Skip to main content
Pre-release

This release is a pre-release and may not be stable for production use.

Tesseract Decoder

A Search-Based Decoder for Quantum Error Correction.

Licensed under the Apache 2.0 open-source license C++

Installation – Usage – Python Interface – Paper – Help – Citation – Contact

Tesseract is a Most Likely Error decoder designed for Low Density Parity Check (LDPC) quantum error-correcting codes. It applies pruning heuristics and manifold orientation techniques during a search over the error subsets to identify the most likely error configuration consistent with the observed syndrome. Tesseract achieves significant speed improvements over traditional integer programming-based decoders while maintaining comparable accuracy at moderate physical error rates.

We tested the Tesseract decoder for:

  • Surface codes
  • Color codes
  • Bivariate-bicycle codes
  • Transversal CNOT protocols for surface codes

Features

  • A* search: deploys A* search while running a Dijkstra algorithm with early stop for high performance.
  • Stim and DEM Support: processes Stim circuit files and Detector Error Model (DEM) files with arbitrary error models. Zero-probability error instructions are automatically removed when a DEM is loaded.
  • Parallel Decoding: uses multithreading to accelerate the decoding process, making it suitable for large-scale simulations.
  • Efficient Beam Search: implements a beam search algorithm to minimize decoding cost and enhance efficiency. Sampling and Shot Range Processing: supports sampling shots from circuits. When a detection error model is provided without an accompanying circuit, Tesseract requires detection events from files using --in. The decoder can also process specific shot ranges for flexible experiment setups.
  • Detailed Statistics: provides comprehensive statistics output, including shot counts, error counts, and processing times.
  • Heuristics: includes flexible heuristic options: --beam, --det-penalty, --beam-climbing, --no-revisit-dets, --at-most-two-errors-per-detector, and --pqlimit to improve performance while maintaining a low logical error rate. To learn more about these options, use ./bazel-bin/src/tesseract --help
  • Visualization tool: open the viz directory in your browser to view decoding results. See viz/README.md for instructions on generating the visualization JSON.

Installation

Tesseract relies on the following external libraries:

  • argparse: For command-line argument parsing.
  • nlohmann/json: For JSON handling (used for statistics output).
  • Stim: For quantum circuit simulation and error model handling.

Build Instructions

Tesseract uses Bazel as its build system. To build the decoder:

bazel build src:all

Running Tests

Unit tests are executed with Bazel. Run the quick test suite using:

bazel test //src:all

By default the tests use reduced parameters and finish in under 30 seconds. To run a more exhaustive suite with additional shots and larger distances, set:

TESSERACT_LONG_TESTS=1 bazel test //src:all

Usage

The file tesseract_main.cc provides the main entry point for Tesseract Decoder. It can decode error events from Stim circuits, DEM files, and pre-existing detection event files.

Basic Usage:

./tesseract --circuit CIRCUIT_FILE.stim --sample-num-shots N --print-stats

To decode pre-generated detection events, provide the input file using --in SHOTS_FILE --in-format FORMAT.

Example with Advanced Options:

./tesseract \
        --pqlimit 1000000 \
        --at-most-two-errors-per-detector \
        --det-order-seed 232852747 \
        --circuit circuit_file.stim \
        --sample-seed 232856747 \
        --sample-num-shots 10000 \
        --threads 32 \
        --print-stats \
        --beam 23 \
        --num-det-orders 1 \
        --shot-range-begin 582 \
        --shot-range-end 583

Example Usage

Sampling Shots from a Circuit:

./tesseract --circuit surface_code.stim --sample-num-shots 1000 --out predictions.01 --out-format 01

Using a Detection Event File:

./tesseract --in events.01 --in-format 01 --dem surface_code.dem --out decoded.txt

Using a Detection Event File and Observable Flips:

./tesseract --in events.01 --in-format 01 --obs_in obs.01 --obs-in-format 01 --dem surface_code.dem --out decoded.txt

Tesseract supports reading and writing from all of Stim's standard output formats.

Performance Optimization

Here are some tips for improving performance:

  • Parallelism over shots: increase --threads to leverage multicore processors for faster decoding.
  • Beam Search: use --beam to control the trade-off between accuracy and speed. Smaller beam sizes result in faster decoding but potentially lower accuracy.
  • Beam Climbing: enable --beam-climbing for enhanced cost-based decoding.
  • At most two errors per detector: enable --at-most-two-errors-per-detector to improve performance.
  • Priority Queue limit: use --pqlimit to limit the size of the priority queue.

