gRPC for Python

1.78.0 verified Tue May 12 auth: no python install: verified quickstart: stale

gRPC is a high-performance, open-source RPC framework that uses HTTP/2 for transport. The 'grpcio' package provides the core gRPC functionality for Python, enabling developers to build efficient and scalable services. The current version is 1.78.0, with regular updates to enhance performance and address issues.

pip install grpcio

Common errors

error ModuleNotFoundError: No module named 'grpc' ↓

cause This error occurs when the `grpcio` package (or its associated tools like `grpcio-tools`) is not installed or not accessible in the Python environment where the code is being run.

fix

Install the necessary gRPC packages using pip: pip install grpcio grpcio-tools

error Connection refused ↓

cause This typically indicates that the gRPC client cannot establish a TCP connection to the gRPC server. Common reasons include the server not running, an incorrect server address/port, firewall issues, or network connectivity problems. The client might also report `grpc._channel._InactiveRpcError: <_InactiveRpcError of RPC that terminated with: status = StatusCode.UNAVAILABLE` in this scenario.

fix

Verify that the gRPC server is running and listening on the expected address and port. Check firewall rules (e.g., ufw, iptables) to ensure the port is open. Ensure the client is connecting to the correct IP address and port, possibly binding the server to 0.0.0.0 or [::] instead of localhost for external access.

error AttributeError: module 'grpc' has no attribute 'aio' ↓

cause This error arises when trying to use the asynchronous gRPC API (`grpc.aio`) with an older version of `grpcio` that does not support it, or if there's an issue with the installation of the `grpcio` package's C extensions.

fix

Upgrade grpcio to a version that supports asyncio (e.g., grpcio>=1.32.0) by running pip install --upgrade grpcio grpcio-tools. If issues persist, try reinstalling with --no-cache-dir to ensure a fresh build.

error SSL: CERTIFICATE_VERIFY_FAILED ↓

cause This error occurs during a secure (TLS/SSL) gRPC connection when the client cannot verify the server's SSL certificate. This can be due to an invalid certificate, a self-signed certificate not trusted by the client, or an outdated `certifi` package.

fix

Ensure the server is presenting a valid, trusted SSL certificate. If using self-signed certificates for development, configure the client to trust them explicitly. Update certifi (if applicable) using pip install --upgrade certifi. For environments where proxy issues might interfere with certificate validation, setting grpc.enable_http_proxy=0 in channel options might help.

error error: Microsoft Visual C++ 14.0 or greater is required. ↓

cause Installing grpcio from source on Windows requires the Microsoft Visual C++ build tools to compile its C extensions.

fix

Install the 'Build Tools for Visual Studio' from Microsoft's website, ensuring the 'Desktop development with C++' workload is selected.

Warnings

breaking Python 2.7 support was removed on January 1, 2020. ↓

fix Upgrade to Python 3.9 or higher.

gotcha Generated Python code from .proto files may have absolute imports, causing import errors in certain project structures. ↓

fix Ensure .proto files are organized to match the desired Python package structure, or adjust import statements accordingly.

gotcha Installation issues may arise due to setuptools version conflicts. ↓

fix Downgrade setuptools to version 49.6.0 if installation fails.

gotcha Test execution timed out. ↓

fix Investigate test logs for hanging processes, deadlocks, or infinite loops that prevent tests from completing within the allotted time.

gotcha Test execution timed out. This could be due to long-running tests, resource constraints, or an infinite loop in the code. ↓

fix Review test duration, optimize test cases, check for infinite loops, and ensure sufficient resources are allocated for test execution.

Install

pip install grpcio-tools

Install compatibility verified last tested: 2026-05-12

python os / libc variant status wheel install import disk

3.10 alpine (musl) grpcio - - 0.14s 38.2M

3.10 alpine (musl) grpcio-tools - - 0.13s 49.8M

3.10 slim (glibc) grpcio - - 0.10s 36M

3.10 slim (glibc) grpcio-tools - - 0.09s 45M

3.11 alpine (musl) grpcio - - 0.24s 40.3M

3.11 alpine (musl) grpcio-tools - - 0.23s 52.3M

3.11 slim (glibc) grpcio - - 0.18s 38M

3.11 slim (glibc) grpcio-tools - - 0.20s 48M

3.12 alpine (musl) grpcio - - 0.46s 32.1M

3.12 alpine (musl) grpcio-tools - - 0.46s 53.0M

3.12 slim (glibc) grpcio - - 0.41s 30M

3.12 slim (glibc) grpcio-tools - - 0.43s 49M

3.13 alpine (musl) grpcio - - 0.47s 31.7M

3.13 alpine (musl) grpcio-tools - - 0.49s 52.7M

3.13 slim (glibc) grpcio - - 0.40s 29M

3.13 slim (glibc) grpcio-tools - - 0.41s 48M

3.9 alpine (musl) grpcio - - 0.17s 37.7M

3.9 alpine (musl) grpcio-tools - - 0.13s 49.3M

3.9 slim (glibc) grpcio - - 0.12s 35M

3.9 slim (glibc) grpcio-tools - - 0.13s 45M

Imports

grpc
```
import grpc
```
Core gRPC module for Python
grpc_tools
```
import grpc_tools
```
Module for gRPC tools, including the protocol buffer compiler

Quickstart stale last tested: 2026-04-23

Basic setup for a gRPC server in Python

import grpc
from concurrent import futures

# Define the server
server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))

# Add your service implementations here

# Start the server
server.add_insecure_port('[::]:50051')
server.start()
server.wait_for_termination()