#Google ADK
Articles about Google ADK — exploring patterns, best practices, and real-world implementations in production systems.
26 posts tagged with google adk. ← All posts
The reference capstone for the 26-part series — every canonical ADK term, defined concisely.
The capstone of the series: every core ADK concept defined in one place — agents and orchestration, tools, sessions/state/memory, context and callbacks, runtime and streaming, models, grounding, evaluation, protocols, and deployment.
How ADK's config loader turns a declarative YAML file into a fully-built agent — and why treating an agent as data changes who gets to edit it.
Defining an agent declaratively in YAML and loading it via from_config — the loader reads, resolves, and validates the config into a built agent, so config-as-data works without writing code.
How caching a large, stable prompt prefix cuts latency and cost — and the ADK config that decides when it pays off.
Context caching cuts latency and cost by caching large, stable context — system prompt, reference docs, tool definitions — so repeated calls don't re-send and re-process the same tokens.
Post 23 of 26 in "Google ADK, Concept by Concept" — how a planner turns one-shot answers into inspectable plan-then-act reasoning.
Structuring an agent's reasoning: planners that make the model plan-then-act (ReAct-style), the built-in thinking feature, and how a planner improves multi-step tool use over naive prompting.
How ADK closes the write-code, run-it, read-the-output loop — and why "unsafe" is a warning, not a typo.
Letting an agent write and run code: built-in and container-based code executors, safe sandboxed execution, how results flow back into the conversation, and the security tradeoffs.
How ADK skills bundle instructions, tools, and resources into folders an agent can browse and load on demand.
Skills package reusable capabilities — instructions, tools, resources, including file-based skills — so they can be discovered and attached to agents, promoting reuse across projects.
cross-cutting concerns registered once on the Runner instead of copied onto every agent
Plugins are cross-cutting hooks that apply globally across every agent, tool, and runner — logging, policy, metrics, caching — as opposed to per-agent callbacks. When a plugin beats a callback.
How ADK's model abstraction lets you swap Gemini for Claude, GPT, or Ollama without touching a line of agent code
ADK is model-agnostic: use Gemini natively or plug in Claude, GPT, or Ollama via LiteLLM and a model registry, swapping the model without changing agent code.
Post 18 of 26 in "Google ADK, Concept by Concept" — retrieval tools, grounding metadata, rendering citations, and the retrieve→augment→generate loop.
Grounding answers in real data: retrieval tools, grounding metadata returned with responses, rendering citations from that metadata, and the retrieve-augment-generate RAG pattern in ADK.
Two open protocols that let an agent reach outside its own process — one to borrow tools, one to call other agents as peers.
Two interoperability protocols: MCP lets an agent consume tools from external servers, and A2A — HTTP for agents — lets one agent discover and call another remote agent as a peer over HTTP.
Stack the guardrails — callbacks, model filters, restricted tools, and clean-room sandboxing — so that if one layer misses, the next one catches
Layered defense-in-depth for agents: input/output guardrails via callbacks, Gemini safety settings, restricting tools, and sandboxing untrusted actions.
How OpenTelemetry traces, structured logs, and token metrics turn an agent's event stream into something you can debug in production.
Seeing inside a running agent: OpenTelemetry tracing with spans for agent, model, and tool steps, structured logging, and exporting traces to debug latency and tool-call trajectories.
How `adk deploy` builds, pushes, and ships an agent in a single step — and the ack-after-invocation rule that keeps event-driven agents reliable.
Deploying an agent: adk deploy with its cloud_run and agent_engine subcommands, containerizing the app, and reliability rules like ack-after-invocation so failures are redelivered, not dropped.
How ADK turns "did the agent behave correctly?" into a number you can gate a merge on.
Measuring agent quality: eval sets, scoring both the trajectory (right tools, right order) and the final response, criteria configs, and the adk eval CLI — a Python-first workflow today.
token streaming, the accumulate-and-reconcile consumer pattern, and full-duplex live streaming for voice
Consuming output as it is produced: partial events and token streaming, the accumulate-and-reconcile consumer pattern, and bidi/live streaming for voice and interactive UIs.
How an agent actually runs — a Runner drives an invocation and hands you back a stream of events, not a single answer.
How ADK runs an agent: the Runner drives an invocation that yields a stream of Event objects — content, tool calls, state deltas, control signals. The event loop explains streaming, callbacks, and state.
before/after the agent, model, and tool steps — and the single short-circuit rule that turns them into guardrails
Callbacks are lifecycle hooks around the agent, model, and tool steps — before/after each — used for guardrails (short-circuit by returning a response), logging, and mutating requests and responses.
ReadonlyContext, CallbackContext, ToolContext, InvocationContext — and why the read-only vs mutable distinction is a feature, not a limitation.
The context objects ADK passes into tools and callbacks — InvocationContext, ToolContext, CallbackContext, ReadonlyContext — what each exposes and why the read-only vs mutable split matters.
Session state is for small text and JSON. When your agent produces a PNG, a PDF, or a WAV, it belongs in the artifact store — binary-native, versioned, and out of the session record.
Artifacts are binary/file data agents produce or consume: ArtifactService saves and versions named artifacts, loaded and saved via context, keeping large blobs out of session state.
State remembers things inside one chat; Memory is the searchable archive that lets an agent recall what you told it weeks ago.
Memory is long-term recall across sessions, distinct from per-session state: MemoryService stores and retrieves prior context, surfaced via a recall tool so an agent remembers a user over time.
A `Session` is the conversation; `state` is the key-value bag agents and tools read and write — and the prefix on a key decides how long it lives.
A Session holds a conversation; state is a scoped key-value store (session/user/app/temp) read and written by tools, injected into instructions via {state} templating, and persisted by SessionService.
How a plain function becomes a callable tool, how ToolContext reaches session state, and how long-running tools pause a run for a human.
Tools give agents capabilities: a plain function becomes a tool with its signature as the schema, plus ToolContext, built-in tools, and long-running/human-in-the-loop tools across Python and Go.
How one agent routes work to specialists — and why the description field is the most important string you write.
Agent hierarchies and LLM-driven delegation: sub_agents, how the description field drives auto-transfer, and coordinator/dispatcher patterns — contrasted with deterministic workflow agents.
When you want fixed control flow, don't ask the model — wire it yourself.
Sequential, Parallel, and Loop agents compose sub-agents in fixed patterns — deterministic orchestration where you, not the model, decide control flow, with state flowing between steps.
description, instruction, generation params, and structured output — the dials on almost every agent you'll build
The four knobs on almost every ADK agent: description (for delegation), instruction with {state} templating, generation params, and structured output — Python Pydantic model vs Go genai.Schema.
An `LlmAgent`, a `Runner`, a `Session`, and a CLI that runs it all — the four pieces the other 25 concepts sit on top of.
The smallest ADK agent and the machinery around it: an LlmAgent, the Runner, a Session, and the adk CLI (adk web / adk run) that runs your agent with a dev UI or REPL — no server code.
All posts on this site are written by Pratik Dhanave, an Agentic AI Architect with 7+ years building production distributed systems, multi-agent AI platforms, and cloud-native infrastructure. About the author → Each article includes working code, architecture diagrams, and references to the specific frameworks and standards discussed. Browse all posts or explore related topics using the tag cloud above.