Output Formats

  • Observable flips output: predictions of logical errors.
  • DEM usage frequency output: if --dem-out is specified, outputs estimated error frequencies.
  • Statistics output: includes number of shots, errors, low confidence shots, and processing time.

Python Interface

Full Python wrapper documentation

This repository contains the C++ implementation of the Tesseract quantum error correction decoder, along with a Python wrapper. The Python wrapper/interface exposes the decoding algorithms and helper utilities, allowing Python users to leverage this high-performance decoding algorithm.

The following example demonstrates how to create and use the Tesseract decoder using the Python interface.

import tesseract_decoder.tesseract as tesseract
import stim

# 1. Define a detector error model (DEM)
dem = stim.DetectorErrorModel("""
    error(0.1) D0 D1
    error(0.2) D1 D2 L0
    detector(0, 0, 0) D0
    detector(1, 0, 0) D1
    detector(2, 0, 0) D2
""")

# 2. Create the decoder configuration
config = tesseract.TesseractConfig(dem=dem, det_beam=50)

# 3. Configure and create a decoder instance
decoder = tesseract.TesseractDecoder(config)

# 4. Simulate detection events and decode it
detections = [1, 2]
flipped_observables = decoder.decode(detections)

print(f"Detections: {detections}")
print(f"Flipped observables: {flipped_observables}")

Help

We are committed to providing a friendly, safe, and welcoming environment for all. Please read and respect our Code of Conduct.

Citation

When publishing articles or otherwise writing about Tesseract Decoder, please cite the following:

@misc{beni2025tesseractdecoder,
    title={Tesseract: A Search-Based Decoder for Quantum Error Correction},
    author = {Aghababaie Beni, Laleh and Higgott, Oscar and Shutty, Noah},
    year={2025},
    eprint={2503.10988},
    archivePrefix={arXiv},
    primaryClass={quant-ph},
    doi = {10.48550/arXiv.2503.10988},
    url={https://arxiv.org/abs/2503.10988},
}

Contact

For any questions or concerns not addressed here, please email tesseract-decoder-dev@google.com.

Disclaimer

Tesseract Decoder is not an officially supported Google product. This project is not eligible for the Google Open Source Software Vulnerability Rewards Program.

Copyright 2025 Google LLC.

Metadata

Release files for tesseract-decoder 0.1.1.dev20250809020229

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Built distributions (wheels)

Table of built distributions (wheels) for tesseract-decoder 0.1.1.dev20250809020229
File
tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl Python 3.12 none Linux glibc 2.17+ x86-64, Linux glibc 2.39+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl Python 3.12 none Linux glibc 2.17+ x86-64, Linux glibc 2.35+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_11_0_arm64.whl Python 3.12 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_10_13_x86_64.whl Python 3.12 none macOS 10.13+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl Python 3.11 none Linux glibc 2.39+ x86-64, Linux glibc 2.17+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl Python 3.11 none Linux glibc 2.35+ x86-64, Linux glibc 2.17+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_11_0_arm64.whl Python 3.11 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_10_13_x86_64.whl Python 3.11 none macOS 10.13+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl Python 3.10 none Linux glibc 2.17+ x86-64, Linux glibc 2.39+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl Python 3.10 none Linux glibc 2.17+ x86-64, Linux glibc 2.35+ x86-64 Details
tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_11_0_arm64.whl Python 3.10 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_10_13_x86_64.whl Python 3.10 none macOS 10.13+ x86-64 Details

