diff --git a/Dockerfile b/Dockerfile
index 1a3e996b99b3..f1efc2fc0354 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -230,6 +230,6 @@ RUN --mount=type=cache,id=apt-cache,target=/var/cache/apt,sharing=locked \
 
 # Install CLI tools globally. Separate layer from apt for better cache reuse.
 RUN --mount=type=cache,id=npm-cache,target=/root/.npm \
-  npm install -g --no-audit --no-fund @openai/codex@0.156.1 @anthropic-ai/claude-code droid openclaw@latest
+  npm install -g --no-audit --no-fund @openai/codex@0.159.2 @anthropic-ai/claude-code droid openclaw@latest
 
 USER node
diff --git a/changelog.d/features/15171-stable-gpt61-sol.md b/changelog.d/features/15171-stable-gpt61-sol.md
new file mode 100644
index 000000000000..d54cef599d21
--- /dev/null
+++ b/changelog.d/features/15171-stable-gpt61-sol.md
@@ -0,0 +1 @@
+- **feat(codex):** Add GPT-6.1 Sol to the stable fork's OpenAI and Codex catalogs, preserve Max/Ultra routing and tool calls, accept Responses model imports, and align the Codex client profile and optional Docker CLI at 0.159.2. Include Standard short-context price estimates and the purchased-credit Fast multiplier; adapt upstream [#15171](https://github.com/diegosouzapw/OmniRoute/pull/15171) and [#15158](https://github.com/diegosouzapw/OmniRoute/pull/15158) — thanks @xiaoyaner0201 and @HouMinXi.
diff --git a/open-sse/config/codexClient.ts b/open-sse/config/codexClient.ts
index 176278679616..7398df724aec 100644
--- a/open-sse/config/codexClient.ts
+++ b/open-sse/config/codexClient.ts
@@ -1,8 +1,8 @@
 // Codex's OAuth backend gates newer models by client version: GPT-6 Astra rejects
 // older clients with "requires a newer version of Codex" (upstream issue #12761).
 // Keep this in lockstep with CODEX_CLI_PROFILE in src/shared/constants/clientIdentityProfiles.ts.
-// https://github.com/openai/codex/releases/tag/rust-v0.156.1
-const DEFAULT_CODEX_CLIENT_VERSION = "0.156.1";
+// https://github.com/openai/codex/releases/tag/rust-v0.159.2
+const DEFAULT_CODEX_CLIENT_VERSION = "0.159.2";
 const DEFAULT_CODEX_USER_AGENT_PLATFORM = "Windows 10.0.26200";
 const DEFAULT_CODEX_USER_AGENT_ARCH = "x64";
 const CODEX_VERSION_OVERRIDE_ENV = "CODEX_CLIENT_VERSION";
diff --git a/open-sse/config/codexModels.ts b/open-sse/config/codexModels.ts
index 05e3cb4d952d..a042c39d03e2 100644
--- a/open-sse/config/codexModels.ts
+++ b/open-sse/config/codexModels.ts
@@ -9,7 +9,12 @@ export const GPT_5_6_ULTRA_ALIAS_MODELS = new Set(["gpt-5.6-sol", "gpt-5.6-terra
 // STANDARD_EFFORT_SUFFIXES, so without this set neither would ever split off the
 // model id. `ultra` is an OmniRoute-side tier that goes out as wire effort `max`
 // while keeping parallel tool calls for sub-agent delegation.
-export const GPT_6_ALIAS_MODELS = new Set(["gpt-6-astra", "gpt-6-sol", "gpt-6-luna"]);
+export const GPT_6_ALIAS_MODELS = new Set([
+  "gpt-6.1-sol",
+  "gpt-6-astra",
+  "gpt-6-sol",
+  "gpt-6-luna",
+]);
 
 export function splitCodexReasoningSuffix(model: unknown): {
   baseModel: string;
@@ -26,7 +31,7 @@ export function splitCodexReasoningSuffix(model: unknown): {
     }
   }
 
