---
title: "tool si.read.market_twin"
description: "Reads one market twin, and the date to read it as of: The answer gives the twin: the model family and template it was instanced from, the participants placed on the chain, the level of every stock as of the date, the simulations run on it in order, and the strategy whose armed plays are its interventions."
section: reference
address: /reference/tools/si-read-market_twin
contract: 0476e35e6e275db5
---

# tool si.read.market_twin

Reads one market twin, and the date to read it as of: The answer gives the twin: the model family and template it was instanced from, the participants placed on the chain, the level of every stock as of the date, the simulations run on it in order, and the strategy whose armed plays are its interventions.

[figure: Over MCP, si.read.market_twin takes MarketTwinInput and returns a card whose body is MarketTwin.]

The answer gives the twin: the model family and template it was instanced from, the participants placed on the chain, the level of every stock as of the date, the simulations run on it in order, and the strategy whose armed plays are its interventions. The call needs the read grant at the brand rung.



| | |
|---|---|
| input | [MarketTwinInput](/concepts/markettwininput) |
| result | a card whose body is [MarketTwin](/concepts/markettwin) |
| read-only | yes |
| destructive | no |
| card address | `ui://scale-intelligence/cards/MarketTwin` |
| HTTP route | [`/v1/read/market_twin`](/reference/read/market_twin) |





| field | type | required | note |
|---|---|---|---|
| `twin` | `id` | yes |  |
| `as_of` | `time` | no |  |