{"data":{"id":2357,"lang":"en","title":"OpenAI Launches Agents API in Public Beta, Exposing the Codex Harness to Developers","summary":"OpenAI's new Agents API puts its Codex agent harness behind a single API call, letting developers run long-lived, tool-using AI agents with built-in context management.","category":"ai","category_label":"AI","published_at":"2026-09-12T02:01:11Z","updated_at":"2026-09-12T02:01:11Z","url":"https://techtools.cz/tools/news/article/2357-openai-launches-agents-api-in-public-beta-exposing-the-codex-harness-to","api_url":"https://techtools.cz/news-api/v1/articles/2357?lang=en","markdown_url":"https://techtools.cz/news-api/v1/articles/2357.md?lang=en","image_url":"https://www.marktechpost.com/wp-content/uploads/2026/09/blog122-4.png","word_count":199,"reading_time_minutes":1,"sources":[{"url":"https://www.marktechpost.com/2026/09/10/openai-launches-the-agents-api-in-public-beta-putting-the-codex-harness-behind-one-api-call/","domain":"marktechpost.com"}],"translation":{"lang":"cs","id":2430,"title":"OpenAI spustilo veřejnou betu Agents API a otevřelo vývojářům přístup k jádru Codexu","url":"https://techtools.cz/tools/news/clanek/2430-openai-spustilo-verejnou-betu-agents-api-a-otevrelo-vyvojarum-pristup-k-jadru","api_url":"https://techtools.cz/news-api/v1/articles/2430?lang=cs"},"content":"OpenAI opened a public beta of its new Agents API on September 10, giving developers direct access to the managed agent infrastructure that powers Codex. A single API call now handles long-lived agent sessions, tool use via MCP and custom tools, and coordination of multiple subagents on one task.\n\nThe API is built around four concepts: an Agent (model, instructions and tools), an Environment (an optional sandbox for file access and command execution), a Session (a durable agent instance), and Events/Items covering inputs and outputs. Built-in features include automatic context compaction for long-running sessions, a tool-search mechanism that cuts token usage, and parallel programmatic tool calling. Developers can run agents in an OpenAI-hosted sandbox or self-host via `codex exec-server`, with partner integrations including Cloudflare, DigitalOcean, E2B, Modal, Oracle and Vercel.\n\nThere is no separate Agents API fee — usage is billed through the models, tools and container time consumed. OpenAI reported vendor results from early testers: Ciridae improved its evaluation score from 0.71 to 0.85 with a 4x latency reduction, SafetyKit cut its per-case cost by 60%, and Hypha saw 86% fewer failed responses. The beta currently supports only US data residency and does not support Zero Data Retention."}}