-  const gpt6AliasMatch = /^(gpt-6-(?:astra|sol|luna))-(max|ultra)$/.exec(modelId);
+  const gpt6AliasMatch = /^(gpt-6-(?:astra|sol|luna)|gpt-6\.1-sol)-(max|ultra)$/.exec(modelId);
   if (gpt6AliasMatch) {
     const [, baseModel, alias] = gpt6AliasMatch;
     if (GPT_6_ALIAS_MODELS.has(baseModel) && !(baseModel === "gpt-6-luna" && alias === "ultra")) {
diff --git a/open-sse/config/providers/registry/codex/index.ts b/open-sse/config/providers/registry/codex/index.ts
index d992be928485..537cf5b2e617 100644
--- a/open-sse/config/providers/registry/codex/index.ts
+++ b/open-sse/config/providers/registry/codex/index.ts
@@ -24,6 +24,14 @@ export const codexProvider: RegistryEntry = {
     tokenUrl: "https://auth.openai.com/oauth/token",
   },
   models: [
+    // Codex OAuth uses the 872K window; the public API has a separate 1.05M limit.
+    { id: "gpt-6.1-sol", name: "GPT 6.1 Sol", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-low", name: "GPT 6.1 Sol (low)", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-medium", name: "GPT 6.1 Sol (medium)", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-high", name: "GPT 6.1 Sol (high)", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-xhigh", name: "GPT 6.1 Sol (xhigh)", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-max", name: "GPT 6.1 Sol (max)", ...GPT_5_6_CODEX_CAPABILITIES },
+    { id: "gpt-6.1-sol-ultra", name: "GPT 6.1 Sol (ultra)", ...GPT_5_6_CODEX_CAPABILITIES },
     { id: "gpt-6-sol", name: "GPT 6 sol", ...GPT_5_6_CODEX_CAPABILITIES },
     { id: "gpt-6-sol-low", name: "GPT 6 sol-low", ...GPT_5_6_CODEX_CAPABILITIES },
     { id: "gpt-6-sol-medium", name: "GPT 6 sol-medium", ...GPT_5_6_CODEX_CAPABILITIES },
diff --git a/open-sse/config/providers/registry/openai/index.ts b/open-sse/config/providers/registry/openai/index.ts
index d354735bf0f1..700c518cdbb5 100644
--- a/open-sse/config/providers/registry/openai/index.ts
+++ b/open-sse/config/providers/registry/openai/index.ts
@@ -11,6 +11,14 @@ export const openaiProvider: RegistryEntry = {
   authHeader: "bearer",
   defaultContextLength: 128000,
   models: [
+    // Sol tool calling requires Responses (OpenAI's GPT-6.1 Sol model reference).
+    {
+      id: "gpt-6.1-sol",
+      name: "GPT-6.1 Sol",
+      ...GPT_5_6_API_CAPABILITIES,
+      targetFormat: "openai-responses",
+      unsupportedParams: ["temperature", "top_p", "top_logprobs", "logprobs"],
+    },
     { id: "gpt-6-sol", name: "GPT 6 sol", ...GPT_5_6_API_CAPABILITIES },
     { id: "gpt-6-luna", name: "GPT 6 luna", ...GPT_5_6_API_CAPABILITIES },
     { id: "gpt-5.6", name: "GPT-5.6", ...GPT_5_6_API_CAPABILITIES },
diff --git a/open-sse/executors/codex.ts b/open-sse/executors/codex.ts
index 5cc95bac9d59..84d46c96857f 100644
--- a/open-sse/executors/codex.ts
+++ b/open-sse/executors/codex.ts
@@ -332,6 +332,7 @@ function normalizeServiceTierValue(value: unknown): string | undefined {
  * Update this table when Codex releases new models with different caps.
  */
 const MAX_EFFORT_BY_MODEL: Record<string, EffortLevel> = {
+  "gpt-6.1-sol": "ultra",
   "gpt-6-astra": "ultra",
   "gpt-6-sol": "ultra",
   "gpt-6-luna": "max",
@@ -1331,7 +1332,7 @@ export class CodexExecutor extends BaseExecutor {
     const explicitReasoning = normalizeEffortValue(reasoningRecord?.effort);
     const requestReasoningEffort = normalizeEffortValue(body.reasoning_effort);
     const fallbackReasoningEffort = allowConnectionReasoningDefaults
-      ? requestDefaults.reasoningEffort || "medium"
+      ? requestDefaults.reasoningEffort || (cleanModel === "gpt-6.1-sol" ? "low" : "medium")
       : undefined;
     // Issue #2331: model suffix aliases (for example gpt-5.5-xhigh) represent an
     // explicit model selection, so they must override client-injected defaults such
diff --git a/open-sse/services/model.ts b/open-sse/services/model.ts
index ac4acdc2162c..f5b4eb367af2 100644
--- a/open-sse/services/model.ts
+++ b/open-sse/services/model.ts
@@ -139,6 +139,13 @@ const CODEX_PREFERRED_UNPREFIXED_MODELS = new Set([
 // `gpt-5.5 → gpt-5.5-medium` entry is removed to preserve #2877's bare-id contract.
 const CODEX_PREFERRED_UNPREFIXED_MODEL_ALIASES = new Map<string, string>([]);
 export const CODEX_NATIVE_UNPREFIXED_MODELS = new Set([
+  "gpt-6.1-sol",
+  "gpt-6.1-sol-low",
+  "gpt-6.1-sol-medium",
+  "gpt-6.1-sol-high",
+  "gpt-6.1-sol-xhigh",
+  "gpt-6.1-sol-max",
+  "gpt-6.1-sol-ultra",
   "codex-auto-review",
   "gpt-6-sol",
   "gpt-6-sol-low",
diff --git a/open-sse/translator/request/openai-responses/helpers.ts b/open-sse/translator/request/openai-responses/helpers.ts
index 3d4aad6bbfd4..49dceb33cc20 100644
--- a/open-sse/translator/request/openai-responses/helpers.ts
+++ b/open-sse/translator/request/openai-responses/helpers.ts
@@ -53,7 +53,7 @@ export function normalizeResponsesReasoningEffort(value: unknown, model?: unknow
   const effort = toString(value).toLowerCase();
   const codexModel =
     typeof model === "string" &&
-    /^(?:(?:codex|cx)\/)?gpt-6-(?:astra|sol|luna)(?:-(?:low|medium|high|xhigh|max|ultra))?$/.test(
+    /^(?:(?:codex|cx)\/)?(?:gpt-6-(?:astra|sol|luna)|gpt-6\.1-sol)(?:-(?:low|medium|high|xhigh|max|ultra))?$/.test(
       model
     );
   return effort === "max" && !codexModel ? "xhigh" : effort;
diff --git a/src/lib/providers/codexFastTier.ts b/src/lib/providers/codexFastTier.ts
index 1ff6154a6d2b..76f43d9d701c 100644
--- a/src/lib/providers/codexFastTier.ts
+++ b/src/lib/providers/codexFastTier.ts
@@ -14,6 +14,7 @@ export type CodexFastTierValue = CodexServiceTier;
 export type CodexGlobalServiceMode = "none" | CodexServiceTier;
 
