diff --git a/src/resources/extensions/gsd/model-cost-table.ts b/src/resources/extensions/gsd/model-cost-table.ts
index 82be7930d..4c4ebc81c 100644
--- a/src/resources/extensions/gsd/model-cost-table.ts
+++ b/src/resources/extensions/gsd/model-cost-table.ts
@@ -33,10 +33,29 @@ export const BUNDLED_COST_TABLE: ModelCostEntry[] = [
   // OpenAI
   { id: "gpt-4o", inputPer1k: 0.0025, outputPer1k: 0.01, updatedAt: "2025-03-15" },
   { id: "gpt-4o-mini", inputPer1k: 0.00015, outputPer1k: 0.0006, updatedAt: "2025-03-15" },
+  { id: "gpt-4.1", inputPer1k: 0.002, outputPer1k: 0.008, updatedAt: "2026-03-29" },
+  { id: "gpt-4.1-mini", inputPer1k: 0.0004, outputPer1k: 0.0016, updatedAt: "2026-03-29" },
+  { id: "gpt-4.1-nano", inputPer1k: 0.0001, outputPer1k: 0.0004, updatedAt: "2026-03-29" },
+  { id: "gpt-5", inputPer1k: 0.01, outputPer1k: 0.04, updatedAt: "2026-03-29" },
+  { id: "gpt-5-mini", inputPer1k: 0.0003, outputPer1k: 0.0012, updatedAt: "2026-03-29" },
+  { id: "gpt-5-nano", inputPer1k: 0.0001, outputPer1k: 0.0004, updatedAt: "2026-03-29" },
+  { id: "gpt-5-pro", inputPer1k: 0.015, outputPer1k: 0.06, updatedAt: "2026-03-29" },
   { id: "o1", inputPer1k: 0.015, outputPer1k: 0.06, updatedAt: "2025-03-15" },
   { id: "o3", inputPer1k: 0.015, outputPer1k: 0.06, updatedAt: "2025-03-15" },
+  { id: "o4-mini", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+  { id: "o4-mini-deep-research", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
   { id: "gpt-4-turbo", inputPer1k: 0.01, outputPer1k: 0.03, updatedAt: "2025-03-15" },
 
+  // OpenAI Codex
+  { id: "gpt-5.1", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+  { id: "gpt-5.1-codex-max", inputPer1k: 0.003, outputPer1k: 0.012, updatedAt: "2026-03-29" },
+  { id: "gpt-5.1-codex-mini", inputPer1k: 0.0003, outputPer1k: 0.0012, updatedAt: "2026-03-29" },
+  { id: "gpt-5.2", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+  { id: "gpt-5.2-codex", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+  { id: "gpt-5.3-codex", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+  { id: "gpt-5.3-codex-spark", inputPer1k: 0.0003, outputPer1k: 0.0012, updatedAt: "2026-03-29" },
+  { id: "gpt-5.4", inputPer1k: 0.005, outputPer1k: 0.02, updatedAt: "2026-03-29" },
+
   // Google
   { id: "gemini-2.0-flash", inputPer1k: 0.0001, outputPer1k: 0.0004, updatedAt: "2025-03-15" },
   { id: "gemini-flash-2.0", inputPer1k: 0.0001, outputPer1k: 0.0004, updatedAt: "2025-03-15" },
diff --git a/src/resources/extensions/gsd/model-router.ts b/src/resources/extensions/gsd/model-router.ts
index fe8bdf0a5..ebc110b6f 100644
--- a/src/resources/extensions/gsd/model-router.ts
+++ b/src/resources/extensions/gsd/model-router.ts
@@ -44,6 +44,12 @@ const MODEL_CAPABILITY_TIER: Record<string, ComplexityTier> = {
   "claude-3-5-haiku-latest": "light",
   "claude-3-haiku-20240307": "light",
   "gpt-4o-mini": "light",
+  "gpt-4.1-mini": "light",
+  "gpt-4.1-nano": "light",
+  "gpt-5-mini": "light",
+  "gpt-5-nano": "light",
+  "gpt-5.1-codex-mini": "light",
+  "gpt-5.3-codex-spark": "light",
   "gemini-2.0-flash": "light",
   "gemini-flash-2.0": "light",
 
@@ -52,6 +58,8 @@ const MODEL_CAPABILITY_TIER: Record<string, ComplexityTier> = {
   "claude-sonnet-4-5-20250514": "standard",
   "claude-3-5-sonnet-latest": "standard",
   "gpt-4o": "standard",
+  "gpt-4.1": "standard",
+  "gpt-5.1-codex-max": "standard",
   "gemini-2.5-pro": "standard",
   "deepseek-chat": "standard",
 
@@ -59,8 +67,17 @@ const MODEL_CAPABILITY_TIER: Record<string, ComplexityTier> = {
   "claude-opus-4-6": "heavy",
   "claude-3-opus-latest": "heavy",
   "gpt-4-turbo": "heavy",
+  "gpt-5": "heavy",
+  "gpt-5-pro": "heavy",
