Chat Mode is Amplify's lightweight conversation mode. It uses a very small system prompt containing only the parts necessary to talk to the AI and get great results, and it disables some skills and tools that aren't relevant to a quick back-and-forth. The goal is simple: save tokens so your API budget goes further on casual Q&A, brainstorming, and explanations.
What chat mode is for
Chat mode is the default for ad-hoc, non-project conversations — the kind where you just want to ask a question, get an explanation, or bounce an idea around. It is not a "dumber" mode; the same model and the same streaming pipeline are used. What changes is how much context Amplify injects around your message.
| Concern | Chat Mode | Agent Mode |
| System prompt | Minimal — identity + output rules only | Full — identity, skills, project context, memory, tools |
| Skills | A reduced set | All available skills |
| Tools | Core only (no inject_template, no sandbox mutation) | All tools, including sandbox + template injection |
| Token budget per turn | Low | High |
| Best for | Q&A, explanations, brainstorming | Building, editing, running code |
The minimal system prompt
In chat mode the system prompt is stripped down to the essentials. The full construction logic lives in the AI Workflow doc; in chat mode only these sections are included:
- Identity — who Amplify is and how it should format answers.
- Output rules — markdown, code fences, concise answers.
- Available tools (trimmed) — only the read-only / conversational tools.
Everything else is omitted:
<available_skills>is either empty or contains only a tiny subset.<user_memory>and<user_context>are still attached (they're small and high-value), but<project_context>is not, because chat mode is not project-scoped.- Skill-discovery instructions ("you MUST first call
list_skills…") are removed, since most skills are disabled anyway.
The result is a system prompt that's typically a few hundred tokens instead of several thousand — a direct saving on every single turn of the conversation.
Disabled skills & tools
To keep the token budget low, chat mode disables capabilities that only make sense when you're actively building something in the sandbox.
Disabled tools
The following tools are not exposed to the model in chat mode:
inject_template— cloning a starter template into the workspace is pointless without a project.- Sandbox mutation tools (file writes, shell exec, package install) — there's no project to mutate.
list_design_systems/get_design_system— design systems are only relevant when generating UI code.
Read-only tools (web search, reading a file you attached, etc.) remain available.
Disabled skills
Heavy design and build skills are filtered out:
webapp-builder,mobile-app-development,react-native-component,react-componenthtml-page,docx(document generation)- Any
user_skills/skill taggedbuild-only
Lightweight, conversational skills (e.g.
api-integrationfor answering "how do I paginate a REST API?") stay enabled.
Why disable instead of hide?
Skills and tools are part of the system prompt. If they stayed enabled, their descriptions would be sent on every request — costing tokens even when never invoked. Disabling them removes their descriptions from the prompt entirely, which is where the real saving comes from.
Switching to Agent mode mid-chat
You are not locked into chat mode. If the conversation grows beyond a simple Q&A — you want the AI to actually write and run something — you can switch to Agent Mode mid-chat.
When you switch:
- The chat system prompt is replaced by the full agent system prompt (skills, project context, all tools).
- Your message history is preserved — the AI keeps the full conversation context and continues as if nothing happened, just with more capabilities available.
- Only the system prompt changes; the back-and-forth you already had is not re-sent or summarised, so there is no context loss.
This makes chat mode a great starting point: begin cheap, and escalate to the full agent only when the task demands it.
Not available in project chats
The chat ↔ agent toggle is not available in Project Chat. Project conversations always run in agent mode because project context, skills, and sandbox tools are mandatory for working on a codebase.
When to use chat mode
When you just need answers
Quick questions, explanations, comparing options, debugging concepts — no code needs to run.
When tokens matter
Long conversations on a tight API budget. The minimal prompt compounds savings across dozens of turns.
As a starting point
Start cheap, escalate to the full agent the moment you need the AI to build or run something.
Continue to Agent Mode