 export const CODEX_FAST_TIER_DEFAULT_SUPPORTED_MODELS: readonly string[] = [
+  "gpt-6.1-sol",
   "gpt-6-astra",
   "gpt-6-sol",
   "gpt-6-luna",
diff --git a/src/lib/usage/costCalculator.ts b/src/lib/usage/costCalculator.ts
index bedb8528f9c5..600df63ec067 100644
--- a/src/lib/usage/costCalculator.ts
+++ b/src/lib/usage/costCalculator.ts
@@ -101,6 +101,8 @@ export function getCodexFastCostMultiplier(
 
   const modelKey = stripCodexEffortSuffix(normalizeModelName(String(model || "")).toLowerCase());
   const compactModelKey = modelKey.replace(/-/g, "");
+  // Purchased credits use 2x; included subscription allowance uses 2.5x.
+  if (compactModelKey === "gpt6.1sol") return 2;
   // Codex Astra Fast is 2.5x Standard (https://developers.openai.com/codex/pricing).
   if (
     /^gpt-6-(?:astra|sol|luna)$/.test(modelKey) ||
@@ -168,7 +170,15 @@ export function computeCostFromPricing(
   cost += outputTokens * (outputPrice / 1_000_000);
 
   const reasoningTokens = tokens.reasoning ?? tokens.reasoning_tokens ?? 0;
-  if (reasoningTokens > 0) cost += reasoningTokens * (reasoningPrice / 1_000_000);
+  if (reasoningTokens > 0) {
+    const model = stripCodexEffortSuffix(normalizeModelName(options.model || ""));
+    const solOutputIncludesReasoning =
+      model === "gpt-6.1-sol" && ["openai", "codex", "cx"].includes(options.provider || "");
+    const reasoningRate = solOutputIncludesReasoning
+      ? Math.max(0, reasoningPrice - outputPrice)
+      : reasoningPrice;
+    cost += reasoningTokens * (reasoningRate / 1_000_000);
+  }
 
   if (cacheCreationTokens > 0) cost += cacheCreationTokens * (cacheCreationPrice / 1_000_000);
 
diff --git a/src/lib/vscode/reasoningMetadata.ts b/src/lib/vscode/reasoningMetadata.ts
index 528d1093c180..52808d00658e 100644
--- a/src/lib/vscode/reasoningMetadata.ts
+++ b/src/lib/vscode/reasoningMetadata.ts
@@ -21,7 +21,7 @@ const STANDARD_EFFORT_SUFFIX_PATTERN = /-(xhigh|high|medium|low|none)$/i;
 // effort suffixes. Without a match here the base id never splits off, and VS Code
 // discovery expands the alias again into invalid ids like `gpt-6-astra-max-high`.
 const EXTENDED_EFFORT_SUFFIX_PATTERN =
-  /^(.*(?:gpt-5\.6-(?:sol|terra|luna)|gpt-6-(?:astra|sol|luna)))-(max|ultra)$/i;
+  /^(.*(?:gpt-5\.6-(?:sol|terra|luna)|gpt-6-(?:astra|sol|luna)|gpt-6\.1-sol))-(max|ultra)$/i;
 const DEFAULT_REASONING_EFFORT = "none";
 const KNOWN_REASONING_EFFORTS = new Set(["none", "low", "medium", "high", "xhigh", "max", "ultra"]);
 
@@ -182,7 +182,14 @@ export function getReasoningVariantBaseModelId(modelId: string) {
 }
 
 export function getDefaultReasoningEffort(model: VscodeCatalogModel, supportedValues?: string[]) {
-  return inferSelectedReasoningEffort(model, supportedValues) || DEFAULT_REASONING_EFFORT;
+  const selected = inferSelectedReasoningEffort(model, supportedValues);
+  if (selected) return selected;
+  const parsed = parseModel(getCatalogModelName(model));
+  const provider = parsed.provider || model.owned_by;
+  if ((provider === "codex" || provider === "cx") && parsed.model === "gpt-6.1-sol") {
+    return "low";
+  }
+  return DEFAULT_REASONING_EFFORT;
 }
 
 export function buildReasoningConfigSchema(
diff --git a/src/shared/constants/clientIdentityProfiles.ts b/src/shared/constants/clientIdentityProfiles.ts
index f5438fb5f627..5cf299867b48 100644
--- a/src/shared/constants/clientIdentityProfiles.ts
+++ b/src/shared/constants/clientIdentityProfiles.ts
@@ -39,7 +39,7 @@ const CODEX_CLI_PROFILE: ClientIdentityProfile = Object.freeze({
   id: "codex-cli",
   label: "Codex CLI",
   headers: Object.freeze({
-    "User-Agent": "codex_cli_rs/0.156.1",
+    "User-Agent": "codex_cli_rs/0.159.2",
     originator: "codex_cli_rs",
   }),
 });
diff --git a/src/shared/constants/modelSpecs.ts b/src/shared/constants/modelSpecs.ts
index b5f785557c65..afa1b8e1f21f 100644
--- a/src/shared/constants/modelSpecs.ts
+++ b/src/shared/constants/modelSpecs.ts
@@ -92,6 +92,7 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
   },
 
