API

caution

Our API is still in alpha — things may change or break at any time!

If you have questions, come chat with us on Discord. We’d love to hear about what you build!

General notes

Some APIs are not associated with any particular user. Other APIs require authentication.

APIs that require authentication accept an Authorization header in one of two formats:

Authorization: Key {key}. A Manifold API key associated with a user account. Each account may have zero or one API keys. To generate an API key for your account, visit your user profile, click "edit", and click the "refresh" button next to the API key field at the bottom. You can click it again any time to invalidate your existing key and generate a new one.
Authorization: Bearer {jwt}. A signed JWT from Firebase asserting your identity. This is what our web client uses. It will probably be annoying for you to generate and we will not document it further here.

API requests that accept parameters should either have the parameters in the query string if they are GET requests, or have a body with a JSON object with one property per parameter if they are POST requests.

API responses should always either have a body with a JSON result object (if the response was a 200) or with a JSON object representing an error (if the response was a 4xx or 5xx.)

Endpoints

`GET /v0/user/[username]`

Gets a user by their username. Remember that usernames may change.

Requires no authorization.

`GET /v0/user/by-id/[id]`

Gets a user by their unique ID. Many other API endpoints return this as the userId.

Requires no authorization.

`GET /v0/markets`

Lists all markets, ordered by creation date descending.

Parameters:

limit: Optional. How many markets to return. The maximum and the default is 1000.
before: Optional. The ID of the market before which the list will start. For example, if you ask for the most recent 10 markets, and then perform a second query for 10 more markets with before=[the id of the 10th market], you will get markets 11 through 20.

Requires no authorization.

Example request

https://manifold.markets/api/v0/markets?limit=1

Example response

[
  {
    "id":"EvIhzcJXwhL0HavaszD7",
    "creatorUsername":"Austin",
    "creatorName":"Austin",
    "createdTime":1653850472294,
    "creatorAvatarUrl":"https://lh3.googleusercontent.com/a-/AOh14GiZyl1lBehuBMGyJYJhZd-N-mstaUtgE4xdI22lLw=s96-c",
    "closeTime":1653893940000,
    "question":"Will I write a new blog post today?",
    "description":"I'm supposed to, or else Beeminder charges me $90.\nTentative topic ideas:\n- \"Manifold funding, a history\"\n- \"Markets and bounties allow trades through time\"\n- \"equity vs money vs time\"\n\nClose date updated to 2022-05-29 11:59 pm",
    "tags":[
      "personal",
      "commitments"
      ],
    "url":"https://manifold.markets/Austin/will-i-write-a-new-blog-post-today",
    "pool":146.73022894879944,
    "probability":0.8958175225896258,
    "p":0.08281474972181882,
    "totalLiquidity":102.65696071594805,
    "outcomeType":"BINARY",
    "mechanism":"cpmm-1",
    "volume":241,
    "volume7Days":0,
    "volume24Hours":0,
    "isResolved":true,
    "resolution":"YES",
    "resolutionTime":1653924077078
  },
  ...

Response type: Array of LiteMarket

// Information about a market, but without bets or comments
type LiteMarket = {
  // Unique identifer for this market
  id: string

  // Attributes about the creator
  creatorUsername: string
  creatorName: string
  createdTime: number // milliseconds since epoch
  creatorAvatarUrl?: string

  // Market attributes. All times are in milliseconds since epoch
  closeTime?: number // Min of creator's chosen date, and resolutionTime
  question: string
  description: string

  // A list of tags on each market. Any user can add tags to any market.
  // This list also includes the predefined categories shown as filters on the home page.
  tags: string[]

  // Note: This url always points to https://manifold.markets, regardless of what instance the api is running on.
  // This url includes the creator's username, but this doesn't need to be correct when constructing valid URLs.
  //   i.e. https://manifold.markets/Austin/test-market is the same as https://manifold.markets/foo/test-market
  url: string

  outcomeType: string // BINARY, FREE_RESPONSE, or NUMERIC
  mechanism: string // dpm-2 or cpmm-1

  probability: number
  pool: { outcome: number } // For CPMM markets, the number of shares in the liquidity pool. For DPM markets, the amount of mana invested in each answer.
  p?: number // CPMM markets only, probability constant in y^p * n^(1-p) = k
  totalLiquidity?: number // CPMM markets only, the amount of mana deposited into the liquidity pool

  volume: number
  volume7Days: number
  volume24Hours: number

  isResolved: boolean
  resolutionTime?: number
  resolution?: string
  resolutionProbability?: number // Used for BINARY markets resolved to MKT
}

`GET /v0/market/[marketId]`

Gets information about a single market by ID. Includes comments, bets, and answers.

Requires no authorization.

