---
slug: "ReAct"
name: "ReAct"
type: "Reasoning"
layer: "Mind"
ref: "ReAct#3361"
sema_id: "sema:ReAct#mh:SHA-256:3361fd75537995da1d70c0f60b9b8bd01c44bad9e2596a81fa059b7c6c3fba83"
tags: ["Mind","Reasoning"]
updated: 2026-11-11
mindscape: "bootstrap"
index_url: https://mindscape.world/scapes/bootstrap.json
url: https://mindscape.world/bootstrap/ReAct/
related: ["Task","ToolInvoke","Agent","Chain","CognitiveBias","Loop","EventReact","sema:Reflexion#mh:SHA-256:c5b155b3053281ade32b43be8c274c6c0f1bb4315c3ec0313ce03c3c3ae97c76"]
---

# ReAct

Interleaved thought-action-observation cycle

Layer: Mind · Category: Reasoning

## Mechanism

An interleaved reasoning-action loop where the agent cycles through Thought (reason about the situation), Action (invoke a tool or take a step), and Observation (process the result). Unlike pure [Chain](https://mindscape.world/scapes/bootstrap/Chain.md)-of-Thought which reasons then answers, ReAct interleaves reasoning with environmental feedback, allowing the agent to adjust plans based on real-world results. It interleaves reasoning traces for a [Task](https://mindscape.world/scapes/bootstrap/Task.md) with [ToolInvoke](https://mindscape.world/scapes/bootstrap/ToolInvoke.md) execution, updating the context with observation results.

## Invariants

- Action based on reasoning
- Cycle of Thought-Action-Observation

## Preconditions

- Environment access
- Goal

## Postconditions

- Goal reached or deemed impossible

## Failure modes

- Observation Blindness: [Agent](https://mindscape.world/scapes/bootstrap/Agent.md) ignores observations and follows initial plan.
- [Loop](https://mindscape.world/scapes/bootstrap/Loop.md) Explosion: Endless thought-action cycles without termination.
- Action [CognitiveBias](https://mindscape.world/scapes/bootstrap/CognitiveBias.md): Jumping to actions without sufficient reasoning.

## Builds on

- [Task](https://mindscape.world/scapes/bootstrap/Task.md) (Infrastructure; Accepts)
- [ToolInvoke](https://mindscape.world/scapes/bootstrap/ToolInvoke.md) (Infrastructure; Composes with)
- [Agent](https://mindscape.world/scapes/bootstrap/Agent.md) (Mind; References)
- [Chain](https://mindscape.world/scapes/bootstrap/Chain.md) (Infrastructure; References)
- [CognitiveBias](https://mindscape.world/scapes/bootstrap/CognitiveBias.md) (Infrastructure; References)
- [Loop](https://mindscape.world/scapes/bootstrap/Loop.md) (Infrastructure; References)

## Used by

- [EventReact](https://mindscape.world/scapes/bootstrap/EventReact.md) (Mind; References)

## Identity

- Sema ID: `sema:ReAct#mh:SHA-256:3361fd75537995da1d70c0f60b9b8bd01c44bad9e2596a81fa059b7c6c3fba83`
- Ref: `ReAct#3361`
- Supersedes:
  - `sema:ReAct#mh:SHA-256:b4879d75afcfc4c7fe1d0b48f3e65b7ad2953a9b8c2a236f2cf3a2b7f98c9688`
  - `sema:ReAct#mh:SHA-256:c72018c3dbdfe960eadd257f10dfd88400a405cfd2be557977fc0e81bcae8062`
  - `sema:ReAct#mh:SHA-256:bf894b5668550ecb0031e3f015d07aa7f6023bb9fa37d89c5982b67188797bfe`
  - `sema:ReAct#mh:SHA-256:5281c82a8338b19ed33253f3447b6e845a967e6a28acb8c3efb63a6ab24ff308`
  - `sema:ReAct#mh:SHA-256:23310635be1d832c320f40f2f954751ec909e9fc7ed85314946ccbb85ef8b524`

## Links

- [Pattern page](https://mindscape.world/bootstrap/ReAct/)
- [View in the interactive graph](https://mindscape.world/bootstrap/#ReAct)
- [JSON](https://mindscape.world/scapes/bootstrap/ReAct.json)
- [Index of all patterns](https://mindscape.world/scapes/bootstrap.json)