From 88972faf087319edb90bbe153de2db3f9ff46a12 Mon Sep 17 00:00:00 2001 From: jochen Date: Wed, 4 Nov 2026 12:26:44 +0100 Subject: [PATCH] SD-M2a: a publish-part chunk is at most 760 KiB, so its message stays under the bus's 1 MiB with its fields Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig --- go/parts/registry/contract.go | 2 +- go/seats/seats.go | 16 ++++++++-------- parts/registry.json | 4 ++-- ts/src/parts/registry.ts | 2 +- ts/src/seats.ts | 16 ++++++++-------- 5 files changed, 20 insertions(+), 20 deletions(-) diff --git a/go/parts/registry/contract.go b/go/parts/registry/contract.go index 81d4e3b..e155910 100644 --- a/go/parts/registry/contract.go +++ b/go/parts/registry/contract.go @@ -102,7 +102,7 @@ type PublishAnswer struct { // PublishPartInput is what publish-part takes. type PublishPartInput struct { - // the chunk's bytes, base64 (at most 768 KiB before encoding) + // the chunk's bytes, base64 (at most 760 KiB before encoding) Data string `json:"data"` // this chunk is the part's last Last bool `json:"last"` diff --git a/go/seats/seats.go b/go/seats/seats.go index 5e4e996..daa7022 100644 --- a/go/seats/seats.go +++ b/go/seats/seats.go @@ -386,8 +386,8 @@ func List() []Seat { {Name: "publish", Description: "Open a transfer, naming the artifact and the digest of every part; answers the digests the holder lacks, which the caller then sends by publish-part. A transfer already open answers the parts held, so a cut transfer goes on from there. With no parts and a version, the held digest is published under that version and nothing is stored (the trunk's claim).", Input: map[string]any{"properties": map[string]any{"commit": map[string]any{"description": "the source commit it was built from", "type": "string"}, "digest": map[string]any{"description": "its digest, sha256: (a Go package's h1: hash beside it in the version's record)", "type": "string"}, "fingerprint": map[string]any{"description": "the build's fingerprint", "type": "string"}, "kind": map[string]any{"description": "what it is", "enum": []string{"package", "image", "bundle", "archive", "upstream"}, "type": "string"}, "name": map[string]any{"description": "the package's, image's, bundle's or archive's name", "type": "string"}, "parts": map[string]any{"description": "every part's digest and size; none when the digest is already held", "items": map[string]any{"description": "one part of a transfer", "properties": map[string]any{"digest": map[string]any{"description": "the part's digest, sha256:: an image's layer or config, a package's file, a bundle's blob", "type": "string"}, "size": map[string]any{"description": "its size in bytes", "type": "integer"}}, "required": []string{"digest", "size"}, "type": "object"}, "type": "array"}, "tag": map[string]any{"description": "the tag it carries, for a tagged version", "type": "string"}, "transfer": map[string]any{"description": "the transfer's name, the caller's own; the same name opens the same transfer again", "type": "string"}, "version": map[string]any{"description": "the version the builder gave it (design 51 *The versions*); empty for a bundle or archive published by its digest alone", "type": "string"}}, "required": []string{"transfer", "name", "kind", "digest"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"held": map[string]any{"description": "the digest is held already: nothing to send; the outcome follows as an event", "type": "boolean"}, "lacks": map[string]any{"description": "the digests of the parts the holder lacks, to send by publish-part", "items": map[string]any{"type": "string"}, "type": "array"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer"}, "type": "object"}}, - {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", - Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, + {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", + Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"complete": map[string]any{"description": "the part is whole and its bytes match its digest", "type": "boolean"}, "part": map[string]any{"description": "the part", "type": "string"}, "received": map[string]any{"description": "the chunks of the part held so far", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part"}, "type": "object"}}, {Name: "versions", Description: "The versions the seat holds of one name, newest first: each one's version, tag, digest, kind and when it was published.", Input: map[string]any{"properties": map[string]any{"kind": map[string]any{"description": "narrowed to one kind (optional)", "type": "string"}, "name": map[string]any{"description": "the name", "type": "string"}}, "required": []string{"name"}, "type": "object"}, @@ -401,8 +401,8 @@ func List() []Seat { {Name: "publish", Description: "Open a transfer, naming the artifact and the digest of every part; answers the digests the holder lacks, which the caller then sends by publish-part. A transfer already open answers the parts held, so a cut transfer goes on from there. With no parts and a version, the held digest is published under that version and nothing is stored (the trunk's claim).", Input: map[string]any{"properties": map[string]any{"commit": map[string]any{"description": "the source commit it was built from", "type": "string"}, "digest": map[string]any{"description": "its digest, sha256: (a Go package's h1: hash beside it in the version's record)", "type": "string"}, "fingerprint": map[string]any{"description": "the build's fingerprint", "type": "string"}, "kind": map[string]any{"description": "what it is", "enum": []string{"package", "image", "bundle", "archive", "upstream"}, "type": "string"}, "name": map[string]any{"description": "the package's, image's, bundle's or archive's name", "type": "string"}, "parts": map[string]any{"description": "every part's digest and size; none when the digest is already held", "items": map[string]any{"description": "one part of a transfer", "properties": map[string]any{"digest": map[string]any{"description": "the part's digest, sha256:: an image's layer or config, a package's file, a bundle's blob", "type": "string"}, "size": map[string]any{"description": "its size in bytes", "type": "integer"}}, "required": []string{"digest", "size"}, "type": "object"}, "type": "array"}, "tag": map[string]any{"description": "the tag it carries, for a tagged version", "type": "string"}, "transfer": map[string]any{"description": "the transfer's name, the caller's own; the same name opens the same transfer again", "type": "string"}, "version": map[string]any{"description": "the version the builder gave it (design 51 *The versions*); empty for a bundle or archive published by its digest alone", "type": "string"}}, "required": []string{"transfer", "name", "kind", "digest"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"held": map[string]any{"description": "the digest is held already: nothing to send; the outcome follows as an event", "type": "boolean"}, "lacks": map[string]any{"description": "the digests of the parts the holder lacks, to send by publish-part", "items": map[string]any{"type": "string"}, "type": "array"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer"}, "type": "object"}}, - {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", - Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, + {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", + Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"complete": map[string]any{"description": "the part is whole and its bytes match its digest", "type": "boolean"}, "part": map[string]any{"description": "the part", "type": "string"}, "received": map[string]any{"description": "the chunks of the part held so far", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part"}, "type": "object"}}, {Name: "versions", Description: "The versions the seat holds of one name, newest first: each one's version, tag, digest, kind and when it was published.", Input: map[string]any{"properties": map[string]any{"kind": map[string]any{"description": "narrowed to one kind (optional)", "type": "string"}, "name": map[string]any{"description": "the name", "type": "string"}}, "required": []string{"name"}, "type": "object"}, @@ -416,8 +416,8 @@ func List() []Seat { {Name: "publish", Description: "Open a transfer, naming the artifact and the digest of every part; answers the digests the holder lacks, which the caller then sends by publish-part. A transfer already open answers the parts held, so a cut transfer goes on from there. With no parts and a version, the held digest is published under that version and nothing is stored (the trunk's claim).", Input: map[string]any{"properties": map[string]any{"commit": map[string]any{"description": "the source commit it was built from", "type": "string"}, "digest": map[string]any{"description": "its digest, sha256: (a Go package's h1: hash beside it in the version's record)", "type": "string"}, "fingerprint": map[string]any{"description": "the build's fingerprint", "type": "string"}, "kind": map[string]any{"description": "what it is", "enum": []string{"package", "image", "bundle", "archive", "upstream"}, "type": "string"}, "name": map[string]any{"description": "the package's, image's, bundle's or archive's name", "type": "string"}, "parts": map[string]any{"description": "every part's digest and size; none when the digest is already held", "items": map[string]any{"description": "one part of a transfer", "properties": map[string]any{"digest": map[string]any{"description": "the