# Vertex AI Agent Builder vs SOAT: Feature Comparison

> Vertex AI Agent Builder and SOAT compared on 15 agent capabilities, 8 vs 12 native, each rating linked to its source.

# SOAT vs Vertex AI Agent Builder

Vertex AI Agent Builder is a managed agent platform (Proprietary (ADK is Apache-2.0), managed). SOAT is agent infrastructure (Apache-2.0, self-hosted). Of the 15 capabilities the [benchmark](/benchmark) tracks, Vertex AI Agent Builder covers 8 natively and SOAT 12.

## At a glance

| | Vertex AI Agent Builder | SOAT |
| --- | --- | --- |
| Type | a managed agent platform | agent infrastructure |
| License | Proprietary (ADK is Apache-2.0) | Apache-2.0 |
| Deployment | managed | self-hosted |
| Native capabilities | 8 of 15 | 12 of 15 |
| Last verified | 2026-08-14 | 2026-08-14 |

## Where each one leads

- **Vertex AI Agent Builder** is native where SOAT is not: code execution.
- **SOAT** is native where Vertex AI Agent Builder is not: identity & governance, data & secrets, human-in-the-loop, multi-tenancy, declarative deployment.

## What Vertex AI Agent Builder is

Google Cloud's managed platform for building and deploying agents: Agent Development Kit, managed Agent Engine runtime, RAG Engine, and Google Cloud IAM, billing, and observability. [Vertex AI Agent Builder documentation](https://cloud.google.com/products/agent-builder).

## Capability by capability

### Agent runtime

_Agent loop, sessions, and generation lifecycle._

- **Vertex AI Agent Builder: Native.** Agent Development Kit plus the managed Agent Engine runtime with sessions. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/agent-engine/overview))
- **SOAT: Native.** Agents, sessions, chats, and generations with full lifecycle tracking. ([source](https://soat.ttoss.dev/docs/modules/agents))

### Orchestration

_Multi-step pipelines, workflows, and triggers._

- **Vertex AI Agent Builder: Native.** Multi-agent composition in ADK (sequential, parallel, loop agents); broader pipelines lean on other Google Cloud services. ([source](https://google.github.io/adk-docs/agents/multi-agents/))
- **SOAT: Native.** DAG orchestrations, workflow state machines, durable tasks, and triggers (manual, webhook, schedule). ([source](https://soat.ttoss.dev/docs/modules/orchestrations))

### Knowledge & memory

_Documents, embeddings, semantic search, and recall._

- **Vertex AI Agent Builder: Native.** RAG Engine and Vertex AI Search for grounding; Memory Bank for session memory. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/rag-overview))
- **SOAT: Native.** Documents with per-chunk embeddings, named memories, unified semantic search, and ingestion rules for PDFs, images, and audio. ([source](https://soat.ttoss.dev/docs/modules/knowledge))

### Tools & integration

_Tool calling, MCP, providers, and webhooks._

- **Vertex AI Agent Builder: Native.** Function tools, MCP support, and prebuilt connectors to Google and third-party systems. ([source](https://google.github.io/adk-docs/tools/))
- **SOAT: Native.** HTTP, MCP, client, and agent-to-agent tools; model routes with failover; webhooks; any LLM provider. ([source](https://soat.ttoss.dev/docs/modules/tools))

### Identity & governance

_IAM, guardrails, approvals, quotas, and audit._

- **Vertex AI Agent Builder: Partial.** Google Cloud IAM, quotas, and audit logging — cloud-level, not agent-action-level; no built-in guardrail/approval queue for tool calls. ([source](https://cloud.google.com/vertex-ai/docs/general/access-control))
- **SOAT: Native.** AWS-inspired IAM, actors, scoped API keys, guardrails, human approvals, quotas, and an append-only audit log. ([source](https://soat.ttoss.dev/docs/modules/iam))

### Observability

_Traces, activity, usage, and failure queues._

- **Vertex AI Agent Builder: Native.** Cloud Trace/Logging integration and Agent Engine tracing of agent runs. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/agent-engine/manage/tracing))
- **SOAT: Native.** Traces of every tool call and model response, activity feed, usage/cost tracking, and an exceptions queue. ([source](https://soat.ttoss.dev/docs/modules/traces))

### Data & secrets

_File storage and encrypted secrets._

- **Vertex AI Agent Builder: Partial.** Via adjacent Google Cloud services (Cloud Storage, Secret Manager) rather than the agent platform itself. ([source](https://cloud.google.com/secret-manager/docs/overview))
- **SOAT: Native.** File storage over local/S3/GCS backends and encrypted secrets storage. ([source](https://soat.ttoss.dev/docs/modules/files))

