diff --git a/src/wokwi_client/client.py b/src/wokwi_client/client.py
index 5d459eb..6f4ad4d 100644
--- a/src/wokwi_client/client.py
+++ b/src/wokwi_client/client.py
@@ -20,6 +20,7 @@
     upload,
     upload_file,
     upload_idf_firmware,
+    upload_text,
 )
 from .framebuffer import (
     read_framebuffer_png_bytes,
@@ -90,6 +91,19 @@ async def upload(self, name: str, content: bytes) -> None:
         """
         await upload(self._transport, name, content)
 
+    async def upload_text(self, name: str, content: str) -> None:
+        """
+        Upload a text file to the simulator from a string.
+
+        Use this method for text-based files such as JSON chip definitions
+        (``*.chip.json``). For binary files, use :meth:`upload`.
+
+        Args:
+            name: The name to use for the uploaded file.
+            content: The file content as a string.
+        """
+        await upload_text(self._transport, name, content)
+
     async def upload_file(self, filename: str, local_path: Optional[Path] = None) -> str:
         """
         Upload a local file to the simulator.
diff --git a/src/wokwi_client/client_sync.pyi b/src/wokwi_client/client_sync.pyi
index a76f8a6..ca95594 100644
--- a/src/wokwi_client/client_sync.pyi
+++ b/src/wokwi_client/client_sync.pyi
@@ -38,6 +38,7 @@ class WokwiClientSync:
 
     # Methods mirrored from WokwiClient (sync variants)
     def upload(self, name: str, content: bytes) -> None: ...
+    def upload_text(self, name: str, content: str) -> None: ...
     def upload_file(self, filename: str, local_path: Path | None = None) -> str: ...
     def upload_idf_firmware(self, flasher_args_path: str | Path) -> IdfFirmwareUploadResult: ...
     def download(self, name: str) -> bytes: ...
diff --git a/src/wokwi_client/file_ops.py b/src/wokwi_client/file_ops.py
index 021b3c1..c45cf37 100644
--- a/src/wokwi_client/file_ops.py
+++ b/src/wokwi_client/file_ops.py
@@ -8,10 +8,12 @@
 
 from wokwi_client.idf import resolveIdfFirmware
 
-from .models import UploadParams
+from .models import TextUploadParams, UploadParams
 from .protocol_types import ResponseMessage
 from .transport import Transport
 
+_TEXT_EXTENSIONS = {".json", ".toml", ".txt", ".yaml", ".yml"}
+
 
 class FlashSection:
     """A flash section with its offset and remote file name."""
@@ -33,8 +35,15 @@ async def upload_file(
     transport: Transport, filename: str, local_path: Optional[Path] = None
 ) -> str:
     firmware_path = local_path or filename
-    content = Path(firmware_path).read_bytes()
-    await upload(transport, filename, content)
+    file_path = Path(firmware_path)
+    # Use the remote filename's extension to determine the upload format,
+    # since the server's interpretation is based on the destination name.
+    if Path(filename).suffix in _TEXT_EXTENSIONS:
+        text_content = file_path.read_text(encoding="utf-8")
+        await upload_text(transport, filename, text_content)
+    else:
+        content = file_path.read_bytes()
+        await upload(transport, filename, content)
     return filename
 
 
@@ -55,5 +64,10 @@ async def upload(transport: Transport, name: str, content: bytes) -> ResponseMes
     return await transport.request("file:upload", params.model_dump())
 
 
+async def upload_text(transport: Transport, name: str, content: str) -> ResponseMessage:
+    params = TextUploadParams(name=name, text=content)
+    return await transport.request("file:upload", params.model_dump())
+
+
 async def download(transport: Transport, name: str) -> ResponseMessage:
     return await transport.request("file:download", {"name": name})
diff --git a/src/wokwi_client/models.py b/src/wokwi_client/models.py
index e085a31..502bc0d 100644
--- a/src/wokwi_client/models.py
+++ b/src/wokwi_client/models.py
@@ -10,6 +10,11 @@ class UploadParams(BaseModel):
     binary: str  # base64
 
 
+class TextUploadParams(BaseModel):
+    name: str
+    text: str
+
+
 class SimulationParams(BaseModel):
     firmware: str
     elf: str