   // Public model limits; the Codex registry supplies its smaller OAuth window.
+  "gpt-6.1-sol": { ...GPT_5_6_MODEL_SPEC, aliases: ["openai/gpt-6.1-sol"] },
   "gpt-6-sol": { ...GPT_5_6_MODEL_SPEC, aliases: ["openai/gpt-6-sol"] },
   "gpt-6-luna": { ...GPT_5_6_MODEL_SPEC, aliases: ["openai/gpt-6-luna"] },
   "gpt-6-astra": {
diff --git a/src/shared/constants/pricing/frontier-labs.ts b/src/shared/constants/pricing/frontier-labs.ts
index 55f673502ba4..802b08dd278e 100644
--- a/src/shared/constants/pricing/frontier-labs.ts
+++ b/src/shared/constants/pricing/frontier-labs.ts
@@ -20,6 +20,8 @@ import {
 
 export const DEFAULT_PRICING_FRONTIER = {
   openai: {
+    // Standard short-context USD/MTok; API cache writes have a separate rate.
+    "gpt-6.1-sol": { input: 2, output: 10, cached: 0.1, reasoning: 10, cache_creation: 2.5 },
     "gpt-5.6": GPT_5_6_SOL_PRICING,
     "gpt-5.6-sol": GPT_5_6_SOL_PRICING,
     "gpt-5.6-terra": GPT_5_6_TERRA_PRICING,
diff --git a/src/shared/constants/pricing/oauth-subscriptions.ts b/src/shared/constants/pricing/oauth-subscriptions.ts
index 3fae46211cbd..cf26c59caa7d 100644
--- a/src/shared/constants/pricing/oauth-subscriptions.ts
+++ b/src/shared/constants/pricing/oauth-subscriptions.ts
@@ -13,6 +13,10 @@ import {
   GPT_5_6_TERRA_PRICING,
 } from "./shared-tiers";
 
+// Codex: 50 / 2.5 / 250 credits per MTok at 25 credits/USD; no cache-write charge.
+// https://learn.chatgpt.com/docs/pricing
+const GPT_6_1_SOL_CODEX_PRICING = { input: 2, output: 10, cached: 0.1, reasoning: 10 };
+
 export const DEFAULT_PRICING_OAUTH = {
   cc: {
     "claude-fable-5": {
@@ -80,6 +84,14 @@ export const DEFAULT_PRICING_OAUTH = {
     },
   },
   cx: {
+    "gpt-6.1-sol": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-low": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-medium": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-high": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-xhigh": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-max": GPT_6_1_SOL_CODEX_PRICING,
+    "gpt-6.1-sol-ultra": GPT_6_1_SOL_CODEX_PRICING,
+
     "codex-auto-review": GPT_5_5_PRICING,
     // Codex uses credits per 1M tokens. OmniRoute stores the dollar-equivalent
     // values below at the documented conversion of 25 credits per USD.
diff --git a/src/shared/reasoning/effortStandardization.ts b/src/shared/reasoning/effortStandardization.ts
index 611433b8ff49..232790ab25b5 100644
--- a/src/shared/reasoning/effortStandardization.ts
+++ b/src/shared/reasoning/effortStandardization.ts
@@ -34,6 +34,10 @@ export function extendCodexGpt56EffortValues(
     return values;
   }
 
+  if (/^gpt-6\.1-sol(?:-(?:low|medium|high|xhigh|max|ultra))?$/.test(normalizedModel)) {
+    return ["low", "medium", "high", "xhigh", "max", "ultra"];
+  }
+
   const match = normalizedModel.match(
     /^gpt-5\.6-(sol|terra|luna)(?:-(?:none|low|medium|high|xhigh|max|ultra))?$/
   );
diff --git a/src/shared/validation/schemas/provider.ts b/src/shared/validation/schemas/provider.ts
index 72f3af64fe04..a51eb4939937 100644
--- a/src/shared/validation/schemas/provider.ts
+++ b/src/shared/validation/schemas/provider.ts
@@ -188,6 +188,7 @@ export const providerModelMutationSchema = z.object({
     .array(
       z.enum([
         "chat",
+        "responses",
         "embeddings",
         "rerank",
         "images",
diff --git a/tests/snapshots/provider/translate-path.json b/tests/snapshots/provider/translate-path.json
index f4204bd5ed8b..7f5429ba7aca 100644
--- a/tests/snapshots/provider/translate-path.json
+++ b/tests/snapshots/provider/translate-path.json
@@ -966,16 +966,16 @@
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.156.1 (<OS>; <ARCH>)",
-        "Version": "0.156.1",
+        "User-Agent": "codex-cli/0.159.2 (<OS>; <ARCH>)",
+        "Version": "0.159.2",
         "X-Codex-Beta-Features": "responses_websockets"
       },
       "nonStream": {
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.156.1 (<OS>; <ARCH>)",
-        "Version": "0.156.1",
+        "User-Agent": "codex-cli/0.159.2 (<OS>; <ARCH>)",
+        "Version": "0.159.2",
         "X-Codex-Beta-Features": "responses_websockets"
       },
       "oauth": {
@@ -983,8 +983,8 @@
         "Authorization": "Bearer <TOK>",
         "Content-Type": "application/json",
         "Openai-Beta": "responses=experimental",
-        "User-Agent": "codex-cli/0.156.1 (<OS>; <ARCH>)",
-        "Version": "0.156.1",
+        "User-Agent": "codex-cli/0.159.2 (<OS>; <ARCH>)",
+        "Version": "0.159.2",
         "X-Codex-Beta-Features": "responses_websockets"
       }
     },
diff --git a/tests/unit/claude-codex-identity-version-sync.test.ts b/tests/unit/claude-codex-identity-version-sync.test.ts
index 18a7c28d1cad..bc822a58e91c 100644
--- a/tests/unit/claude-codex-identity-version-sync.test.ts
+++ b/tests/unit/claude-codex-identity-version-sync.test.ts
@@ -42,10 +42,10 @@ test("Claude CLI is pinned to the captured 2.1.207 release", () => {
   assert.equal(id.CLAUDE_CODE_VERSION, "2.1.207");
 });
 
