorySchema } from "./schema"
 import { MemoryStore } from "./store"
 
 const Code = Schema.Literals([
@@ -73,7 +74,7 @@ type TopicCandidate = {
 
 type ConfigCandidate = {
   readonly file: string
-  readonly config: ReturnType<typeof MemoryConfig.normalizeConfig> | undefined
+  readonly config: MemorySchema.Config | undefined
 }
 
 export const layer = Layer.effect(
@@ -228,7 +229,7 @@ export const layer = Layer.effect(
             const decoded = MemoryConfig.decodeConfig(text)
             return {
               file,
-              config: Option.isSome(decoded) ? MemoryConfig.normalizeConfig(decoded.value) : undefined,
+              config: Option.isSome(decoded) ? decoded.value : undefined,
             } satisfies ConfigCandidate
           }),
         { concurrency: 4 },
@@ -248,7 +249,7 @@ export const layer = Layer.effect(
       if (text === undefined) return true
       const decoded = MemoryConfig.decodeConfig(text)
       if (Option.isNone(decoded)) return false
-      return same(MemoryConfig.normalizeConfig(decoded.value), candidate.config)
+      return same(decoded.value, candidate.config)
     })
 
     const removeValidated = Effect.fnUntraced(function* (candidates: ReadonlyArray<ConfigCandidate>) {
diff --git a/packages/opencode/src/memory/config.ts b/packages/opencode/src/memory/config.ts
index db8162af5e..f2a7315212 100644
--- a/packages/opencode/src/memory/config.ts
+++ b/packages/opencode/src/memory/config.ts
@@ -71,10 +71,7 @@ export const layer = Layer.effect(
         yield* Effect.logWarning("memory config is invalid — ignoring", { path: found.path })
         return undefined
       }
-      if (decoded.value.topic_limit === decoded.value.topic_limit_floor) return decoded.value
-      const config = normalizeConfig(decoded.value)
-      yield* flock.withLock(MemoryFile.atomicWrite(fs, found.path, serialize(config)), writeLockKey(found.path))
-      return config
+      return decoded.value
     })
 
     const load = Effect.fn("MemoryConfig.load")(function* (projectDir: string) {
@@ -186,13 +183,8 @@ export function decodeConfig(text: string) {
   const errors: ParseError[] = []
   const value = parse(text, errors, { allowTrailingComma: true })
   if (errors.length > 0) return Option.none<MemorySchema.Config>()
-  const decoded = Schema.decodeUnknownOption(MemorySchema.Config)(value ?? {})
-  if (Option.isNone(decoded) || decoded.value.topic_limit < decoded.value.topic_limit_floor)
-    return Option.none<MemorySchema.Config>()
-  return decoded
-}
-
-export function normalizeConfig(config: MemorySchema.Config) {
-  if (config.topic_limit === config.topic_limit_floor) return config
-  return MemorySchema.updateConfig(config, { topic_limit_floor: config.topic_limit })
+  // Legacy files may still carry the removed topic_limit_floor knob — Schema
+  // Struct decoding tolerates the extra property, so such files stay valid
+  // and the dead value is simply dropped on the next write.
+  return Schema.decodeUnknownOption(MemorySchema.Config)(value ?? {})
 }
diff --git a/packages/opencode/src/memory/memory.ts b/packages/opencode/src/memory/memory.ts
index 6aa9e9b12e..6e081178ee 100644
--- a/packages/opencode/src/memory/memory.ts
+++ b/packages/opencode/src/memory/memory.ts
@@ -130,7 +130,6 @@ export const layer: Layer.Layer<
         enabled: true,
         model: selected,
         topic_limit: 10,
-        topic_limit_floor: 10,
         turn_interval: 5,
         injection: {
           max_topics: MemorySchema.MAX_INJECTION_TOPICS,
diff --git a/packages/opencode/src/memory/schema.ts b/packages/opencode/src/memory/schema.ts
index cab3802971..1dfc95d6b4 100644
--- a/packages/opencode/src/memory/schema.ts
+++ b/packages/opencode/src/memory/schema.ts
@@ -37,10 +37,6 @@ export class Config extends Schema.Class<Config>("MemoryConfig")({
     Schema.isInt(),
     Schema.isBetween({ minimum: MIN_TOPIC_LIMIT, maximum: MAX_TOPIC_LIMIT }),
   ),
-  topic_limit_floor: Schema.Number.check(
-    Schema.isInt(),
-    Schema.isBetween({ minimum: MIN_TOPIC_LIMIT, maximum: MAX_TOPIC_LIMIT }),
-  ),
   turn_interval: Schema.Number.check(
     Schema.isInt(),
     Schema.isBetween({ minimum: MIN_TURN_INTERVAL, maximum: MAX_TURN_INTERVAL }),
@@ -50,14 +46,13 @@ export class Config extends Schema.Class<Config>("MemoryConfig")({
 
