# Vercel Open-Sources durable-harness for Crash-Proof Coding Agents

DevFeed: [Vercel Open-Sources durable-harness for Crash-Proof Coding Agents](<https://devfeed.tech/articles/vercel-open-sources-durable-harness-for-crash-proof-coding-agents-94009.md>)

Original publisher: [Read original article](<https://www.marktechpost.com/2026/10/21/vercel-durable-harness-crash-proof-coding-agents/>)

Author: Michal Sutter

Published: 2026-10-21T22:15:39Z

Content type: article

Language: en

Sources: [MarkTechPost](<https://devfeed.tech/sources/marktechpost.md>)

Topics: [Agent Harness](<https://devfeed.tech/topics/agent-harness.md>), [agentic-coding](<https://devfeed.tech/topics/agentic-coding.md>), [Persistence](<https://devfeed.tech/topics/persistence.md>), [Vercel](<https://devfeed.tech/topics/vercel.md>)

Tags: [adapters](<https://devfeed.tech/tags/adapters.md>), [agentic-ai](<https://devfeed.tech/tags/agentic-ai.md>), [agents](<https://devfeed.tech/tags/agents.md>), [ai-shorts](<https://devfeed.tech/tags/ai-shorts.md>), [artificial-intelligence](<https://devfeed.tech/tags/artificial-intelligence.md>), [claude-code](<https://devfeed.tech/tags/claude-code.md>), [codex](<https://devfeed.tech/tags/codex.md>), [coding](<https://devfeed.tech/tags/coding.md>), [coding-agents](<https://devfeed.tech/tags/coding-agents.md>), [crash](<https://devfeed.tech/tags/crash.md>), [crashes](<https://devfeed.tech/tags/crashes.md>), [editors-pick](<https://devfeed.tech/tags/editors-pick.md>), [for-devs](<https://devfeed.tech/tags/for-devs.md>), [harness](<https://devfeed.tech/tags/harness.md>), [laptop](<https://devfeed.tech/tags/laptop.md>), [logs](<https://devfeed.tech/tags/logs.md>), [model](<https://devfeed.tech/tags/model.md>), [new-releases](<https://devfeed.tech/tags/new-releases.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [opencode](<https://devfeed.tech/tags/opencode.md>), [package](<https://devfeed.tech/tags/package.md>), [pi](<https://devfeed.tech/tags/pi.md>), [postgres](<https://devfeed.tech/tags/postgres.md>), [sessions](<https://devfeed.tech/tags/sessions.md>), [staff](<https://devfeed.tech/tags/staff.md>), [tech-news](<https://devfeed.tech/tags/tech-news.md>), [technology](<https://devfeed.tech/tags/technology.md>), [tool](<https://devfeed.tech/tags/tool.md>), [vercel](<https://devfeed.tech/tags/vercel.md>)

## AI overview

Vercel's experimental durable-harness logs model and tool call intents and outcomes, then resumes a turn from that log if its function crashes. Completed calls are read back rather than rerun; tools can be configured for safe replay or never to replay. Harness session files are mirrored too. Pi and OpenCode can run in the function, while Claude Code and Codex require a Vercel Sandbox. Workspaces include a networkless virtual filesystem, temporary in-memory scratch files, or a Sandbox with Drive storage. The package can run on Vercel, locally, or self-hosted with Postgres on Node.js 22+; the excerpt also lists MongoDB, Redis, and Turso. It is version 0.0.x, and Vercel has published no performance benchmarks; recovery claims are self-reported.

## Source excerpt

Vercel released durable-harness, an open-source package that logs every model and tool call so Pi, OpenCode, Claude Code and Codex sessions resume after crashes, timeouts and redeploys on Vercel, Postgres or a laptop. The post Vercel Open-Sources durable-harness for Crash-Proof Coding Agents appeared first on MarkTechPost.