-test("Codex client is pinned to the captured 0.156.1 release", () => {
-  assert.equal(codexCfg.getCodexClientVersion(), "0.156.1");
-  assert.equal(codexCfg.getCodexUserAgent(), "codex-cli/0.156.1 (Windows 10.0.26200; x64)");
-  assert.equal(codexCfg.getCodexDefaultHeaders().Version, "0.156.1");
+test("Codex client is pinned to the captured 0.159.2 release", () => {
+  assert.equal(codexCfg.getCodexClientVersion(), "0.159.2");
+  assert.equal(codexCfg.getCodexUserAgent(), "codex-cli/0.159.2 (Windows 10.0.26200; x64)");
+  assert.equal(codexCfg.getCodexDefaultHeaders().Version, "0.159.2");
 });
 
 test("Codex CLI preset and optional Docker CLI stay aligned with the wire version", () => {
diff --git a/tests/unit/client-identity-profiles.test.ts b/tests/unit/client-identity-profiles.test.ts
index 3837961f951b..c6327ed6602c 100644
--- a/tests/unit/client-identity-profiles.test.ts
+++ b/tests/unit/client-identity-profiles.test.ts
@@ -43,7 +43,7 @@ test("getClientIdentityProfileHeaders: known CLI profiles expose their preset he
   assert.equal(claudeCli["X-App"], "cli");
 
   const codexCli = getClientIdentityProfileHeaders("codex-cli");
-  assert.equal(codexCli["User-Agent"], "codex_cli_rs/0.156.1");
+  assert.equal(codexCli["User-Agent"], "codex_cli_rs/0.159.2");
   assert.equal(codexCli.originator, "codex_cli_rs");
 
   const geminiCli = getClientIdentityProfileHeaders("gemini-cli");
@@ -80,7 +80,7 @@ test("a selected profile's headers land in providerSpecificData.customHeaders",
     customHeaders: { ...profileHeaders, "X-Operator-Set": "keep-me" },
   };
 
-  assert.equal(providerSpecificData.customHeaders["User-Agent"], "codex_cli_rs/0.156.1");
+  assert.equal(providerSpecificData.customHeaders["User-Agent"], "codex_cli_rs/0.159.2");
   assert.equal(providerSpecificData.customHeaders.originator, "codex_cli_rs");
   assert.equal(providerSpecificData.customHeaders["X-Operator-Set"], "keep-me");
 });
diff --git a/tests/unit/codex-fast-tier.test.ts b/tests/unit/codex-fast-tier.test.ts
index 82c2aada21eb..1f5d24d0bbdc 100644
--- a/tests/unit/codex-fast-tier.test.ts
+++ b/tests/unit/codex-fast-tier.test.ts
@@ -42,6 +42,7 @@ test("Codex global service mode distinguishes no setting from explicit tiers", (
       enabled: true,
       tier: "default",
       supportedModels: [
+        "gpt-6.1-sol",
         "gpt-6-astra",
         "gpt-6-sol",
         "gpt-6-luna",
diff --git a/tests/unit/codex-gpt6-astra.test.ts b/tests/unit/codex-gpt6-astra.test.ts
index 27e3cc936640..688620b6bdf2 100644
--- a/tests/unit/codex-gpt6-astra.test.ts
+++ b/tests/unit/codex-gpt6-astra.test.ts
@@ -138,8 +138,8 @@ test("VS Code discovery splits Astra's extended effort aliases off the base id",
 test("Codex identifies as a client version Astra accepts", () => {
   // Astra rejects older clients with HTTP 400 "requires a newer version of Codex"
   // (upstream issue #12761), so the advertised identity gates the whole model.
-  assert.equal(getCodexClientVersion(), "0.156.1");
-  assert.equal(getCodexDefaultHeaders().Version, "0.156.1");
+  assert.equal(getCodexClientVersion(), "0.159.2");
+  assert.equal(getCodexDefaultHeaders().Version, "0.159.2");
 });
 
