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Every agent in Twin operates in one of two modes: Build or Run. Understanding the difference is key to using Twin efficiently.

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Overview

Build Mode

Creating or updating an agent. Twin uses high-reasoning AI to interpret your goal, plan the steps, and generate the automation logic.

Run Mode

Executing a deployed agent. Twin uses a low-reasoning model that leverages the agent’s memory from previous builds. 12x cheaper than Build mode.

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Build Mode

Build mode is active when you’re creating a new agent or modifying an existing one through the chat editor. During a build, Twin:
  • Analyzes your natural-language instructions
  • Plans the execution steps
  • Generates the automation logic
  • Sets up integrations and navigation
  • Handles edge cases and retries
This requires the high-reasoning model, which is the most credit-intensive operation.
Build mode runs whenever you:
  • Create a brand new agent
  • Update an existing agent’s goal or logic
  • Ask the chat editor to add new steps or change behavior
You’ll always confirm whether to use high or low reasoning before a build starts — so you’re in control of the cost.

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Run Mode

Run mode is active when a deployed agent executes a task — whether triggered manually, on a schedule, or via a webhook. During a run, Twin:
  • Follows the logic established during the build
  • Uses a lightweight reasoning model
  • Leverages the agent’s memory for efficient execution
  • Costs 12x less than a build
Run mode is used whenever you:
  • Click “Run” on a deployed agent
  • A schedule triggers an agent
  • A webhook event starts an agent
  • Use the API to trigger an execution

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Cost Comparison

ModeReasoningRelative CostUsed For
BuildHigh12xCreating or updating agents
RunLow + memory1xExecuting deployed agents
Build once, run many times. The more you run a deployed agent, the more cost-efficient it becomes — each run is just a fraction of the original build cost.

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How to Tell Which Mode You’re In

The Twin interface clearly indicates the current mode: Build mode — Active in the chat editor when you’re creating or modifying an agent. You’ll see the build progress and can review the plan before it executes.
Build mode showing an agent being built
Run mode — Active when a deployed agent is executing. You’ll see the live run status, steps being performed, and results as they come in. Notice the “Runner” and “Builder” badges on each run.
Run mode showing agents with Runner and Builder badges

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What Happens at 0 Credits

When your credits run out:
  • Build mode is disabled — you can’t create or update agents
  • Run mode stays available — capped at 1 run per day
  • In-progress builds always finish — Twin never interrupts a build mid-execution

Check Your Credits

View your balance and usage breakdown