{"type":"post","id":"concordat-open-source-python-library-enforces-typed-session-679072","slug":"concordat-open-source-python-library-enforces-typed-session-679072","title":"Concordat: open-source Python library enforces typed session protocols on LLM agents","description":"Concordat is an open-source Python library that makes an LLM agent follow a finite-state session protocol at runtime rather than relying on prompt instructions.","retrieval_nugget":"Concordat is an open-source Python library that makes an LLM agent follow a finite-state session protocol at runtime rather than relying on prompt instructions. Its evaluation suggests that restricting available actions can prevent skipped human confirmations without a significant loss in task success.","published_at":"2026-10-29","updated_at":"2026-10-29","record_date":"2026-10-29","date_kind":"published_at","topics":["claude"],"entities":["Concordat","Milad Sikaroudi","tau-bench","GPT-4.1","Claude Haiku 5.5"],"related_patterns":["agent-security-moves-to-runtime-boundaries","agent-ready-software-exposes-capabilities"],"novelty_label":"new_fact","what_changed":"Concordat introduces a distinct open-source library for enforcing typed session protocols on LLM agents; none of the prior documents cover this release.","prior_refs":[],"source_url":"https://arxiv.org/abs/2610.37461","source_urls":["https://arxiv.org/abs/2610.37461"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:concordat-open-source-python-library-enforces-typed-session-679072","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/concordat-open-source-python-library-enforces-typed-session-679072/","markdown":"https://newruntime.com/posts/concordat-open-source-python-library-enforces-typed-session-679072.md","json":"https://newruntime.com/posts/concordat-open-source-python-library-enforces-typed-session-679072.json"},"next_reads":[{"type":"topic","path":"/topics/claude/","url":"https://newruntime.com/topics/claude/","title":"Claude","reason":"Explore the claude topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/claude.md","json_url":"https://newruntime.com/topics/claude.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}