adk-rust

"Show me." — Ada, thirty seconds in, declining to be told about the visual builder

Episode highlights

• The Numbers — 42 crates, 4,300+ tests, 104 runnable examples, 568 μs agent-loop overhead against LangGraph's 1,228 ms
• Agents That Survive — SQLite checkpointers, delta checkpoints, and a pause that resumes in a fresh process that shares only the database file
• Subgraphs — a graph as a node, nested three deep, with channel mismatches caught when the parent compiles rather than as an absent value at run time
• Deciding At Run Time — run_node_with for work whose size comes from state, and with_goto for a node that picks its own successor with no edge declared
• Built To Run Unattended — retries with capped backoff, concurrency bounds, node timeouts, and checkpoint retention that keeps a week-long thread steady
• Governed Computer Use — approval interrupts bound to a digest, so what you approved is what runs
• What It Costs — no automatic crash recovery, an unbounded child ledger, and why we kept two orchestration APIs when the other ADKs deprecated one

Previous episodes

🎧 Episode 2: v1.0.0 — The Stable Foundation

A deep-dive into what shipped, who built it, and where it was going. 39 crates. 130K downloads. Semver stable.

▶️ Watch on YouTube — 10 min 12 sec · Hosts: James (Fenrir) & Ada (Kore)

"We believe the next generation of software will be built by composing autonomous agents, not by writing every line of logic by hand. And we believe Rust is the right language for the runtime those agents live in." — James

🎧 Episode 1: What is ADK-Rust?

2 min 21 sec · Generated entirely by ADK-Rust using Gemini 3.1 Flash TTS

How are these made?

Episodes are generated using ADK-Rust's own audio capabilities — Chirp3-HD multi-speaker TTS synthesis via adk-audio. The script, slide deck (Marp), and synthesized audio segments are concatenated with ffmpeg into a video presentation. Zero manual voice recording.

# Episode 3 assets
docs/podcast/episode-3-script.md      # Full script, eight chapters
docs/podcast/episode-3-slides.md      # Marp slide deck
docs/podcast/adk-rust-episode-3.mp4   # Final video
docs/podcast/episode-3-narration.mp3  # Audio-only

The episode 3 video and slides are not in the repository: the video alone is about 900 MB, over GitHub's 100 MB per-file limit. The script and the deck source are.

Build and test an agent in five minutes

Scaffold an OpenAI agent with the HTTP runtime:

cargo install cargo-adk
cargo adk new quickstart_agent --template api --provider openai
cd quickstart_agent
cp .env.example .env
# Open .env and replace the OPENAI_API_KEY placeholder, then:
cargo run

The server listens on 127.0.0.1:8080 (set BIND_HOST=0.0.0.0 to listen on every interface). Confirm it with:

curl -fsS http://127.0.0.1:8080/api/health

For a page where you talk to your agents, decide what they ask to do and review what they did, adk-rust serve serves the web home at http://127.0.0.1:8080/ui/: Threads, Today and Memory & rules, in light and dark.

The five-minute quickstart explains the generated files and the console-only alternative.

Add ADK-Rust to an existing project

[dependencies]
adk-rust = "3.0.0"                                        # Gemini, agents, runner, sessions
# adk-rust = { version = "3.0.0", features = ["standard"] }  # + server, auth, graph, eval

A tier is a starting point, not a ceiling. Add any single capability on top of one without moving to the next tier, so features = ["minimal", "audio"] gives you the minimal build plus audio. adk-rust/Cargo.toml lists every feature you can add this way.