 export function updateConfig(
   config: Config,
-  updates: { enabled?: boolean; model?: string; topic_limit_floor?: number },
+  updates: { enabled?: boolean; model?: string },
 ) {
   return new Config({
     schema_version: config.schema_version,
     enabled: updates.enabled ?? config.enabled,
     model: updates.model ?? config.model,
     topic_limit: config.topic_limit,
-    topic_limit_floor: updates.topic_limit_floor ?? config.topic_limit_floor,
     turn_interval: config.turn_interval,
     injection: config.injection,
   })
diff --git a/packages/opencode/test/lib/cli-process.ts b/packages/opencode/test/lib/cli-process.ts
index c295d761f5..f5c68749ea 100644
--- a/packages/opencode/test/lib/cli-process.ts
+++ b/packages/opencode/test/lib/cli-process.ts
@@ -213,7 +213,6 @@ export function withCliFixture<A, E>(
         enabled: true,
         model: testModelID,
         topic_limit: 10,
-        topic_limit_floor: 10,
         turn_interval: 5,
         injection: { max_topics: 3, max_tokens: 1_200 },
       }),
diff --git a/packages/opencode/test/memory/config.test.ts b/packages/opencode/test/memory/config.test.ts
new file mode 100644
index 0000000000..68a6468fa6
--- /dev/null
+++ b/packages/opencode/test/memory/config.test.ts
@@ -0,0 +1,54 @@
+import { describe, expect, test } from "bun:test"
+import { decodeConfig } from "@/memory/config"
+import { MemorySchema, updateConfig } from "@/memory/schema"
+
+// memory-config-fidelity: topic_limit_floor was a dead knob — no runtime
+// consumer read it, and readConfig silently rewrote any floor ≠ limit file to
+// floor := limit on every load, overwriting explicit user values. The field
+// must be gone: legacy files carrying it still decode (extra property is
+// tolerated), and decoded/updated configs never contain it.
+
+const valid = {
+  schema_version: 1,
+  enabled: true,
+  model: "p/m",
+  topic_limit: 10,
+  turn_interval: 5,
+  injection: { max_topics: 3, max_tokens: 1200 },
+}
+
+describe("MemoryConfig decode/update — topic_limit_floor removed", () => {
+  test("legacy file with a divergent floor still decodes (field ignored)", () => {
+    const decoded = decodeConfig(JSON.stringify({ ...valid, topic_limit_floor: 30 }))
+    expect(decoded._tag).toBe("Some")
+    if (decoded._tag === "Some") {
+      expect(Object.keys(decoded.value)).not.toContain("topic_limit_floor")
+    }
+  })
+
+  test("decoded config never carries the field", () => {
+    const decoded = decodeConfig(JSON.stringify(valid))
+    expect(decoded._tag).toBe("Some")
+    if (decoded._tag === "Some") {
+      expect(Object.keys(decoded.value)).not.toContain("topic_limit_floor")
+    }
+  })
+
+  test("updateConfig output never carries the field", () => {
+    const decoded = decodeConfig(JSON.stringify(valid))
+    expect(decoded._tag).toBe("Some")