Total release size: 38.9 MB

Release files / tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl
Size 3.4 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.39+ x86-64 Python 3.12
SHA-256 checksum
How to use checksums
d4232e7599d940f5a1abe2fc31b6c837016fc837828007f1b604c34ce61e020e
BLAKE2b-256 checksum
How to use checksums
a5f190a20f6ef9c4b7c08fe40a6fdd5e63e92a8ac7515caa7e6775b86745add7
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py312-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl
Size 3.5 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.35+ x86-64 Python 3.12
SHA-256 checksum
How to use checksums
892a94cfdafc2d1dcf28a268bf7c1310173a5444948c933206f0547925067a8f
BLAKE2b-256 checksum
How to use checksums
64803c025cb0f36a95248a6c6b813ac50d76aed1027a46e8924a467fdbdda9c0
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_11_0_arm64.whl
Size 3.1 MB
Tags Python 3.12 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
a87fc4e49bccb35e8db8e003cbbe04afde1d980210a638994bb779c708bcca46
BLAKE2b-256 checksum
How to use checksums
a951a22a9a9201244ec8841d725caa771d736fba5ab26d7c7cca243c5af872c9
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py312-none-macosx_10_13_x86_64.whl
Size 3.0 MB
Tags Python 3.12 macOS 10.13+ x86-64
SHA-256 checksum
How to use checksums
8649d1a5d889e51fdfa0dce90bdae48abd1d9658d4a5923ad9b5532e4cfdb2ac
BLAKE2b-256 checksum
How to use checksums
168de43c8d300a7e8e108a1e53e2d9a78c85869f0c11c63a5354e1c0d4b0a6ee
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl
Size 3.4 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.39+ x86-64 Python 3.11
SHA-256 checksum
How to use checksums
d0bd59ef14d30b4dcbd51188983c1eeca9d3d4ef2562b6240ea76bfa87c1328c
BLAKE2b-256 checksum
How to use checksums
7550b5d2a714a0597a784028f909be57ee247e036afb43972beda1e79001d77e
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py311-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl
Size 3.5 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.35+ x86-64 Python 3.11
SHA-256 checksum
How to use checksums
89764e5e7cc1fef878552da75837fd1a84b5479ff2458d2376f6a5facd8792e7
BLAKE2b-256 checksum
How to use checksums
889229528a6306bb3e16ad2dbf6e9083fdabd0a5f1876ff66f13ff0271b9fd63
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_11_0_arm64.whl
Size 3.1 MB
Tags Python 3.11 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
c6701eb763bce45cec3d1c482ff81996057e1d472c1f4f04dd79b8056a072807
BLAKE2b-256 checksum
How to use checksums
4b389deb4753a10c51eb4ec34e2b103eb6c17c6646f3717213fa8ef00272eafb
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py311-none-macosx_10_13_x86_64.whl
Size 3.0 MB
Tags Python 3.11 macOS 10.13+ x86-64
SHA-256 checksum
How to use checksums
a1a218a5b90286ebaabe1bd9eef83866c1d6efe59096ac1232fb2249b28e699e
BLAKE2b-256 checksum
How to use checksums
824416a45d326e7cea45d9a5d5e0ba964b2b5e2744e0221649f9c3ed8eaec0d0
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl
Size 3.4 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.39+ x86-64 Python 3.10
SHA-256 checksum
How to use checksums
b9a17fbeed3af4b3411c0494f2281a3ceeebc768103f8a4e993ef35610b7b505
BLAKE2b-256 checksum
How to use checksums
c071598fdd8f1542665ff4a0854600b5d7783dfbf893d0a75969298bb0a84b65
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py310-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl
Size 3.5 MB
Tags Linux glibc 2.17+ x86-64 Linux glibc 2.35+ x86-64 Python 3.10
SHA-256 checksum
How to use checksums
f4fecd3a6f0e716cadb7c5a2ade5cd9ef4c0c1bab1a0bcb19b250ab652e4ea8d
BLAKE2b-256 checksum
How to use checksums
fc9e7d895f33bb4df4433b915ff31faf5daa8134a46f73cd3809da38ebde8f2f
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_11_0_arm64.whl
Size 3.1 MB
Tags Python 3.10 macOS 11.0+ ARM64
SHA-256 checksum
How to use checksums
0e727aececf342415ca6f4edcb9b59c5e0c4e98551e4d8f1a7e3a8da4f7701de
BLAKE2b-256 checksum
How to use checksums
7c988ad3ab5d34aa394645a3d32d03a6b5673333af10829dbf64a12e36211519
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250809020229-py310-none-macosx_10_13_x86_64.whl
Size 3.0 MB
Tags Python 3.10 macOS 10.13+ x86-64
SHA-256 checksum
How to use checksums
83d9d74c2bcb2c0d71741751f6e8d9f2b47cdc364c599113ee464353522a1712
BLAKE2b-256 checksum
How to use checksums
d05bd0ccdccb196dbc9abf7d2a3d5cd167ecc329dae59ad8707a4570f4cef399
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release history Release notifications | RSS feed

This release
Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page