LibraryStorage and networks2022Design paperCorpus record
Ancestor Package Relay
BIP 331. Gloria Zhao.
BIP 331, Ancestor Package Relay. Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
Status in the source: Draft. A reading of the public specification, not a copy of it and not a certification.
Ancestor Package Relay is worth reading for the rule it actually adds: Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
- Evidence
- Primary paper
- Re-measured
- No
- Assumptions
- 3
- Records linked
- 3
Code
Source, repository, and what is actually hosted
- BIP 331https://bips.dev/331
- 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.
Claim 01 · Paper model
The rule
Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
Claim 02 · Paper model
What was already failing
A node that cannot fetch, filter, or relay the data it is supposed to validate is not a peer of the network the paper describes.
Claim 03 · Paper model
What the number does not mean
The source marks this draft. It is not a live consensus rule just because it has a number.
Claim 04 · Paper model
What a builder should be able to point at
An implementation either constrains no_package_info or it is a different design.
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.
01 The rule
Observation
What the study says
Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
Model
What has to hold
The object that has to change is no_package_info. A neighbouring document with a similar name is not this one.
Falsifier
What would retire it
Which message does Ancestor Package Relay add, and which old peer must still be answered?
02 What was already failing
Observation
What the study says
A node that cannot fetch, filter, or relay the data it is supposed to validate is not a peer of the network the paper describes.
Model
What has to hold
The object that has to change is no_package_info. A neighbouring document with a similar name is not this one.
Falsifier
What would retire it
Which message does Ancestor Package Relay add, and which old peer must still be answered?
03 What the number does not mean
Observation
What the study says
The source marks this draft. It is not a live consensus rule just because it has a number.
Model
What has to hold
You are implementing BIP 331 at the status the text itself states: Draft.
Falsifier
What would retire it
Which names are normative: no_package_info?
04 What a builder should be able to point at
Observation
What the study says
An implementation either constrains no_package_info or it is a different design.
Model
What has to hold
The object that has to change is no_package_info. A neighbouring document with a similar name is not this one.
Falsifier
What would retire it
Which message does Ancestor Package Relay add, and which old peer must still be answered?
03 Sequence
One action, as an operating tape
- 01Open BIP 331 and read the status line before the examples.
- 02Write down the rule in one sentence. A fair version of that sentence is: Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
- 03Name the object that changes: no_package_info.
- 04Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.
04 Load-bearing
The argument, and where a pitch drops it
What the text is allowed to settle
The cut
Bitcoin Improvement Proposal 331 can settle the shape of Ancestor Package Relay. It cannot settle whether a later client, a later fork, or a later wallet still does this.
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 peer protocol is not a consensus rule. A peer can disconnect. A block is still valid or not on its own.
What this page will not pretend
The cut
There is no benchmark, no adoption number, and no claim that the mechanism is safe outside the assumptions written in the source.
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
The source marks this draft. It is not a live consensus rule just because it has a number.
05 Register
What has to be true
Model · Not re-measured
You are implementing BIP 331 at the status the text itself states: Draft.
Model · Not re-measured
The object that has to change is no_package_info. A neighbouring document with a similar name is not this one.
Network · Not re-measured
Measurements of delay in one year do not travel with the specification.
06 Divergence
What happened after the paper
The source marks this draft. It is not a live consensus rule just because it has a number. Later documents can narrow, replace, or ignore this one. Cite the number you mean.
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
- 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 node that cannot fetch, filter, or relay the data it is supposed to validate is not a peer of the network the paper describes.
What the design proposes
- Peer-to-peer protocol messages enabling nodes to request and relay the unconfirmed ancestor package of a given transaction, and to request and relay transactions in batches.
- Ancestor Package Relay includes two parts: a package information round and a transaction data download round.
- The package information round is used to help a receiver learn what transactions are in a package and decide whether they want to download them.
How the mechanism is specified
- Taken from the specification, the next constraint is: Ancestor Package Relay includes two parts: a package information round and a transaction data download round.
- Locate no_package_info in BIP 331 and apply it to one transaction or call.
- Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.
What this page does not treat as proven
Why the desk still reads it
Use BIP 331 when a pitch says 'Ancestor Package Relay' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.
09 Lexicon
Terms, opened into the record
- BIP 331
- The public text titled Ancestor Package Relay.
- Draft
- The document's own label for how finished the text is. It is not a market fact.
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.
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.