go-adk

Expert guidance for developing agents with google.golang.org/adk (Go ADK).

When to trigger

• The user mentions Go ADK, google.golang.org/adk, adk-go, or asks how to build agents in Go.
• The task involves ADK concepts like llmagent, tools, callbacks, sessions/state/memory, workflow agents, streaming, MCP, A2A, ADK web/API runtime, launchers, deployment, evaluation, or safety controls.

Core rules

• Treat references/llms-index.md as the required ADK coverage map.
• Target the current stable Go ADK v1.x surface; as of May 5, 2026, use v1.2.0 as the default baseline unless the repo pins an older tag.
• Prefer official ADK Go APIs, package docs, and examples over ad-hoc wrappers.
• Follow existing repository patterns first (imports, launcher style, layout, env handling).
• For version-sensitive behavior, check package docs and release/docs pages before giving definitive guidance.
• Prioritize Go-specific ADK docs first; if a feature is documented only in another SDK doc, call that out explicitly and avoid presenting it as established Go API.
• Keep agent names unique and never use user as an agent name.
• Use concise Description fields so delegation and tool selection remain reliable.
• Treat ADK Web as development-only unless the user explicitly asks for production runtime choices.
• Do not mix older pre-v1 snippets with current v1 launcher/runtime patterns in the same answer.

Workflow

1. Map task to ADK domain:
   • Build, run, deploy, evaluate, safety, components, protocols, or reference.
   • Load only the relevant sections from references/llms-index.md.
2. Confirm execution style:
   • Launcher-first app (cmd/launcher/full for local development, cmd/launcher/prod for production-facing launchers) or embedded runtime (runner.New(...) + Runner.Run(...)).
   • Local CLI, dev web UI, REST/API server, or custom service loop.
3. Build the first working agent:
   • llmagent.New(llmagent.Config{...}) with a concrete model (commonly gemini.NewModel(ctx, ..., &genai.ClientConfig{...})).
   • Add minimum viable Instruction, Description, and either Tools or Toolsets.
4. Add tools safely:
   • Use functiontool.New(...) for typed custom tools.
   • Use mcptoolset.New(...), skills, or other ADK-native integrations only when needed.
   • For sensitive tools, apply confirmations, auth, and policy callbacks; prefer tool.WithConfirmation(...) for grouped toolsets.
5. Wire stateful execution:
   • Sessions via session.Service (often session.InMemoryService() for local dev).
   • Add memory.Service only when cross-session retrieval is required.
   • Add artifact/state/context management only when required by the workflow.
6. Apply control points:
   • Use callbacks (Before/After Agent, Before/After Model, OnModelError, Before/After Tool, OnToolError) for logging, caching, guardrails, and overrides.
   • Prefer plugins for reusable security policy enforcement.
7. Scale composition:
   • Use workflow agents for deterministic orchestration (sequentialagent, parallelagent, loopagent).
   • Use multi-agent delegation (descriptions + transfer behavior) only when specialization is clear.
   • Use remote agents/A2A only when process or host boundaries are intentional.
8. Select runtime/deployment posture:
   • Local dev: full.NewLauncher() with go run agent.go, go run agent.go web api, or go run agent.go web api webui.
   • Production: prod.NewLauncher() or embedded server/runtime plus deployment target, observability, and safety posture.
9. Verify behavior end-to-end:
   • Validate happy-path conversation, tool errors, callbacks, session lifecycle, confirmation behavior, and evaluation criteria.

Output expectations

• Provide exact Go imports, runnable snippets, and command lines that match the chosen runtime mode.
• Call out version-sensitive behavior if the user targets older ADK tags or the repo mixes docs from multiple ADK generations.
• Mention the relevant ADK doc section when guidance comes from llms-index categories beyond core Go quickstart pages.
• Prefer small, testable incremental changes over large rewrites.

References

• Quickstart and launcher baseline: references/quickstart.md
• Core APIs and agent config: references/core-primitives.md
• Tools, callbacks, and guardrails: references/tools-and-guardrails.md
• Runtime modes, examples, and A2A: references/runtime-and-examples.md
• Models, versioning, and operations posture: references/models-and-operations.md
• Required ADK source map (llms.txt-derived curated index): references/llms-index.md