part's digest, sha256:: an image's layer or config, a package's file, a bundle's blob", "type": "string"}, "size": map[string]any{"description": "its size in bytes", "type": "integer"}}, "required": []string{"digest", "size"}, "type": "object"}, "type": "array"}, "tag": map[string]any{"description": "the tag it carries, for a tagged version", "type": "string"}, "transfer": map[string]any{"description": "the transfer's name, the caller's own; the same name opens the same transfer again", "type": "string"}, "version": map[string]any{"description": "the version the builder gave it (design 51 *The versions*); empty for a bundle or archive published by its digest alone", "type": "string"}}, "required": []string{"transfer", "name", "kind", "digest"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"held": map[string]any{"description": "the digest is held already: nothing to send; the outcome follows as an event", "type": "boolean"}, "lacks": map[string]any{"description": "the digests of the parts the holder lacks, to send by publish-part", "items": map[string]any{"type": "string"}, "type": "array"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer"}, "type": "object"}}, - {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", - Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, + {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", + Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"complete": map[string]any{"description": "the part is whole and its bytes match its digest", "type": "boolean"}, "part": map[string]any{"description": "the part", "type": "string"}, "received": map[string]any{"description": "the chunks of the part held so far", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part"}, "type": "object"}}, {Name: "versions", Description: "The versions the seat holds of one name, newest first: each one's version, tag, digest, kind and when it was published.", Input: map[string]any{"properties": map[string]any{"kind": map[string]any{"description": "narrowed to one kind (optional)", "type": "string"}, "name": map[string]any{"description": "the name", "type": "string"}}, "required": []string{"name"}, "type": "object"}, @@ -443,8 +443,8 @@ func List() []Seat { {Name: "publish", Description: "Open a transfer, naming the artifact and the digest of every part; answers the digests the holder lacks, which the caller then sends by publish-part. A transfer already open answers the parts held, so a cut transfer goes on from there. With no parts and a version, the held digest is published under that version and nothing is stored (the trunk's claim).", Input: map[string]any{"properties": map[string]any{"commit": map[string]any{"description": "the source commit it was built from", "type": "string"}, "digest": map[string]any{"description": "its digest, sha256: (a Go package's h1: hash beside it in the version's record)", "type": "string"}, "fingerprint": map[string]any{"description": "the build's fingerprint", "type": "string"}, "kind": map[string]any{"description": "what it is", "enum": []string{"package", "image", "bundle", "archive", "upstream"}, "type": "string"}, "name": map[string]any{"description": "the package's, image's, bundle's or archive's name", "type": "string"}, "parts": map[string]any{"description": "every part's digest and size; none when the digest is already held", "items": map[string]any{"description": "one part of a transfer", "properties": map[string]any{"digest": map[string]any{"description": "the part's digest, sha256:: an image's layer or config, a package's file, a bundle's blob", "type": "string"}, "size": map[string]any{"description": "its size in bytes", "type": "integer"}}, "required": []string{"digest", "size"}, "type": "object"}, "type": "array"}, "tag": map[string]any{"description": "the tag it carries, for a tagged version", "type": "string"}, "transfer": map[string]any{"description": "the transfer's name, the caller's own; the same name opens the same transfer again", "type": "string"}, "version": map[string]any{"description": "the version the builder gave it (design 51 *The versions*); empty for a bundle or archive published by its digest alone", "type": "string"}}, "required": []string{"transfer", "name", "kind", "digest"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"held": map[string]any{"description": "the digest is held already: nothing to send; the outcome follows as an event", "type": "boolean"}, "lacks": map[string]any{"description": "the digests of the parts the holder lacks, to send by publish-part", "items": map[string]any{"type": "string"}, "type": "array"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer"}, "type": "object"}}, - {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", - Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, + {Name: "publish-part", Description: "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", + Input: map[string]any{"properties": map[string]any{"data": map[string]any{"description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string"}, "last": map[string]any{"description": "this chunk is the part's last", "type": "boolean"}, "part": map[string]any{"description": "the part's digest", "type": "string"}, "sequence": map[string]any{"description": "the chunk's place in its part, from 0", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part", "sequence", "last", "data"}, "type": "object"}, Output: map[string]any{"properties": map[string]any{"complete": map[string]any{"description": "the part is whole and its bytes match its digest", "type": "boolean"}, "part": map[string]any{"description": "the part", "type": "string"}, "received": map[string]any{"description": "the chunks of the part held so far", "type": "integer"}, "transfer": map[string]any{"description": "the transfer", "type": "string"}}, "required": []string{"transfer", "part"}, "type": "object"}}, {Name: "versions", Description: "The versions the seat holds of one name, newest first: each one's version, tag, digest, kind and when it was published.", Input: map[string]any{"properties": map[string]any{"kind": map[string]any{"description": "narrowed to one kind (optional)", "type": "string"}, "name": map[string]any{"description": "the name", "type": "string"}}, "required": []string{"name"}, "type": "object"}, diff --git a/parts/registry.json b/parts/registry.json index af29f85..ccfe514 100644 --- a/parts/registry.json +++ b/parts/registry.json @@ -90,7 +90,7 @@ }, { "name": "publish-part", - "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", + "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", "callers": "the build modules, and only the proved caller that opened the transfer", "input": { "type": "object", @@ -113,7 +113,7 @@ }, "data": { "type": "string", - "description": "the chunk's bytes, base64 (at most 768 KiB before encoding)" + "description": "the chunk's bytes, base64 (at most 760 KiB before encoding)" } }, "required": [ diff --git a/ts/src/parts/registry.ts b/ts/src/parts/registry.ts index e13b4d2..71cc661 100644 --- a/ts/src/parts/registry.ts +++ b/ts/src/parts/registry.ts @@ -101,7 +101,7 @@ export interface PublishAnswer { /** is what publish-part takes. */ export interface PublishPartInput { - /** the chunk's bytes, base64 (at most 768 KiB before encoding) */ + /** the chunk's bytes, base64 (at most 760 KiB before encoding) */ "data": string; /** this chunk is the part's last */ "last": boolean; diff --git a/ts/src/seats.ts b/ts/src/seats.ts index 3cbdb10..c44b230 100644 --- a/ts/src/seats.ts +++ b/ts/src/seats.ts @@ -2980,11 +2980,11 @@ export const list: readonly Seat[] = [ } }, { - "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", + "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", "input": { "properties": { "data": { - "description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", + "description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string" }, "last": { @@ -3332,11 +3332,11 @@ export const list: readonly Seat[] = [ } }, { - "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", + "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", "input": { "properties": { "data": { - "description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", + "description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string" }, "last": { @@ -3686,11 +3686,11 @@ export const list: readonly Seat[] = [ } }, { - "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", + "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", "input": { "properties": { "data": { - "description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", + "description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string" }, "last": { @@ -4213,11 +4213,11 @@ export const list: readonly Seat[] = [ } }, { - "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 768 KiB of data, base64.", + "description": "Send one chunk of one part of an open transfer; the last chunk of the last part ends the transfer, and the holder hashes what it received, asks builder_versions, stores it and says published or refused. A chunk's message stays under the bus's largest message (1 MiB), so at most 760 KiB of data, base64.", "input": { "properties": { "data": { - "description": "the chunk's bytes, base64 (at most 768 KiB before encoding)", + "description": "the chunk's bytes, base64 (at most 760 KiB before encoding)", "type": "string" }, "last": {