### Evaluation

_Datasets, scorers, and eval-gated improvement._

- **Vertex AI Agent Builder: Native.** Vertex AI evaluation service with agent-specific evaluation flows. ([source](https://cloud.google.com/vertex-ai/generative-ai/docs/models/evaluation-overview))
- **SOAT: Native.** Datasets, scorers, and scored runs; eval-gated promotion of agent versions. ([source](https://soat.ttoss.dev/docs/modules/evaluations))

### Channels

_Built-in gateways to messaging platforms and UIs._

- **Vertex AI Agent Builder: Partial.** Chat-platform delivery through Conversational Agents (Dialogflow) channel integrations, adjacent to Agent Builder itself. ([source](https://cloud.google.com/dialogflow/cx/docs/concept/integration))
- **SOAT: Absent.** Surfaces are REST, MCP, CLI, and SDK — no built-in gateways to messaging platforms like Slack, WhatsApp, or Telegram.

### Code execution

_Sandboxed code or terminal runtimes for agents._

- **Vertex AI Agent Builder: Native.** Built-in code execution tooling in ADK and the Vertex AI code interpreter extension. ([source](https://google.github.io/adk-docs/tools/built-in-tools/))
- **SOAT: Absent.** Tool types are HTTP, MCP, client, and agent-to-agent — no built-in sandboxed code or terminal runtime.

### Human-in-the-loop

_Pausing a run for human approval, then resuming it._

- **Vertex AI Agent Builder: Partial.** Agents on Agent Engine can pause through framework-level checkpoint breakpoints and resume on the same thread, but the platform provides no managed approval queue or tool-call gate. ([source](https://docs.cloud.google.com/gemini-enterprise-agent-platform/scale/runtime/use-a-langgraph-agent))
- **SOAT: Native.** Approvals are a first-class human-decision queue with frozen evidence, and guardrails classify each tool call so risky actions pause for a decision. ([source](https://soat.ttoss.dev/docs/modules/approvals))

### Multi-tenancy

_Projects or workspaces scoping resources and permissions._

- **Vertex AI Agent Builder: Partial.** Isolation comes from generic Google Cloud project-level and per-resource IAM bindings, with no agent-specific tenant, workspace, or namespace construct. ([source](https://docs.cloud.google.com/gemini-enterprise-agent-platform/machine-learning/general/access-control))
- **SOAT: Native.** Projects are multi-tenant namespaces scoping every resource, with IAM policies and quotas enforced per project. ([source](https://soat.ttoss.dev/docs/modules/projects))

### Declarative deployment

_Templates that provision agent resources as one stack._

- **Vertex AI Agent Builder: Partial.** Agent deployment is documented as suitable for generic tools such as Terraform, but there is no first-party agent template format with its own plan/apply and dependency graph. ([source](https://docs.cloud.google.com/gemini-enterprise-agent-platform/scale/runtime/deploy-an-agent))
- **SOAT: Native.** Formations provision providers, memories, tools, agents, orchestrations, and webhooks from one template, resolving refs into a dependency graph with tracked operations. ([source](https://soat.ttoss.dev/docs/modules/formations))

### Versioning & rollout

_Agent versions, canary rollout, gated promotion._

- **Vertex AI Agent Builder: Native.** Updating versioned fields creates an immutable revision with active and deprecated states, and traffic percentages can be split across active revisions for canary rollout and rollback. ([source](https://docs.cloud.google.com/gemini-enterprise-agent-platform/scale/runtime/manage-revisions-and-traffic))
- **SOAT: Native.** Every config change is archived as an append-only agent version, with canary rollout to a slice of traffic and eval-gated promotion. ([source](https://soat.ttoss.dev/docs/tutorials/agent-versioning-and-canary-rollout))

### Skill learning

_Agents authoring reusable skills from their own experience._

- **Vertex AI Agent Builder: Absent.** No first-party mechanism for an agent to author or refine reusable skills from its own experience.
- **SOAT: Absent.** Memories and knowledge store retrievable context, but agents do not author or refine reusable skills from their own experience.

## How this is rated

Each rating comes from the public documentation linked beside it: **Native** is built in, **Via plugin** needs an add-on, **Partial** covers part of the capability, **Absent** is not offered. Every solution side by side is on the [benchmark](/benchmark). A rating that is out of date is a bug: [open an issue](https://github.com/ttoss/soat/issues).