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Schema Negotiation

Paul Frazee // Bluesky

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TCP

HTTP

JSON

???

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TCP

HTTP

JSON

???

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FLEXIBLE

CORRECT

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INTENT

RESULT

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INTENT

RESULT

VIOLATION

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{

"type": "tweet",

"media": ["sock.jpg"]

}

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{

"type": "tweet",

"media": ["sock.jpg"],

"status": "picture-of-the-day"

}

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{

"type": "tweet",

"media": ["sock.jpg"],

"status": "picture-of-the-day"

}

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{

"type": "tweet",

"media": ["sock.jpg"],

"status": "picture-of-the-day"

}

INTENT

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{

"type": "tweet",

"media": ["sock.jpg"],

"category": "sock-pictures"

}

INTENT

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{

"type": "tweet",

"media": ["sock.jpg"],

"contentWarning": "dirty-socks"

}

INTENT

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{

"type": "tweet",

"media": ["sock.jpg"],

"to": "bob@mail.com",

"cc": "sock-lovers@mail.com"

}

INTENT

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{

"type": "tweet",

"media": ["sock.jpg"],

"to": "bob@mail.com",

"cc": "sock-lovers@mail.com"

}

INTENT

CONTRACT

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1

Schema is a contract

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interface Post {

text: string,

media: string[]

}

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interface Post {

text: string,

media: string[]

}

V1

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media: MediaEmbed[]

}

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media: MediaEmbed[]

}

V2

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media: MediaEmbed[]

}

V2

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media: MediaEmbed[]

}

V2

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media:

(string|MediaEmbed)[]

}

V2

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media:

(string|MediaEmbed)[]

}

V2

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interface Post {

text: string,

media: string[]

}

V1

interface Post {

text: string,

media: string[],

mediaExt?: MediaEmbed[]

}

V2

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1

Schema is a contract

2

Minor revisions only

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SCHEMA NEGOTIATION

SUPPORTED SCHEMAS

REQUIRED SCHEMAS

Consumer

Provider

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I understand

POST

POSTv2

COMMENT

"

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

POSTv2

StatusUpdates

Base

Type

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

POSTv2

StatusUpdate

Extension Type

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

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I understand

POST

POSTv2

COMMENT

StatusUpdate

"

{..}

.json

StatusUpdate

POSTv2

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I understand

POST

POSTv2

COMMENT

StatusUpdate

"

{..}

.json

StatusUpdate

POSTv2

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

Fallback: IGNORE

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

Fallback: WARN

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I understand

POST

POSTv2

COMMENT

"

{..}

.json

StatusUpdate

POSTv2

Fallback: ERROR

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SCHEMA NEGOTIATION

SUPPORTED SCHEMAS

REQUIRED SCHEMAS

Consumer

Provider

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v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

DECLARE SUPPORT

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VALIDATE RECORD

res = v.validate({

type: 'Post',

text: 'Hello, world!'

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? YES

res = v.validate({

type: 'Post',

text: 'Hello, world!'

})

res.supported == true

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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VALID? YES

res = v.validate({

type: 'Post',

text: 'Hello, world!'

})

res.supported == true

res.valid == true

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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VALID? NO

res = v.validate({

type: 'Post',

text: 12345

})

res.supported == true

res.valid == false

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? NO

res = v.validate({

type: 'OtherPost',

text: 'Hello World'

})

res.supported == false

res.valid == undefined

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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EXTENSION

res = v.validate({

type: 'Post',

text: 'Hello World',

ext: {

type: 'StatusUpdate',

value: 'picture-of-the-day'

}

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? YES

res = v.validate({

type: 'Post',

text: 'Hello World',

ext: {

type: 'StatusUpdate',

value: 'picture-of-the-day'

}

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? NO BUT IGNORE

res = v.validate({

type: 'Post',

text: 'Hello World',

ext: {

type: 'Poll',

question: 'A or B?'

}

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? NO, WARN

res = v.validate({

type: 'Post',

text: 'Hello World',

ext: {

type: 'Poll',

question: 'A or B?',

fallback: 'This post contains a poll…'

}

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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SUPPORTED? NO, FAIL

res = v.validate({

type: 'Post',

text: 'Hello World',

ext: {

type: 'Poll',

question: 'A or B?',

required: true

}

})

v = createValidator({

base: ['Post', 'Post.v2', 'Comment'],

ext: ['StatusUpdate']

})

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1

Schema is a contract

2

Minor revisions only

3

Extend by negotiation

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(WIP)

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Thanks!

Paul Frazee // Bluesky