+  "gpt-5.1": "heavy",
+  "gpt-5.2": "heavy",
+  "gpt-5.2-codex": "heavy",
+  "gpt-5.3-codex": "heavy",
+  "gpt-5.4": "heavy",
   "o1": "heavy",
   "o3": "heavy",
+  "o4-mini": "heavy",
+  "o4-mini-deep-research": "heavy",
 };
 
 // ─── Cost Table (per 1K input tokens, approximate USD) ───────────────────────
@@ -75,6 +92,23 @@ const MODEL_COST_PER_1K_INPUT: Record<string, number> = {
   "claude-opus-4-6": 0.015,
   "gpt-4o-mini": 0.00015,
   "gpt-4o": 0.0025,
+  "gpt-4.1": 0.002,
+  "gpt-4.1-mini": 0.0004,
+  "gpt-4.1-nano": 0.0001,
+  "gpt-5": 0.01,
+  "gpt-5-mini": 0.0003,
+  "gpt-5-nano": 0.0001,
+  "gpt-5-pro": 0.015,
+  "gpt-5.1": 0.005,
+  "gpt-5.1-codex-max": 0.003,
+  "gpt-5.1-codex-mini": 0.0003,
+  "gpt-5.2": 0.005,
+  "gpt-5.2-codex": 0.005,
+  "gpt-5.3-codex": 0.005,
+  "gpt-5.3-codex-spark": 0.0003,
+  "gpt-5.4": 0.005,
+  "o4-mini": 0.005,
+  "o4-mini-deep-research": 0.005,
   "gemini-2.0-flash": 0.0001,
   "gemini-2.5-pro": 0.00125,
   "deepseek-chat": 0.00014,
diff --git a/src/resources/extensions/gsd/tests/model-cost-table.test.ts b/src/resources/extensions/gsd/tests/model-cost-table.test.ts
index 98906c083..4ab8381f0 100644
--- a/src/resources/extensions/gsd/tests/model-cost-table.test.ts
+++ b/src/resources/extensions/gsd/tests/model-cost-table.test.ts
@@ -67,3 +67,37 @@ test("all cost table entries have valid data", () => {
     assert.ok(entry.updatedAt, `${entry.id} missing updatedAt`);
   }
 });
+
+// ─── #2885: openai-codex and modern OpenAI models in cost table ──────────────
+
+test("#2885: cost table includes openai-codex provider models", () => {
+  const ids = BUNDLED_COST_TABLE.map(e => e.id);
+  const codexModels = [
+    "gpt-5.1", "gpt-5.1-codex-max", "gpt-5.1-codex-mini",
+    "gpt-5.2", "gpt-5.2-codex", "gpt-5.3-codex", "gpt-5.3-codex-spark", "gpt-5.4",
+  ];
+  for (const model of codexModels) {
+    assert.ok(ids.includes(model), `cost table should include openai-codex model "${model}"`);
+  }
+});
+
+test("#2885: cost table includes modern OpenAI models", () => {
+  const ids = BUNDLED_COST_TABLE.map(e => e.id);
+  const newModels = [
+    "o4-mini", "o4-mini-deep-research",
+    "gpt-4.1", "gpt-4.1-mini", "gpt-4.1-nano",
+    "gpt-5", "gpt-5-mini", "gpt-5-nano", "gpt-5-pro",
+  ];
+  for (const model of newModels) {
+    assert.ok(ids.includes(model), `cost table should include modern OpenAI model "${model}"`);
+  }
+});
+
+test("#2885: lookupModelCost returns costs for new models (not 999 fallback)", () => {
+  const newModels = ["o4-mini", "gpt-4.1", "gpt-5", "gpt-5.4", "gpt-5.1-codex-mini"];
+  for (const model of newModels) {
+    const entry = lookupModelCost(model);
+    assert.ok(entry, `lookupModelCost should find "${model}"`);
+    assert.ok(entry.inputPer1k < 999, `${model} should have a real cost, not the 999 fallback`);
+  }
+});
diff --git a/src/resources/extensions/gsd/tests/model-router.test.ts b/src/resources/extensions/gsd/tests/model-router.test.ts
index b22fce7fd..fb1128eb5 100644
--- a/src/resources/extensions/gsd/tests/model-router.test.ts
+++ b/src/resources/extensions/gsd/tests/model-router.test.ts
@@ -172,11 +172,11 @@ test("#2192: unknown model is not downgraded — respects user config", () => {
   const config = { ...defaultRoutingConfig(), enabled: true };
   const result = resolveModelForComplexity(
     makeClassification("light"),
-    { primary: "gpt-5.4", fallbacks: [] },
+    { primary: "some-future-unknown-model-v9", fallbacks: [] },
     config,
-    ["gpt-5.4", ...AVAILABLE_MODELS],
+    ["some-future-unknown-model-v9", ...AVAILABLE_MODELS],
   );
-  assert.equal(result.modelId, "gpt-5.4", "unknown model should be used as-is");
