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.dev20250811171539

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.dev20250811171539
File
tesseract_decoder-0.1.1.dev20250811171539-py312-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl Python 3.12 none Linux glibc 2.39+ x86-64, Linux glibc 2.17+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-py312-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl Python 3.12 none Linux glibc 2.35+ x86-64, Linux glibc 2.17+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-py312-none-macosx_11_0_arm64.whl Python 3.12 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250811171539-py312-none-macosx_10_13_x86_64.whl Python 3.12 none macOS 10.13+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-py311-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl Python 3.11 none Linux glibc 2.17+ x86-64, Linux glibc 2.39+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-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.dev20250811171539-py311-none-macosx_11_0_arm64.whl Python 3.11 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250811171539-py311-none-macosx_10_13_x86_64.whl Python 3.11 none macOS 10.13+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-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.dev20250811171539-py310-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl Python 3.10 none Linux glibc 2.35+ x86-64, Linux glibc 2.17+ x86-64 Details
tesseract_decoder-0.1.1.dev20250811171539-py310-none-macosx_11_0_arm64.whl Python 3.10 none macOS 11.0+ ARM64 Details
tesseract_decoder-0.1.1.dev20250811171539-py310-none-macosx_10_13_x86_64.whl Python 3.10 none macOS 10.13+ x86-64 Details

Total release size: 39.1 MB

Release files / tesseract_decoder-0.1.1.dev20250811171539-py312-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
2971b166a28e64197ca444dcaca30957ea49bf05bc871e379e515634fffa761d
BLAKE2b-256 checksum
How to use checksums
f19117dfa879f38ced88ff5fdcb148c60a661a9518505cc66622e7f7aa2a5381
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.dev20250811171539-py312-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
fef50be1093a7c9aeabd39a94cd673948b8d36cfbbcadcb60de8d60e7cb169d3
BLAKE2b-256 checksum
How to use checksums
dd001039e327b196e6ebd62d418cff7a985cb7c80229e9212628fa89a3d625e6
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.dev20250811171539-py312-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
469f7d1dc7f5420fbbad45d6b8ebd449818f27291fc721ddb5ab12f249268aeb
BLAKE2b-256 checksum
How to use checksums
a3259bdf5c072156fa4ea44bcce8478300d18c04b25165f955d7adc00fd38cd2
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.dev20250811171539-py312-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
81cd7e7575d5cd0cf1c9793af9855c2ffee2234584373cf8576e9f990a31ca3f
BLAKE2b-256 checksum
How to use checksums
95d17ece318bcfff0c7eaac10d6c9be81d349f627766489c10f844741a00ad25
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.dev20250811171539-py311-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
569bc863a1267230c96209756f83bf8b419f48268a87072b8c071903de5166fe
BLAKE2b-256 checksum
How to use checksums
aa57ca4f861e7a07d6687b294fd2df747ed062b9651b4d1973db6e4e295439ee
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.dev20250811171539-py311-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
a6abb92c4045e802792aa36513f9e05d3a176b724f9635afc110ddb804d2daad
BLAKE2b-256 checksum
How to use checksums
202dab2a1e6e572f3a0c721c8b201a765d394ae608c513a842bba0f0038fe94c
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.dev20250811171539-py311-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
fceef1b58e3b56677863c236c9cad7fe9ce72aab2dd7a188805db07bc02e908f
BLAKE2b-256 checksum
How to use checksums
faaf8afeb004e991062222570bf489e9990d3fa83917714a4d8afc19ba473662
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.dev20250811171539-py311-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
214ca829c9682674efe7c37ee39bec87faef17ef322f7708c8b44074161c9a18
BLAKE2b-256 checksum
How to use checksums
4a86c38ab2f91775607e0806a551e88a9c5f486dd67f8ba20861336676e5d140
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.dev20250811171539-py310-none-manylinux_2_39_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
d8c0a312db733aef3187960079c5b3f0224508a858613b4cfeb7fb6693ed2a1f
BLAKE2b-256 checksum
How to use checksums
2f48f4be65676831b31c2fd7e568a6f8eb4456384ddf1014999076898c98ede3
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.dev20250811171539-py310-none-manylinux_2_35_x86_64.manylinux2014_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
35683d2f149f2d610d02a03785056ee161409af74f8e9d976fd8031cf308de9c
BLAKE2b-256 checksum
How to use checksums
66734b13c163fc3ab7ac1997f979e05410567339b0b2e13e0dcb059f31510d1e
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.dev20250811171539-py310-none-macosx_11_0_arm64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
006ec29dd7d091be604cb9fb48963caa3ca21aeac87e7c9dc1cb1ce5731851cb
BLAKE2b-256 checksum
How to use checksums
018fa790799d1abaf30da2e8cbb24a6dc96c44d92d6f312e948e4c7f31773f5d
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.dev20250811171539-py310-none-macosx_10_13_x86_64.whl

Download URL tesseract_decoder-0.1.1.dev20250811171539-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
61567a97767710d9c0c90d3a7ba4b5219c4bdd2df361546e305fe92d922d8673
BLAKE2b-256 checksum
How to use checksums
d056b42dfbbc15bbba152d05a78429abaee473b82226a40fc6a9520470548f7c
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