One agent, end to end

use adk_rust::prelude::*;
use adk_rust::Launcher;

#[tokio::main]
async fn main() -> AnyhowResult<()> {
    dotenvy::dotenv().ok();
    let model = GeminiModel::new(&std::env::var("GOOGLE_API_KEY")?, "gemini-3.7-flash")?;

    let agent = LlmAgentBuilder::new("assistant")
        .instruction("You are a helpful assistant. Be concise and accurate.")
        .model(Arc::new(model))
        .build()?;

    Launcher::new(Arc::new(agent)).run().await?;
    Ok(())
}

Swap the provider by swapping the client. The agent, runner and tools are unchanged:

Or let it choose: adk_rust::run(instructions, input) picks a provider from the environment, among those you compiled in.

Models

Defaults are curated in adk_model::catalog and were checked on 23 August 2026. Deployment-scoped providers such as Bedrock and Azure AI still require the model or deployment identifier available in your own account and region.

Use adk_model::catalog::recommended_model(provider) for ADK's portable default, MODEL_CATALOG for user-facing pickers, and validate_model_selection when accepting configuration. Unknown IDs remain valid for private deployments and new releases; known retired IDs include an actionable replacement.

What you can build

Each row links to its guide and a runnable example.

Scaffold a project

cargo install cargo-adk

cargo adk new my-agent                       # basic Gemini agent (alias for --template llm)
cargo adk new my-agent --template tools      # agent with #[tool] custom tools
cargo adk new my-agent --template rag        # RAG with vector search
cargo adk new my-agent --template api        # REST server
cargo adk new my-agent --template graph      # graph workflow with checkpoints
cargo adk new my-agent --template realtime   # realtime voice agent
cargo adk new my-agent --template agent-engine # Gemini Enterprise Agent Engine BYOC
cargo adk new my-agent --template harness    # governed harness: REPL with approvals, AGENTS.md, skills
cargo adk new my-site --template website     # AWP 2.0 website: content, theme, charter, data and its edge

# Compose addons with any template
cargo adk new my-agent --template tools --addon telemetry --addon sessions
cargo adk new my-agent --addon mcp --addon guardrails

cd my-agent
cp .env.example .env    # add your API key
cargo run

Agent types — the core agent structure.

Enterprise patterns — pre-composed, several capabilities already wired together.

Addons — composable with any template, and with each other.

cargo adk build compiles the project without deploying, and cargo adk validate checks an agent definition without building. cargo adk templates and cargo adk addons print these lists.

Crates

Retired and extracted repos: adk-ui is retired in favour of adk-surface's genui feature (Agent-Drawn UI), and adk-studio is retired in favour of the workflow observer; adk-playground holds more examples.

Performance

Measured with cargo adk bench in June 2026, same model, workload, and prompt for every framework.

Cold start is process launch to first API call. Overhead is turn time minus the LLM round trip. Apple M-series, macOS, June 2026. Run it yourself with cargo adk bench --dry-run to see the cost estimate first.

Develop

devenv shell            # reproducible toolchain, or ./scripts/setup-dev.sh
make build              # cargo build --workspace
make test               # cargo nextest run --workspace
make clippy             # -D warnings

AGENTS.md documents the conventions CI enforces, including the per-platform tool matrix and the CI cost tiers. CONTRIBUTING.md covers the workflow and the required checks.

Documentation

• Official docs — guides for every capability above
• Wiki — tutorials and quickstarts
• docs.rs — API reference
• Examples — 148 standalone crates, plus more in the playground

Companion projects

Project

• ROADMAP.md — v3.0.0 (release candidate). Longer-term direction and why both orchestration APIs are supported
• CHANGELOG.md — every release
• CONTRIBUTORS.md — the people who built this
• STABILITY.md — crate stability tiers and the deprecation policy
• Discussions — ideas and questions

Related: Google's ADK · MCP · Gemini API

Sponsors

ADK-Rust is Apache 2.0 and developed in the open. Sponsorship pays for the CI minutes, model-provider credits, and benchmark hardware the project runs on.

Thank you to our sponsors:

Become a sponsor — monthly tiers from $5, or a one-off contribution. Sponsors are listed here and on the sponsors page.

Star History

License

Apache 2.0. See LICENSE.