Autonomous software engineering · for your GitHub repo
An autonomous software engineering system for building and evolving production codebases.
Descant connects to your GitHub repository and autonomously works the issues you make eligible — turning scoped engineering work into production-grade software, from the first commit of a new product to the hundred-thousandth change in a mature codebase.
Descant scored
633 of 731 real-world tasks resolved on one of the industry’s most demanding public benchmarks — ahead of every frontier model, including Mythos 5 and Fable 5. Published and reproducible.
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What Descant is
Software engineering that runs continuously.
Descant connects to your GitHub repository and autonomously works the issues you make eligible.
For each issue, it reads the surrounding code and project context, plans the change, implements it on a branch, and reviews the implementation before opening a pull request.
A separate Descant reviewer then reviews the open pull request through its own GitHub identity. The author responds to the findings and updates the pull request until the change is approved. Once approved, Descant can merge automatically or wait for a person, depending on the rules you set.
Issues, branches, pull requests, reviews, checks, and branch protections remain in GitHub.
The work does not end with the merge. Descant records durable project knowledge, documents important decisions, files separate issues for valuable work it discovers outside the current scope, and keeps the surrounding backlog current. It carries that context into future work and continuously looks for opportunities to improve its effectiveness and efficiency.
STRUCTURED EXECUTION
Each issue moves through a defined sequence: selection, planning, implementation, author review, pull request review, resolution, approval, and completion.
SEPARATE REVIEW
The pull request is reviewed through a separate Descant GitHub identity. Findings appear in the normal GitHub review workflow, where the author can respond and update the change.
REVIEW THROUGH APPROVAL
Opening the pull request begins the external review stage. Descant responds to findings and updates the change until the pull request is approved or the run is stopped.
ENGINEERING MEMORY
After completing work, Descant records durable knowledge about the codebase, important decisions, and context that future work should retain.
BACKLOG MANAGEMENT
When Descant finds valuable work outside the current scope, it files a separate issue. It also identifies duplicate or stale work and keeps the backlog around its activity organized.
CONTINUOUS IMPROVEMENT
Descant uses high-level operational signals to identify opportunities to improve engineering effectiveness, reduce repeated investigation, and use model capacity more efficiently.
YOUR EXISTING WORKFLOW
Descant works through the tools your team already uses. GitHub is supported first, with additional repository and ticketing integrations planned.
How it works
Issue by issue. System-wide.
Descant works through GitHub issues because they provide clear scope, history, and a definition of completion.
Each issue is handled as part of the larger codebase. While working, Descant updates its understanding of the project, records useful context, and creates follow-up issues for important work that falls outside the current scope.
The current issue moves the codebase forward. What Descant learns along the way improves the work that follows.
The work loop
Descant reviews and refines its implementation before opening the pull request. The open pull request is then evaluated through a separate Descant reviewer identity in GitHub.
Getting started
In practice.
Connect Descant to a GitHub repository, choose which issues it can work, and define your priorities, policies, and merge rules.
- Connect your repository. A short dashboard setup installs Descant and its reviewer on the repository you choose.
- Set your priorities and rules. Choose which issues are eligible, how work should be prioritized, and whether approved pull requests can merge automatically.
- Descant claims the next eligible issue, or works an issue you start directly.
- It plans and implements the change on a branch, reviews its work, and opens a pull request.
- A separate Descant reviewer reviews the open pull request and leaves feedback through GitHub.
- The author resolves the feedback and updates the pull request until the change is approved.
- Once approved, Descant merges automatically if enabled. Otherwise, the pull request waits for a person.
- After the work is complete, Descant records durable project knowledge, documents important rationale, files follow-up issues for work discovered outside scope, and reconciles the surrounding backlog.
Descant can also review an existing pull request, started from the dashboard. The reviewer evaluates the diff, leaves findings in GitHub, and reviews subsequent updates until the pull request is approved or the review is stopped.
When a run captures durable engineering memory, Descant commits it to your repository as a separate, reviewable pull request. Once merged, later runs can use it as project context. This preserves important decisions, reduces repeated investigation, and lowers unnecessary model usage over time.
Descant also uses high-level aggregate operational signals to improve its own effectiveness and efficiency. Customer repositories are inputs to the work, not training data for the product.
GitHub is supported first. Additional repository and ticketing integrations, including Jira, GitLab, and Bitbucket, are planned.
More than a pipeline.
Descant keeps each change focused without ignoring what it discovers elsewhere.
Breaks oversized issues into smaller units and links them back to the original tracking issue.
Keeps unrelated work out of the current pull request and files it separately.
Identifies duplicate or stale issues, reconciles completed work, and keeps newly discovered work organized.
Descant improves through high-level aggregate signals across the product, never by training on customer code. Repositories are used to perform the requested work, not as product training data.
Benchmark
Evaluated on SWE-bench Pro.
SWE-bench Pro contains 731 real-world software engineering tasks from large open-source Go, Python, JavaScript, and TypeScript projects. A task is resolved only when the submitted patch passes the benchmark’s tests in its official frozen environment.
Public SWE-bench Pro test split, 731 tasks. “Resolved” means the submitted patch passed the project’s benchmark tests in the official frozen grading environment, with no partial credit. Each figure represents that system’s end-to-end result on the same public task set. Competitor figures are published third-party results.
The complete benchmark artifact is public.
Every prediction, passing diff, resolved task, and official harness grade is available in the results repository. Clone the repository and reproduce the result.
View the reproducible results →This repository contains the benchmark results only. It does not include the Descant runtime, proprietary orchestration, prompts, or internal architecture.
Built on the frontier
A stable system around evolving models.
Descant uses frontier models as components inside a consistent software engineering system. Those models can be upgraded as the frontier advances without changing how Descant connects to your repository, works issues, reviews pull requests, or follows your approval rules.
The underlying models provide capability. Descant turns that capability into repeatable software engineering output and improves how effectively it applies that capability over time.
CLOSED BETA
Get Descant on your repo.
Descant is pre-beta, and a closed beta is opening soon. Leave your email and we'll send an invite when your spot opens.
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