--- title: "How we built a Linear coding agent: the hard parts" url: https://daily.dev/posts/how-we-built-a-linear-coding-agent-the-hard-parts-kaawqy79n source_url: https://daily.dev/blog/how-we-built-a-linear-coding-agent-the-hard-parts type: article source: "daily.dev" author: "Ido Shamun" published: 2026-03-23T12:13:05.839Z updated: 2026-03-24T09:00:22.966Z tags: ["testing", "claude-code"] reading_time: 10 upvotes: 66 comments: 6 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # How we built a Linear coding agent: the hard parts **[daily.dev](https://daily.dev/sources/daily)** · [@idoshamun](https://daily.dev/idoshamun) · 10 min read · 66 upvotes · 6 comments ## Summary daily.dev built Huginn, a coding agent integrated into Linear that automates the full workflow from ticket to PR. The post covers the hard engineering problems encountered: wrapping Claude Code and Codex as child processes with their undocumented streaming formats, building a three-tier fallback parser for structured LLM output, debugging session continuity failures caused by working directory changes, and using Linear labels as a crash-resilient state machine. The team also describes their 'Digital Twin Universe' (DTU) testing approach — in-memory replicas of Linear, GitHub, and KMS running in Docker containers — which made a 99% AI-generated codebase viable. Known limitations include ongoing output parsing fragility, rough BYOK credential handling, and poor fit for tight iterative or architecturally complex tasks. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@kkurko** · 1 upvotes > Great read, thanks for sharing! I really like what Linear is doing in terms of embedding AI agents; I’m actually discussing the possibility of experimenting with this tool with my manager right now. If we decide to move in this direction, your article will be a huge help in setting up our workflow **@khauma** · 0 upvotes > Dope blog post ## Similar posts on daily.dev - [Now Linear writes the code, too](https://daily.dev/posts/now-linear-writes-the-code-too-xifbg7iwf) · Linear · 17 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#claude-code](https://daily.dev/tags/claude-code) [View this post on daily.dev](https://daily.dev/posts/how-we-built-a-linear-coding-agent-the-hard-parts-kaawqy79n)