 test("Codex Fast bills GPT-6 Astra at the 2.5x multiplier", () => {
diff --git a/tests/unit/codex-gpt61-sol.test.ts b/tests/unit/codex-gpt61-sol.test.ts
new file mode 100644
index 000000000000..dea8b3b3adc2
--- /dev/null
+++ b/tests/unit/codex-gpt61-sol.test.ts
@@ -0,0 +1,218 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import {
+  getModelsByProviderId,
+  getModelTargetFormat,
+} from "../../open-sse/config/providerModels.ts";
+import { CodexExecutor } from "../../open-sse/executors/codex.ts";
+import { DefaultExecutor } from "../../open-sse/executors/default.ts";
+import { getCodexUpstreamModel } from "../../open-sse/config/codexModels.ts";
+import { getModelInfoCore, parseModel } from "../../open-sse/services/model.ts";
+import { openaiToOpenAIResponsesRequest } from "../../open-sse/translator/request/openai-responses/toResponses.ts";
+import { getModelSpec } from "../../src/shared/constants/modelSpecs.ts";
+import { getPricingForModel } from "../../src/shared/constants/pricing.ts";
+import {
+  computeCostFromPricing,
+  getCodexFastCostMultiplier,
+} from "../../src/lib/usage/costCalculator.ts";
+import { resolveCodexGlobalFastServiceTier } from "../../src/lib/providers/codexFastTier.ts";
+import {
+  getDefaultReasoningEffort,
+  getReasoningEffortValues,
+  getReasoningVariantBaseModelId,
+} from "../../src/lib/vscode/reasoningMetadata.ts";
+import { providerModelMutationSchema } from "../../src/shared/validation/schemas/provider.ts";
+import { normalizeCodexModelsResponse } from "../../src/app/api/providers/[id]/models/discovery/codex.ts";
+
+const MODEL = "gpt-6.1-sol";
+const EFFORTS = ["low", "medium", "high", "xhigh", "max", "ultra"];
+const IDS = [MODEL, ...EFFORTS.map((effort) => `${MODEL}-${effort}`)];
+
+test.after(async () => {
+  const { resetDbInstance } = await import("../../src/lib/db/core.ts");
+  resetDbInstance();
+});
+
+type ResponsesBody = Record<string, unknown> & {
+  reasoning: { effort: string; summary?: string };
+  tools: { name: string }[];
+};
+
+function transform(model: string, body: Record<string, unknown> = {}, providerSpecificData = {}) {
+  return new CodexExecutor().transformRequest(model, { model, input: [], ...body }, true, {
+    requestEndpointPath: "/responses",
+    providerSpecificData,
+  }) as ResponsesBody;
+}
+
+test("Sol has provider-specific context limits and routes tool requests through Responses", async () => {
+  const catalog = getModelsByProviderId("codex");
+  assert.deepEqual(
+    catalog.filter((m) => m.id.startsWith(MODEL)).map((m) => m.id),
+    IDS
+  );
+  for (const id of IDS) {
+    const entry = catalog.find((m) => m.id === id);
+    assert.equal(entry?.contextLength, 872000);
+    assert.equal(entry?.maxOutputTokens, 128000);
+    assert.equal(entry?.toolCalling, true);
+    assert.equal(entry?.supportsVision, true);
+    assert.equal(getModelTargetFormat("cx", id), "openai-responses");
+    assert.equal((await getModelInfoCore(id, {})).provider, "codex");
+    assert.equal(getCodexUpstreamModel(id), MODEL, "account eligibility uses the wire model");
+  }
+  const api = getModelsByProviderId("openai").find((m) => m.id === MODEL);
+  assert.equal(api?.contextLength, 1050000);
+  assert.equal(api?.maxOutputTokens, 128000);
+  assert.ok(api?.unsupportedParams?.includes("temperature"));
+  assert.equal(getModelSpec(`openai/${MODEL}`)?.contextWindow, 1050000);
+  assert.equal(getModelTargetFormat("openai", MODEL), "openai-responses");
+  assert.equal(
+    new DefaultExecutor("openai").buildUrl(MODEL, true),
+    "https://api.openai.com/v1/responses"
+  );
+  assert.equal(parseModel(`openai/${MODEL}`).provider, "openai");
+  assert.equal((await getModelInfoCore(MODEL, { [MODEL]: `openai/${MODEL}` })).provider, "openai");
+});
+
+test("Sol aliases override injected effort and keep max on native and translated requests", () => {
+  for (const effort of EFFORTS) {
+    const result = transform(`${MODEL}-${effort}`, {
+      reasoning: { effort: "medium", summary: "detailed" },
+    });
+    assert.equal(result.model, MODEL);
+    assert.equal(result.reasoning.effort, effort === "ultra" ? "max" : effort);
+    assert.equal(result.reasoning.summary, "detailed");
+  }
+  assert.equal(transform(MODEL, { reasoning: { effort: "max" } }).reasoning.effort, "max");
+  const translated = openaiToOpenAIResponsesRequest(
+    MODEL,
+    {
+      model: MODEL,
+      messages: [{ role: "user", content: "test" }],
+      reasoning_effort: "max",
+      tools: [{ type: "function", function: { name: "lookup", parameters: { type: "object" } } }],
+    },
+    true,
+    {}
+  ) as ResponsesBody;
+  assert.equal(translated.reasoning.effort, "max");
+  assert.equal(translated.tools[0].name, "lookup");
+});
+
+test("Sol defaults to low while preserving explicit request and connection preferences", () => {
+  assert.equal(transform(MODEL).reasoning.effort, "low");
+  assert.equal(transform(MODEL, { reasoning_effort: "high" }).reasoning.effort, "high");
+  assert.equal(
+    transform(MODEL, {}, { requestDefaults: { reasoningEffort: "xhigh" } }).reasoning.effort,
+    "xhigh"
+  );
+  assert.equal(transform("gpt-6-sol").reasoning.effort, "medium");
+});
+
+test("Sol VS Code metadata exposes supported efforts without generating nested suffixes", () => {
+  const model = { id: `cx/${MODEL}`, owned_by: "codex", capabilities: { reasoning: true } };
+  assert.deepEqual(getReasoningEffortValues(model), EFFORTS);
+  assert.equal(getDefaultReasoningEffort(model), "low");
+  for (const effort of ["max", "ultra"]) {
+    assert.equal(getReasoningVariantBaseModelId(`cx/${MODEL}-${effort}`), `cx/${MODEL}`);
+    assert.equal(getDefaultReasoningEffort({ ...model, id: `cx/${MODEL}-${effort}` }), effort);
+  }
+});
+
+test("Sol prices cached input independently from GPT-6 Sol and makes Fast eligible", () => {
+  for (const id of IDS) {
+    const pricing = getPricingForModel("cx", id);
+    assert.equal(pricing?.input, 2);