+    if (decoded._tag === "Some") {
+      const next = updateConfig(decoded.value, { enabled: false })
+      expect(Object.keys(next)).not.toContain("topic_limit_floor")
+    }
+  })
+
+  test("schema bounds for the live knobs are preserved", () => {
+    expect(decodeConfig(JSON.stringify({ ...valid, topic_limit: 9 }))._tag).toBe("None")
+    expect(decodeConfig(JSON.stringify({ ...valid, turn_interval: 0 }))._tag).toBe("None")
+    expect(decodeConfig(JSON.stringify({ ...valid, injection: { max_topics: 4, max_tokens: 1200 } }))._tag).toBe(
+      "None",
+    )
+    expect(MemorySchema.MIN_TOPIC_LIMIT).toBe(10)
+  })
+})
diff --git a/packages/opencode/test/memory/memory-admission.test.ts b/packages/opencode/test/memory/memory-admission.test.ts
index a514313c59..ab6a1f1ad3 100644
--- a/packages/opencode/test/memory/memory-admission.test.ts
+++ b/packages/opencode/test/memory/memory-admission.test.ts
@@ -23,7 +23,6 @@ const config = {
   enabled: true,
   model: "test/memory-small",
   topic_limit: 10,
-  topic_limit_floor: 10,
   turn_interval: 5,
   injection: { max_topics: 3, max_tokens: 1_200 },
 } as const
diff --git a/packages/opencode/test/memory/memory-global-identity.test.ts b/packages/opencode/test/memory/memory-global-identity.test.ts
index 687b7a416f..9d38c5672e 100644
--- a/packages/opencode/test/memory/memory-global-identity.test.ts
+++ b/packages/opencode/test/memory/memory-global-identity.test.ts
@@ -59,7 +59,6 @@ const baseConfig = {
   enabled: true,
   model: "test/memory-on",
   topic_limit: 10,
-  topic_limit_floor: 10,
   turn_interval: 5,
   injection: { max_topics: 3, max_tokens: 1_200 },
 } satisfies MemorySchema.Config
diff --git a/packages/opencode/test/memory/memory-persistence.test.ts b/packages/opencode/test/memory/memory-persistence.test.ts
index 33f1dc95e0..a1d5421e0f 100644
--- a/packages/opencode/test/memory/memory-persistence.test.ts
+++ b/packages/opencode/test/memory/memory-persistence.test.ts
@@ -29,7 +29,6 @@ const config = {
   enabled: true,
   model: "test/memory-small",
   topic_limit: 10,
-  topic_limit_floor: 10,
   turn_interval: 5,
   injection: { max_topics: 3, max_tokens: 1_200 },
 } satisfies MemorySchema.Config
diff --git a/packages/opencode/test/memory/memory.test.ts b/packages/opencode/test/memory/memory.test.ts
index 730889688b..40c0f0105b 100644
--- a/packages/opencode/test/memory/memory.test.ts
+++ b/packages/opencode/test/memory/memory.test.ts
@@ -37,7 +37,6 @@ const config = {
   enabled: true,
   model: "test/memory-small",
   topic_limit: 10,
-  topic_limit_floor: 10,
   turn_interval: 5,
   injection: { max_topics: 3, max_tokens: 1_200 },
 } satisfies MemorySchema.Config
@@ -454,10 +453,13 @@ describe("memory config and YAML store", () => {
       )
       expect(yield* memoryConfig.load(tmp)).toBeUndefined()
 
