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LibraryCredit and stable value2020Design paperCorpus record

ERC-3156: Flash Loans

Flash loans. Alberto Cuesta Cañada, Fiona Kobayashi, fubuloubu, Austin Williams.

A flash lender sends assets to a receiver and requires that the same transaction returns them, plus a fee. If it does not, the transaction reverts. There is no default in the credit sense, because there is no time.

A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.

An oracle that can be moved and restored inside one transaction is compatible with this primitive. That is the risk to design against.
Evidence
Primary paper
Re-measured
No
Assumptions
3
Records linked
2

Code

Source, repository, and what is actually hosted

  • EIP-3156https://eips.ethereum.org/EIPS/eip-3156
  • The source URL is not a GitHub repository. No code remote is invented.
  • Full text is not mirrored. Public availability is not a licence to copy the file onto this site.
  • Add to a reading list

01 Claim ledger

What the paper is allowed to say

Each row is a sentence already in the study. The status is the same on every row: a model claim, not a live measurement.

  1. Claim 01 · Paper model

    The defect

    A loan that must be repaid in the same transaction is either impossible, in a human process, or a primitive, in an atomic chain.

  2. Claim 02 · Paper model

    The rule

    A flash lender sends assets to a receiver and requires that the same transaction returns them, plus a fee. If it does not, the transaction reverts. There is no default in the credit sense, because there is no time.

  3. Claim 03 · Paper model

    How it is put together

    The loan and the repayment are one transaction. The lender's check is at the end. Failure reverts. It does not create a bad debt inside this interface.

  4. Claim 04 · Paper model

    Where the claim stops

    The standard does not invent the attack. It names the interface.

02 Three cuts

Observation, model, falsifier

A desk does not stop at the summary. Each claim is cut three ways, using only this study's own assumptions and checks. Nothing here is a new figure.

  1. 01 The defect

    Observation

    What the study says

    A loan that must be repaid in the same transaction is either impossible, in a human process, or a primitive, in an atomic chain.

    Model

    What has to hold

    A flash loan can still be used to manipulate a price in the same transaction.

    Falsifier

    What would retire it

    Does repayment happen before the transaction can end?

  2. 02 The rule

    Observation

    What the study says

    A flash lender sends assets to a receiver and requires that the same transaction returns them, plus a fee. If it does not, the transaction reverts. There is no default in the credit sense, because there is no time.

    Model

    What has to hold

    A flash loan can still be used to manipulate a price in the same transaction.

    Falsifier

    What would retire it

    Does repayment happen before the transaction can end?

  3. 03 How it is put together

    Observation

    What the study says

    The loan and the repayment are one transaction. The lender's check is at the end. Failure reverts. It does not create a bad debt inside this interface.

    Model

    What has to hold

    The standard does not invent the attack. It names the interface.

    Falsifier

    What would retire it

    Does repayment happen before the transaction can end?

  4. 04 Where the claim stops

    Observation

    What the study says

    The standard does not invent the attack. It names the interface.

    Model

    What has to hold

    The standard does not invent the attack. It names the interface.

    Falsifier

    What would retire it

    Does repayment happen before the transaction can end?

03 Sequence

One action, as an operating tape

  1. 01The receiver asks for an amount.
  2. 02The lender sends it and calls the receiver.
  3. 03The receiver must return the amount and the fee before the lender's function finishes.
  4. 04Does repayment happen before the transaction can end?

04 Load-bearing

The argument, and where a pitch drops it

  1. Why it is still on the desk

    The cut

    An oracle that can be moved and restored inside one transaction is compatible with this primitive. That is the risk to design against.

    Why it carries weight

    If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.

    Where it is dropped

    A flash loan can still be used to manipulate a price in the same transaction.

  2. After the text

    The cut

    Aave and others shipped flash loans before the ERC. The ERC is the common shape.

    Why it carries weight

    If this cut is skipped, the paper's name is being used without the mechanism that makes the name mean anything.

    Where it is dropped

    A flash loan can still be used to manipulate a price in the same transaction.

05 Register

What has to be true

  • Model · Not re-measured

    The standard does not invent the attack. It names the interface.

  • Model · Not re-measured

    A flash loan can still be used to manipulate a price in the same transaction.

  • Model · Not re-measured

    It is not a revolving credit line.

06 Divergence

What happened after the paper

Aave and others shipped flash loans before the ERC. The ERC is the common shape.

A later client, parameter set, or reward formula is a different object. Cite this paper for the mechanism. Cite a primary release for the network. This desk has not re-run the proof.

07 Pre-mortem

What to check before you use the idea

  4. 0 of 3 marked on this browser. A mark is a reading note, not a pass, a rating, or a recommendation.

08 Anatomy

The paper, in the order a builder needs

The problem it names

A loan that must be repaid in the same transaction is either impossible, in a human process, or a primitive, in an atomic chain.

What the design proposes

  • The loan and the repayment are one transaction.
  • The lender's check is at the end.
  • Failure reverts. It does not create a bad debt inside this interface.

How the mechanism is specified

  • The receiver asks for an amount.
  • The lender sends it and calls the receiver.
  • The receiver must return the amount and the fee before the lender's function finishes.

What this page does not treat as proven

  • The standard does not invent the attack. It names the interface.
  • A flash loan can still be used to manipulate a price in the same transaction.
  • It is not a revolving credit line.

Why the desk still reads it

An oracle that can be moved and restored inside one transaction is compatible with this primitive. That is the risk to design against.

09 Lexicon

Terms, opened into the record

Receiver
The contract that is handed the assets and must return them.
Atomic
One transaction. No later repayment exists.

10 Repository

Every linked record on this page

Underlined words open a page that already exists: a concept, a protocol profile, a failure record, or another paper. If a word is not underlined, this desk does not have a record for it.

Concepts

This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.

Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.