ADIOS2 : The Adaptable Input Output System version 2

June 2, 2026 · View on GitHub

ADIOS2 : The Adaptable Input Output System version 2

ADIOS2 is an adaptable, scalable, and unified framework for scientific data I/O. It transports self-describing variables and attributes across files, networks, and memory using a single API, and is used in production on the world's largest supercomputers.

Features

Unified I/O API: same interface for files, wide-area networks, and in-memory staging; switch transport without changing application code
BP format: self-describing binary-packed format (.bp) with rapid metadata extraction and built-in compression support
MPI-native: scales from laptop to petabyte workloads on the largest HPC systems; serial use also supported
Streaming and step-based: asynchronous, grouped variable transport with an explicit steps abstraction for in-situ and in-transit workflows
Multiple language bindings: C++17, Python, C99, Fortran 90, and Matlab
Compression operators: ZFP, SZ, MGARD, Blosc2, PNG, and others
Encryption operators: symmetric (AES-256-GCM) and asymmetric encryption available for data at rest
In-situ/in-transit engines: SST and DataMan engines for code coupling over RDMA, MPI, and TCP without touching files
DAOS engine: writes and reads datasets through the DAOS data plane (native object API) directly, with no dfuse or POSIX interception required
Plugin support: extend ADIOS2 with custom engines and operators via shared-library plugins at runtime
Security-focused: committed to OpenSSF best practices; see the OpenSSF Scorecard and Best Practices badge
Widely available: packaged for major Linux distributions, Conda, Spack, Homebrew, and vcpkg; validated on U.S. DoE supercomputers including Frontier, Summit, and Perlmutter
HDF5 VOL: existing HDF5 applications can use ADIOS2 as a backend transparently via the HDF5 Virtual Object Layer

Example

import adios2
import numpy as np

data = np.array([1.0, 2.0, 3.0, 4.0, 5.0])

# Write to a BP file
with adios2.Stream("data.bp", "w") as f:
    f.write("data", data)

# Read it back
with adios2.Stream("data.bp", "r") as f:
    for _ in f.steps():
        result = f.read("data")

print(result)  # [1. 2. 3. 4. 5.]

Install ADIOS2

Python (PyPI):

pip install adios2

From source: See the install documentation and scripts/runconf/runconf.sh for a CMake configuration example. Once installed, refer to Linking ADIOS2.