+    assert.equal(pricing?.cached, 0.1);
+    assert.equal(pricing?.output, 10);
+    assert.equal(pricing?.cache_creation, undefined);
+    assert.equal(getCodexFastCostMultiplier("cx", id, "priority"), 2);
+    assert.equal(getCodexFastCostMultiplier("codex", id, "fast"), 2);
+    assert.equal(getCodexFastCostMultiplier("codex", id, "default"), 1);
+  }
+  assert.equal(getPricingForModel("openai", MODEL)?.cache_creation, 2.5);
+  assert.equal(getPricingForModel("cx", "gpt-6-sol")?.cached, 0.2);
+  assert.ok(
+    resolveCodexGlobalFastServiceTier({
+      codexServiceTier: { enabled: true },
+    }).supportedModels.includes(MODEL)
+  );
+});
+
+test("Sol cost counts cached input and reasoning-inclusive output once", () => {
+  const tokens = { input: 100000, cacheRead: 50000, output: 2000, reasoning: 1000 };
+  const pricing = getPricingForModel("cx", MODEL);
+  for (const provider of ["cx", "codex", "openai"]) {
+    const cost = computeCostFromPricing(pricing, tokens, { provider, model: MODEL });
+    assert.ok(Math.abs(cost - 0.125) < 1e-10, `${provider}: ${cost}`);
+  }
+  const fast = computeCostFromPricing(pricing, tokens, {
+    provider: "cx",
+    model: `${MODEL}-max`,
+    serviceTier: "priority",
+  });
+  assert.ok(Math.abs(fast - 0.25) < 1e-10);
+  // Other providers retain the fork's existing separate-reasoning accounting.
+  const existing = computeCostFromPricing(pricing, tokens, { provider: "custom", model: MODEL });
+  assert.ok(Math.abs(existing - 0.135) < 1e-10);
+});
+
+test("discovered Sol Responses endpoints pass import validation and unknown endpoints fail", () => {
+  const discovered = normalizeCodexModelsResponse({ models: [{ slug: MODEL }] })[0];
+  const parsed = providerModelMutationSchema.parse({
+    provider: "codex",
+    modelId: MODEL,
+    apiFormat: "responses",
+    supportedEndpoints: discovered.supportedEndpoints,
+  });
+  assert.deepEqual(parsed.supportedEndpoints, ["responses"]);
+  assert.equal(
+    providerModelMutationSchema.safeParse({
+      provider: "codex",
+      modelId: MODEL,
+      supportedEndpoints: ["arbitrary-endpoint"],
+    }).success,
+    false
+  );
+});
+
+test("Sol streams tool events and retains Ultra parallel calls with the updated client identity", async (t) => {
+  const executor = new CodexExecutor();
+  const captured: { headers: Headers; body: Record<string, unknown> }[] = [];
+  const sse = [
+    'event: response.created\ndata: {"type":"response.created","response":{"id":"resp_sol","object":"response","status":"in_progress"}}\n\n',
+    'event: response.output_item.added\ndata: {"type":"response.output_item.added","output_index":0,"item":{"id":"fc_sol","type":"function_call","call_id":"call_sol","name":"lookup","arguments":"{}"}}\n\n',
+    'event: response.completed\ndata: {"type":"response.completed","response":{"id":"resp_sol","status":"completed","output":[{"type":"function_call","call_id":"call_sol","name":"lookup","arguments":"{}"}]}}\n\n',
+  ].join("");
+  t.mock.method(globalThis, "fetch", async (_url: unknown, init: RequestInit) => {
+    captured.push({ headers: new Headers(init.headers), body: JSON.parse(String(init.body)) });
+    return new Response(sse, { headers: { "content-type": "text/event-stream" } });
+  });
+  for (const effort of ["ultra", "high"]) {
+    const model = `${MODEL}-${effort}`;
+    const result = await executor.execute({
+      model,
+      stream: true,
+      credentials: { accessToken: "test-token" },
+      clientHeaders: { "X-OpenAI-Internal-Codex-Responses-Lite": "true" },
+      body: {
+        _nativeCodexPassthrough: true,
+        model,
+        input: [{ role: "user", content: "test" }],
+        parallel_tool_calls: true,
+        tools: [{ type: "function", name: "lookup", parameters: { type: "object" } }],
+      },
+    });
+    assert.equal(result.response.status, 200);
+    const output = await result.response.text();
+    assert.match(output, /response.completed/);
+    assert.match(output, /call_sol/);
+    const sent = captured.at(-1)!;
+    assert.equal(sent.headers.get("version"), "0.159.2");
+    assert.match(sent.headers.get("user-agent") || "", /0\.159\.2/);
+    assert.equal(sent.body.model, MODEL);
+    assert.equal(sent.body.parallel_tool_calls, effort === "ultra");
+    assert.equal((sent.body.tools as { name: string }[])[0].name, "lookup");
+  }
+});
diff --git a/tests/unit/codex-sol-luna.test.ts b/tests/unit/codex-sol-luna.test.ts
index d43fa723b982..9ba8491c0ed0 100644
--- a/tests/unit/codex-sol-luna.test.ts
+++ b/tests/unit/codex-sol-luna.test.ts
@@ -116,5 +116,5 @@ test("caller version passes through with safe pinned fallback", () => {
     executor.buildHeaders({ accessToken: "opaque" }, true, { version: "0.157.0" }).Version,
     "0.157.0"
   );
-  assert.equal(executor.buildHeaders({ accessToken: "opaque" }, true).Version, "0.156.1");
+  assert.equal(executor.buildHeaders({ accessToken: "opaque" }, true).Version, "0.159.2");
 });
diff --git a/tests/unit/executor-codex.test.ts b/tests/unit/executor-codex.test.ts
index 8e993fcd24a7..24c9b649bb59 100644
--- a/tests/unit/executor-codex.test.ts
+++ b/tests/unit/executor-codex.test.ts
@@ -185,10 +185,10 @@ test("CodexExecutor.buildHeaders binds workspace ids and disables SSE accept for
   assert.equal(standardHeaders.Authorization, "Bearer codex-token");
   assert.equal(standardHeaders.Accept, "text/event-stream");
   assert.equal(standardHeaders["chatgpt-account-id"], "workspace-1");
-  assert.equal(standardHeaders.Version, "0.156.1");
+  assert.equal(standardHeaders.Version, "0.159.2");
   assert.equal(standardHeaders["Openai-Beta"], "responses=experimental");
   assert.equal(standardHeaders["X-Codex-Beta-Features"], "responses_websockets");
-  assert.equal(standardHeaders["User-Agent"], "codex-cli/0.156.1 (Windows 10.0.26200; x64)");
+  assert.equal(standardHeaders["User-Agent"], "codex-cli/0.159.2 (Windows 10.0.26200; x64)");
   assert.equal(compactHeaders.Accept, "application/json");
 });
 
