managed-agents

A guide to managed agents in Google’s Agent Development Kit. These are Google-hosted agents whose reasoning, tools, and execution environment run through the Managed Agents API.

In plain words
What is it for?
Use it to connect a ManagedAgent to Gemini API or Agent Platform flows, either as a standalone agent or as one step inside a larger ADK workflow.
Why use it?
It lets an ADK workflow use a server-hosted specialized agent without building and operating its execution environment or declaring all its tools locally.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/google/adk-docs/managed-agents
Clone the repo
git clone --depth 1 https://github.com/google/adk-docs
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,922 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01922
Opus 5 $0.00000 $0.00961
Sonnet 5 $0.00000 $0.00384
Haiku 4.5 $0.00000 $0.00192

Measured yesterday against content hash aaab1b92598e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

managed-agents scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

docs/agents/managed-agents.md · 177 lines

How it starts

The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Managed agents

Managed agents let you use Google's first-party, out-of-the-box agents, backed by the Managed Agents API, from within your ADK flows. Managed agents are available through the Gemini API and Agent Platform. The ManagedAgent class connects to a managed agent (such as the Antigravity agent) that runs in a specialized, server-side execution environment, so you get powerful built-in capabilities without managing sandboxes or writing client-side function declarations.

ManagedAgent implements the same BaseAgent contract as other ADK agents, so you can use it standalone or drop it directly into an ADK flow. It is a good fit when you want a robust, server-hosted agent with specialized built-in tools rather than building and operating that environment yourself.

What are managed agents?

A managed agent is an agent whose reasoning, tools, and execution environment are hosted and operated by Google through the Managed Agents API, rather than run by your own ADK process. Instead of issuing standard generate_content calls, ManagedAgent creates server-side interactions and streams the results back into your ADK flow. Managed agents provide several built-in advantages:

  • First-party, out-of-the-box agents: Connect to ready-made agents (for example, the Antigravity agent) by referencing their agent_id.
  • Built-in, server-side execution: Capabilities such as web search and code execution run in a managed sandbox on the server, with no local sandbox to provision or secure.
  • No client-side function declarations: Server-side tools are configured on the managed agent, so you don't declare or execute them locally.

When to use managed agents vs. building your own

Read the full file on GitHub · 177 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 177 lines · 0 tokens per session scan A aaab1b92598e

Subscribe to this mod's changes

managed-agents is an agent published in the GitHub repository google/adk-docs (1,479 stars, last pushed 3d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,922 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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