diff --git a/bun.lock b/bun.lock
index d55db4568d34..3c003226f87b 100644
--- a/bun.lock
+++ b/bun.lock
@@ -572,6 +572,7 @@
         "ignore": "7.0.5",
         "immer": "11.1.4",
         "jsonc-parser": "3.3.1",
+        "jsonrepair": "3.14.0",
         "mime-types": "3.0.2",
         "minimatch": "10.0.3",
         "npm-package-arg": "13.0.2",
@@ -3974,6 +3975,8 @@
 
     "jsonparse": ["jsonparse@1.3.1", "", {}, "sha512-POQXvpdL69+CluYsillJ7SUhKvytYjW9vG/GKpnf+xP8UWgYEM/RaMzHHofbALDiKbbP1W8UEYmgGl39WkPZsg=="],
 
+    "jsonrepair": ["jsonrepair@3.14.0", "", { "bin": { "jsonrepair": "bin/cli.js" } }, "sha512-tWPGKMZf/8UPim+fcW2EfcQ/d/7aKUrP6IECz9G3Tu6Q5dX0orSleqJ9z6sSw7qrQkjF8/Edo4DvsWBZ8H+HNg=="],
+
     "jsonwebtoken": ["jsonwebtoken@9.0.3", "", { "dependencies": { "jws": "^4.0.1", "lodash.includes": "^4.3.0", "lodash.isboolean": "^3.0.3", "lodash.isinteger": "^4.0.4", "lodash.isnumber": "^3.0.3", "lodash.isplainobject": "^4.0.6", "lodash.isstring": "^4.0.1", "lodash.once": "^4.0.0", "ms": "^2.1.1", "semver": "^7.5.4" } }, "sha512-MT/xP0CrubFRNLNKvxJ2BYfy53Zkm++5bX9dtuPbqAeQpTVe0MQTFhao8+Cp//EmJp244xt6Drw/GVEGCUj40g=="],
 
     "just-diff": ["just-diff@6.0.2", "", {}, "sha512-S59eriX5u3/QhMNq3v/gm8Kd0w8OS6Tz2FS1NG4blv+z0MuQcBRJyFWjdovM0Rad4/P4aUPFtnkNjMjyMlMSYA=="],
diff --git a/packages/opencode/package.json b/packages/opencode/package.json
index b775b1280d42..36a801c60b44 100644
--- a/packages/opencode/package.json
+++ b/packages/opencode/package.json
@@ -125,6 +125,7 @@
     "ignore": "7.0.5",
     "immer": "11.1.4",
     "jsonc-parser": "3.3.1",
+    "jsonrepair": "3.14.0",
     "mime-types": "3.0.2",
     "minimatch": "10.0.3",
     "npm-package-arg": "13.0.2",
diff --git a/packages/opencode/src/session/llm.ts b/packages/opencode/src/session/llm.ts
index adacfc431549..b20822365341 100644
--- a/packages/opencode/src/session/llm.ts
+++ b/packages/opencode/src/session/llm.ts
@@ -26,6 +26,7 @@ import { EffectBridge } from "@/effect/bridge"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 import * as Option from "effect/Option"
 import * as OtelTracer from "@effect/opentelemetry/Tracer"
+import { jsonrepair } from "jsonrepair"
 import { LLMAISDK } from "./llm/ai-sdk"
 import { LLMNativeRuntime } from "./llm/native-runtime"
 import { LLMRequestPrep } from "./llm/request"
@@ -301,6 +302,22 @@ const live: Layer.Layer<
                 toolName: lower,
               }
             }
+
+            const toolInput = failed.toolCall.input
+            if (typeof toolInput === "string" && toolInput.trim().startsWith("{")) {
+              try {
+                const repaired = jsonrepair(toolInput)
+                if (repaired !== toolInput) {
+                  return {
+                    ...failed.toolCall,
+                    input: repaired,
+                  }
+                }
+              } catch {
+                // jsonrepair failed, fall through to invalid tool handler
+              }
+            }
+
             return {
               ...failed.toolCall,
               input: JSON.stringify({