@@ -302,7 +302,7 @@ test("CodexExecutor.buildHeaders honors safe env overrides for Version and User-
     },
     () => {
       const headers = executor.buildHeaders({ accessToken: "codex-token" }, true);
-      assert.equal(headers.Version, "0.156.1");
+      assert.equal(headers.Version, "0.159.2");
       assert.equal(headers["User-Agent"], "custom-codex/9.9.9");
     }
   );
@@ -1065,8 +1065,8 @@ test("CodexExecutor.execute captures the exact websocket request body before sen
   assert.equal(sentBody.model, "gpt-5.5");
   assert.equal(websocketHeaders?.["OpenAI-Beta"], "responses_websockets=2026-02-06");
   assert.equal(websocketHeaders?.Origin, "https://chatgpt.com");
-  assert.equal(websocketHeaders?.Version, "0.156.1");
-  assert.equal(websocketHeaders?.["User-Agent"], "codex-cli/0.156.1 (Windows 10.0.26200; x64)");
+  assert.equal(websocketHeaders?.Version, "0.159.2");
+  assert.equal(websocketHeaders?.["User-Agent"], "codex-cli/0.159.2 (Windows 10.0.26200; x64)");
 });
 
 test("CodexExecutor.execute adds CLI-like session identity headers without changing response flow", async () => {
diff --git a/tests/unit/openai-gpt56-catalog.test.ts b/tests/unit/openai-gpt56-catalog.test.ts
index f1eb8cd57137..9560f6ce94ea 100644
--- a/tests/unit/openai-gpt56-catalog.test.ts
+++ b/tests/unit/openai-gpt56-catalog.test.ts
@@ -9,7 +9,7 @@ const EXPECTED_MODELS = ["gpt-5.6", "gpt-5.6-sol", "gpt-5.6-terra", "gpt-5.6-lun
 
 test("OpenAI API catalog exposes the public GPT-5.6 family and keeps GPT-5.4", () => {
   const models = getModelsByProviderId("openai");
-  const expectedLeadingModels = ["gpt-6-sol", "gpt-6-luna", ...EXPECTED_MODELS];
+  const expectedLeadingModels = ["gpt-6.1-sol", "gpt-6-sol", "gpt-6-luna", ...EXPECTED_MODELS];
 
   assert.deepEqual(
     models.slice(0, expectedLeadingModels.length).map((model) => model.id),
diff --git a/tests/unit/provider-models-route-codex.test.ts b/tests/unit/provider-models-route-codex.test.ts
index 16a5ee077e4e..b36348541f8a 100644
--- a/tests/unit/provider-models-route-codex.test.ts
+++ b/tests/unit/provider-models-route-codex.test.ts
@@ -159,11 +159,11 @@ test("provider models route merges live Codex models with the local catalog then
   assert.equal(body.discoveredCandidateCount, undefined);
   assert.deepEqual(seenRequests, [
     {
-      url: "https://chatgpt.com/backend-api/codex/models?client_version=0.156.1",
+      url: "https://chatgpt.com/backend-api/codex/models?client_version=0.159.2",
       authorization: "Bearer codex-access-token",
       workspaceId: "account-123",
       originator: "codex_cli_rs",
-      userAgent: "codex-cli/0.156.1 (Windows 10.0.26200; x64)",
+      userAgent: "codex-cli/0.159.2 (Windows 10.0.26200; x64)",
     },
     {
       url: "https://raw.githubusercontent.com/openai/codex/refs/heads/main/codex-rs/models-manager/models.json",