Vapi vs Agent.so

Vapi runs phone agents that answer support lines, qualify leads, schedule appointments, and place outbound sales calls with sub-500ms response times. Engineering teams configure voice, conversation flow, telephony, and integrations in one platform that has handled over one billion calls for customers including Amazon Ring, Intuit, and ServiceTitan.

Building phone agents usually means stitching together telephony, speech-to-text, an LLM, text-to-speech, and call routing yourself. Vapi bundles those layers with squads, warm transfers, live tool calling, MCP access, and 200+ model integrations so engineering teams ship production voice flows through one API instead of five vendors.

Vapi targets engineering teams shipping production voice agents and enterprises that need compliance, uptime guarantees, and dedicated support. Scale customers get SSO, RBAC, SOC 2, HIPAA, PCI, data residency, and a dedicated account team.

Agent.so puts hundreds of role-specific AI agents and a custom agent builder behind one login. You chat with pre-built experts spanning marketing, coding, tutoring, and dozens of other fields, create your own agents in seconds without code, and train them on your files, links, and sitemaps. The platform routes chats through models from OpenAI, Anthropic, Google, Meta, xAI, DeepSeek, and other labs so you are not tied to a single chatbot subscription.

Most agent builders hand you a blank canvas and expect you to wire prompts yourself. Agent.so front-loads the library with 250+ ready-made agents, an Apps Hub for one-shot tasks like subject lines and ad copy, and a Shards currency for pay-as-you-go access to advanced models and skills. That structure suits people who want specialist chats on day one rather than a week of setup.

Freelancers, consultants, and small teams use Agent.so for marketing drafts, coding help, and training agents on client knowledge bases. Agent Plus costs $19 per month at the early-access rate (regular $29) and includes unlimited messages, custom agent training, and 3,000 monthly Shards. A free tier remains available with conversation depth limits and caps on how many custom agents you can run at once.