ChatGPT — Codex (cloud agent) alternatives

OpenAI's cloud-hosted, asynchronous coding agent surfaced inside ChatGPT — distinct from Codex CLI (terminal) and from the deprecated 2021 Codex API. Released 2025-05. Reads + writes from sandboxed cloud environments; integrates with GitHub. Full ChatGPT — Codex (cloud agent) record →

  1. 1 OpenHands Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same conflict handling (llm-arbitrate) · same memory unit (turn) · also offered managed

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 92k released 2026-09-25 MIT Compare with ChatGPT — Codex (cloud agent) →

  2. 2 Manus AI Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same conflict handling (llm-arbitrate) · same memory unit (turn) · also offered managed

    OSS ? Self-host — Managed ✓ MCP ? released 2026-09-28 Compare with ChatGPT — Codex (cloud agent) →

  3. 3 Cognition Devin v2 / Spec Mode Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same conflict handling (llm-arbitrate) · also offered managed

    OSS ? Self-host — Managed ✓ MCP ✓ released 2026-10-26 Compare with ChatGPT — Codex (cloud agent) →

  4. 4 JetBrains AI Assistant Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same memory unit (turn) · also offered managed

    OSS ? Self-host ✓ Managed ✓ MCP ✓ Compare with ChatGPT — Codex (cloud agent) →

  5. 5 Bedrock AgentCore (AWS) Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same conflict handling (llm-arbitrate) · also offered managed

    OSS ? Self-host — Managed ✓ MCP ✓ ★ 750 Compare with ChatGPT — Codex (cloud agent) →

  6. 6 JetBrains Junie Agent IDEs & coding harnesses

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same memory unit (turn) · also offered managed

    OSS ? Self-host — Managed ✓ MCP ✓ released 2026-10-21 Compare with ChatGPT — Codex (cloud agent) →

  7. 7 Bolt.new (StackBlitz) — harness Agent IDEs & coding harnesses ⚠ inactive — no longer developed (pivoted)

    also in Agent IDEs & coding harnesses · same storage (kv) · same retrieval (injection) · same conflict handling (llm-arbitrate) · also offered managed

    OSS ? Self-host — Managed ✓ MCP ✓ ★ 17k Compare with ChatGPT — Codex (cloud agent) →

  8. 8 Browser Use Computer-use & desktop agents

    same storage (kv) · same retrieval (injection) · same memory unit (turn) · also offered managed

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 119k MIT Compare with ChatGPT — Codex (cloud agent) →

Ranked by shared memory design (storage, retrieval, conflict handling, memory unit), same section and shared must-haves (open source, self-hosting, MCP), with adoption as a tie-breaker. ✓ confirmed · — no · ? not in the catalog yet. Want picks for your own requirements? Use the chooser. Checking a whole project? Check your stack.