+  assert.equal(result.modelId, "some-future-unknown-model-v9", "unknown model should be used as-is");
   assert.equal(result.wasDowngraded, false, "should not be downgraded");
   assert.ok(result.reason.includes("not in the known tier map"), "reason should explain why");
 });
@@ -205,3 +205,68 @@ test("#2192: known model is still downgraded normally", () => {
   assert.equal(result.wasDowngraded, true, "known heavy model should still be downgraded for light tasks");
   assert.notEqual(result.modelId, "claude-opus-4-6");
 });
+
+// ─── #2885: openai-codex and modern OpenAI models in tier map ────────────────
+
+test("#2885: openai-codex light-tier models are recognized", () => {
+  const config = { ...defaultRoutingConfig(), enabled: true };
+  const lightModels = ["gpt-4.1-mini", "gpt-4.1-nano", "gpt-5-mini", "gpt-5-nano", "gpt-5.1-codex-mini", "gpt-5.3-codex-spark"];
+  for (const model of lightModels) {
+    const result = resolveModelForComplexity(
+      makeClassification("light"),
+      { primary: model, fallbacks: [] },
+      config,
+      [model, ...AVAILABLE_MODELS],
+    );
+    // Model is known AND light-tier, so requesting light should NOT downgrade
+    assert.equal(result.wasDowngraded, false, `${model} should be known as light tier (wasDowngraded)`);
+    assert.equal(result.modelId, model, `${model} should be returned as-is for light tier`);
+    // Verify it IS known (not hitting the unknown-model bail-out)
+    assert.ok(!result.reason.includes("not in the known tier map"), `${model} should be in the known tier map`);
+  }
+});
+
+test("#2885: openai-codex standard-tier models are recognized", () => {
+  const config = { ...defaultRoutingConfig(), enabled: true };
+  const standardModels = ["gpt-4.1", "gpt-5.1-codex-max"];
+  for (const model of standardModels) {
+    const result = resolveModelForComplexity(
+      makeClassification("standard"),
+      { primary: model, fallbacks: [] },
+      config,
+      [model, ...AVAILABLE_MODELS],
+    );
+    assert.equal(result.wasDowngraded, false, `${model} should be known as standard tier`);
+    assert.equal(result.modelId, model, `${model} should be returned as-is for standard tier`);
+    assert.ok(!result.reason.includes("not in the known tier map"), `${model} should be in the known tier map`);
+  }
+});
+
+test("#2885: openai-codex heavy-tier models are recognized", () => {
+  const config = { ...defaultRoutingConfig(), enabled: true };
+  const heavyModels = ["gpt-5", "gpt-5-pro", "gpt-5.1", "gpt-5.2", "gpt-5.2-codex", "gpt-5.3-codex", "gpt-5.4", "o4-mini", "o4-mini-deep-research"];
+  for (const model of heavyModels) {
+    const result = resolveModelForComplexity(
+      makeClassification("heavy"),
+      { primary: model, fallbacks: [] },
+      config,
+      [model, ...AVAILABLE_MODELS],
+    );
+    assert.equal(result.wasDowngraded, false, `${model} should be known as heavy tier`);
+    assert.equal(result.modelId, model, `${model} should be returned as-is for heavy tier`);
+    assert.ok(!result.reason.includes("not in the known tier map"), `${model} should be in the known tier map`);
+  }
+});
+
+test("#2885: heavy openai-codex model downgrades to light for light task", () => {
+  const config = { ...defaultRoutingConfig(), enabled: true };
+  const result = resolveModelForComplexity(
+    makeClassification("light"),
+    { primary: "gpt-5.4", fallbacks: [] },
+    config,
+    ["gpt-5.4", "gpt-4.1-nano", ...AVAILABLE_MODELS],
+  );
+  assert.equal(result.wasDowngraded, true, "heavy model should downgrade for light task");
+  // Should pick a light-tier model
+  assert.notEqual(result.modelId, "gpt-5.4", "should not use the heavy model for light task");
+});