Gemini Interactions API GA: Migration Checklist for Developers

Quick answer: Google says the Gemini Interactions API is now its primary interface for Gemini models and agents. If you are starting a new Gemini app, use Interactions API first; if you already have a stable generateContent integration, migrate only after checking feature gaps, storage behavior, SDK versions and production risk.

Fast migration checklist

1. Pick the right use case: choose Interactions API for agentic workflows, server-side conversation state, background execution, multimodal steps and managed agents.
2. Keep existing stable apps calm: Google says the legacy generateContent API remains supported; do not rewrite a working production app without a test plan.
3. Update SDKs: Google’s docs list Interactions API support in recent google-genai and @google/genai SDK versions.
4. Change response parsing: Interactions returns a structured steps timeline. For simple text, use SDK convenience fields such as interaction.output_text.
5. Decide on storage: interactions are stored by default for server-side state and background execution. Use store=false only when you do not need stored state or background jobs.
6. Move chat state server-side: replace client-side chat history arrays with previous_interaction_id where appropriate.
7. Use background jobs carefully: set background=true for long-running work, then retrieve the interaction status/result later.
8. Re-test tools: validate function calling, tool results, streaming and multimodal input because the new API exposes intermediate steps differently.
9. Check limitations before production: Google’s documentation may still show caveats/limitations on some pages, so verify the current docs before moving critical workloads.

What changed?

Google’s announcement describes Interactions API as a single unified endpoint for Gemini models and agents with server-side state, background execution, tool combination and multimodal generation. Google says the release adds a stable schema and major capabilities such as Managed Agents, background execution, tool improvements, Deep Research upgrades and media generation support.

For builders, the practical shift is simple: instead of treating every model response as a one-off content generation call, you can treat a model or agent run as an Interaction with a timeline of steps. That is useful for debugging agent behavior, resuming long tasks, combining tools and handling multimodal outputs.

generateContent vs Interactions API

Need	Better fit	Why
Simple existing text/image call already working	generateContent can stay	Google says it remains supported, so migration is not mandatory for every existing app.
New agentic app	Interactions API	Designed for agents, tools, stateful workflows and step timelines.
Long-running task	Interactions API	Supports background=true and later retrieval.
Multi-turn conversation without resending all history	Interactions API	Uses previous_interaction_id for server-side state.
Debugging tool calls and intermediate events	Interactions API	Returns structured steps such as user input, model output, function calls and function results.

Python starter pattern

Google’s migration guide shows the basic shape of the new call. The simple version is:

from google import genai

client = genai.Client()

interaction = client.interactions.create(
    model="gemini-3.5-flash",
    input="Summarize this customer support thread in 5 bullets."
)

print(interaction.output_text)

Stateful chat pattern

For multi-turn work, store the first interaction ID and pass it into the next call:

first = client.interactions.create(
    model="gemini-3.5-flash",
    input="My app sells fitness meal plans. Remember that context."
)

second = client.interactions.create(
    model="gemini-3.5-flash",
    previous_interaction_id=first.id,
    input="Write 3 onboarding email subject lines."
)

print(second.output_text)

Implementation notes for businesses

• Privacy: review Google’s storage and retention behavior before sending customer data. If you do not need stored state, evaluate store=false.
• Reliability: keep a fallback path for production jobs during migration.
• Observability: log interaction IDs, status, model ID, latency and tool failures.
• Cost: long-running agentic workflows can be more useful, but they can also consume more tokens/tool calls. Test with real examples before rollout.
• Human review: for customer-facing, legal, medical, financial or immigration content, keep human approval in the workflow.

FAQ

Is Gemini Interactions API replacing generateContent?

Not immediately. Google’s announcement says Interactions API is now the default/recommended interface for new projects, while generateContent remains supported.

Should I migrate today?

Migrate first if you need agents, server-side state, background execution or detailed step timelines. If your existing production integration is simple and stable, test the migration in staging before changing live systems.

What is the biggest code change?

The response is no longer just a candidate/content object. Interactions returns an interaction resource with steps. Use convenience properties for simple outputs, but inspect steps for tools, images, audio and debugging.

Can Media87 help implement this?

If your business is building AI workflows for marketing, support, internal automation or content operations, this is a natural place to prototype a controlled agent workflow before full deployment.

Sources

• Google Blog: Interactions API general availability announcement
• Google AI for Developers: Interactions API documentation
• Google AI for Developers: migration guide
• Google AI for Developers: Interactions API reference

Note: This guide is based on public Google documentation checked on July 7, 2026. API behavior, model availability and SDK versions can change; verify the latest Google docs before deploying critical production code.