Vapi (voice agents) alternatives

Voice agents. Externalises memory from LLM into structured call state — variables rather than model recall — reducing hallucinations. Squad mode passes context across multi-agent assistant hand-offs in same call. Full Vapi (voice agents) record →

  1. 1 OpenAI Agents SDK Memory Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same conflict handling (overwrite) · same memory unit (fact) · also self-hostable · also offered managed

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 29k released 2026-10-15 MIT Compare with Vapi (voice agents) →

  2. 2 Google ADK Memory Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same conflict handling (overwrite) · same memory unit (fact) · also self-hostable · also offered managed

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 21k released 2026-08-07 Apache-2.0 Compare with Vapi (voice agents) →

  3. 3 Relevance AI Memory Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same conflict handling (overwrite) · same memory unit (fact) · also offered managed · also has MCP

    OSS ? Self-host — Managed ✓ MCP ✓ Compare with Vapi (voice agents) →

  4. 4 CrewAI Memory Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same memory unit (fact) · also self-hostable · also offered managed · also has MCP

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 51k released 2026-10-14 MIT Compare with Vapi (voice agents) →

  5. 5 LangGraph Persistence Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same memory unit (fact) · also self-hostable · also offered managed · also has MCP

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 43k released 2026-10-16 MIT Compare with Vapi (voice agents) →

  6. 6 Agno (Phidata) Memory Framework-embedded memory

    also in Framework-embedded memory · same retrieval (injection) · same conflict handling (overwrite) · same memory unit (fact) · also self-hostable · also offered managed · also has MCP

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 43k released 2026-10-21 Apache-2.0 Compare with Vapi (voice agents) →

  7. 7 LangMem (LangChain) Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same memory unit (fact) · also self-hostable · also offered managed · also has MCP

    OSS ✓ Self-host ✓ Managed ✓ MCP ✓ ★ 1.6k released 2025-10-27 MIT Compare with Vapi (voice agents) →

  8. 8 Retell AI Framework-embedded memory

    also in Framework-embedded memory · same storage (kv) · same retrieval (injection) · same memory unit (fact) · also self-hostable · also offered managed · also has MCP

    OSS ? Self-host ✓ Managed ✓ MCP ✓ Compare with Vapi (voice agents) →

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.