+      // topic_limit_floor was removed — legacy files still carrying it decode
+      // normally (extra property tolerated); the decoded config never has it,
+      // and load never rewrites the file.
       yield* Effect.promise(() =>
         fs.writeFile(path.join(directory, "memory.jsonc"), JSON.stringify({ ...config, topic_limit_floor: 50 })),
       )
-      expect(yield* memoryConfig.load(tmp)).toBeUndefined()
+      expect((yield* memoryConfig.load(tmp))?.config.topic_limit).toBe(10)
 
       yield* Effect.promise(() =>
         fs.writeFile(
@@ -465,7 +467,7 @@ describe("memory config and YAML store", () => {
           JSON.stringify({ ...config, topic_limit: 50, topic_limit_floor: 10 }),
         ),
       )
-      expect((yield* memoryConfig.load(tmp))?.config).toMatchObject({ topic_limit: 50, topic_limit_floor: 50 })
+      expect((yield* memoryConfig.load(tmp))?.config).toMatchObject({ topic_limit: 50 })
 
       yield* Effect.promise(() =>
         fs.writeFile(
@@ -473,7 +475,7 @@ describe("memory config and YAML store", () => {
           JSON.stringify({ ...config, topic_limit: 20, topic_limit_floor: 50 }),
         ),
       )
-      expect(yield* memoryConfig.load(tmp)).toBeUndefined()
+      expect((yield* memoryConfig.load(tmp))?.config.topic_limit).toBe(20)
     }),
   )
 
@@ -1392,7 +1394,6 @@ describe("memory bootstrap", () => {
           enabled: true,
           model: "test/small",
           topic_limit: 10,
-          topic_limit_floor: 10,
           turn_interval: 5,
           injection: { max_topics: 3, max_tokens: 1_200 },
         })
@@ -1446,7 +1447,6 @@ describe("memory bootstrap", () => {
           ...config,
           model: "test/conversation",
           topic_limit: 42,
-          topic_limit_floor: 42,
           turn_interval: 9,
         }
         const memory = yield* Memory.Service
@@ -1457,7 +1457,6 @@ describe("memory bootstrap", () => {
         expect(bootstrap.state.global).toMatchObject({
           model: "test/conversation",
           topic_limit: 42,
-          topic_limit_floor: 42,
           turn_interval: 9,
         })
         expect(bootstrap.state.modelCalls).toBe(0)
@@ -1475,7 +1474,6 @@ describe("memory bootstrap", () => {
           ...config,
           model: "removed/model",
           topic_limit: 37,
-          topic_limit_floor: 37,
           turn_interval: 7,
         }
         const memory = yield* Memory.Service
@@ -1485,7 +1483,6 @@ describe("memory bootstrap", () => {
         expect(bootstrap.state.written).toMatchObject({
           model: "test/compaction",
           topic_limit: 37,
-          topic_limit_floor: 37,
           turn_interval: 7,
         })
         expect(bootstrap.state.modelCalls).toBe(0)
@@ -1523,7 +1520,6 @@ describe("memory bootstrap", () => {
         expect(bootstrap.state.written).toMatchObject({
           model: "test/conversation",
           topic_limit: 10,
-          topic_limit_floor: 10,
           turn_interval: 5,
         })
         expect(bootstrap.state.modelCalls).toBe(0)
@@ -1544,7 +1540,6 @@ describe("memory bootstrap", () => {
           ...config,
           model: "removed/model",
           topic_limit: 37,
-          topic_limit_floor: 37,
           turn_interval: 7,
         }
         const memory = yield* Memory.Service
@@ -1561,7 +1556,6 @@ describe("memory bootstrap", () => {
         expect(bootstrap.state.written).toMatchObject({
           model: "test/conversation",
           topic_limit: 37,
-          topic_limit_floor: 37,
           turn_interval: 7,
         })
         expect(bootstrap.state.modelCalls).toBe(0)
@@ -1601,7 +1595,6 @@ describe("memory bootstrap", () => {
         expect(bootstrap.state.written).toMatchObject({
           model: "test/conversation",
           topic_limit: 10,
-          topic_limit_floor: 10,
           turn_interval: 5,
         })
         expect(bootstrap.state.modelCalls).toBe(0)
diff --git a/packages/opencode/test/project/worktree-remove.test.ts b/packages/opencode/test/project/worktree-remove.test.ts
index 503e6860aa..44a0bf7470 100644
--- a/packages/opencode/test/project/worktree-remove.test.ts
+++ b/packages/opencode/test/project/worktree-remove.test.ts
@@ -159,7 +159,6 @@ describe("Worktree.remove", () => {
       enabled,
       model,
       topic_limit: 10,
-      topic_limit_floor: 10,
       turn_interval: 5,
       injection: { max_topics: 3, max_tokens: 1_200 },
     })