Example request

https://manifold.markets/api/v0/market/3zspH9sSzMlbFQLn9GKR

Example response

{
  "id": "lEoqtnDgJzft6apSKzYK",
  "creatorUsername": "Angela",
  "creatorName": "Angela",
  "createdTime": 1655258914863,
  "creatorAvatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FAngela%2F50463444807_edfd4598d6_o.jpeg?alt=media&token=ef44e13b-2e6c-4498-b9c4-8e38bdaf1476",
  "closeTime": 1655265001448,
  "question": "What is good?",
  "description": "Resolves proportionally to the answer(s) which I find most compelling. (Obviously I’ll refrain from giving my own answers)\n\n(Please have at it with philosophy, ethics, etc etc)\n\n\nContract resolved automatically.",
  "tags": [],
  "url": "https://manifold.markets/Angela/what-is-good",
  "pool": null,
  "outcomeType": "FREE_RESPONSE",
  "mechanism": "dpm-2",
  "volume": 112,
  "volume7Days": 212,
  "volume24Hours": 0,
  "isResolved": true,
  "resolution": "MKT",
  "resolutionTime": 1655265001448,
  "answers": [
    {
      "createdTime": 1655258941573,
      "avatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FAngela%2F50463444807_edfd4598d6_o.jpeg?alt=media&token=ef44e13b-2e6c-4498-b9c4-8e38bdaf1476",
      "id": "1",
      "username": "Angela",
      "number": 1,
      "name": "Angela",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "text": "ANTE",
      "userId": "qe2QqIlOkeWsbljfeF3MsxpSJ9i2",
      "probability": 0.66749733001068
    },
    {
      "name": "Isaac King",
      "username": "IsaacKing",
      "text": "This answer",
      "userId": "y1hb6k7txdZPV5mgyxPFApZ7nQl2",
      "id": "2",
      "number": 2,
      "avatarUrl": "https://lh3.googleusercontent.com/a-/AOh14GhNVriOvxK2VUAmE-jvYZwC-XIymatzVirT0Bqb2g=s96-c",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "createdTime": 1655261198074,
      "probability": 0.008922214311142757
    },
    {
      "createdTime": 1655263226587,
      "userId": "jbgplxty4kUKIa1MmgZk22byJq03",
      "id": "3",
      "avatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FMartin%2Fgiphy.gif?alt=media&token=422ef610-553f-47e3-bf6f-c0c5cc16c70a",
      "text": "Toyota Camry",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "name": "Undox",
      "username": "Undox",
      "number": 3,
      "probability": 0.008966714133143469
    },
    {
      "number": 4,
      "name": "James Grugett",
      "userId": "5LZ4LgYuySdL1huCWe7bti02ghx2",
      "text": "Utility (Defined by your personal utility function.)",
      "createdTime": 1655264793224,
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "username": "JamesGrugett",
      "id": "4",
      "avatarUrl": "https://lh3.googleusercontent.com/a-/AOh14GjC83uMe-fEfzd6QvxiK6ZqZdlMytuHxevgMYIkpAI=s96-c",
      "probability": 0.09211463154147384
    }
  ],
  "comments": [
    {
      "id": "ZdHIyfQazHyl8nI0ENS7",
      "userId": "qe2QqIlOkeWsbljfeF3MsxpSJ9i2",
      "createdTime": 1655265807433,
      "text": "ok what\ni did not resolve this intentionally",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "userName": "Angela",
      "userAvatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FAngela%2F50463444807_edfd4598d6_o.jpeg?alt=media&token=ef44e13b-2e6c-4498-b9c4-8e38bdaf1476",
      "userUsername": "Angela"
    },
    {
      "userName": "James Grugett",
      "userUsername": "JamesGrugett",
      "id": "F7fvHGhTiFal8uTsUc9P",
      "userAvatarUrl": "https://lh3.googleusercontent.com/a-/AOh14GjC83uMe-fEfzd6QvxiK6ZqZdlMytuHxevgMYIkpAI=s96-c",
      "replyToCommentId": "ZdHIyfQazHyl8nI0ENS7",
      "text": "@Angela Sorry! There was an error that automatically resolved several markets that were created in the last few hours.",
      "createdTime": 1655266286514,
      "userId": "5LZ4LgYuySdL1huCWe7bti02ghx2",
      "contractId": "lEoqtnDgJzft6apSKzYK"
    },
    {
      "userId": "qe2QqIlOkeWsbljfeF3MsxpSJ9i2",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "id": "PIHhXy5hLHSgW8uoUD0Q",
      "userName": "Angela",
      "text": "lmk if anyone lost manna from this situation and i'll try to fix it",
      "userUsername": "Angela",
      "createdTime": 1655277581308,
      "userAvatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FAngela%2F50463444807_edfd4598d6_o.jpeg?alt=media&token=ef44e13b-2e6c-4498-b9c4-8e38bdaf1476"
    },
    {
      "userAvatarUrl": "https://firebasestorage.googleapis.com/v0/b/mantic-markets.appspot.com/o/user-images%2FAngela%2F50463444807_edfd4598d6_o.jpeg?alt=media&token=ef44e13b-2e6c-4498-b9c4-8e38bdaf1476",
      "userName": "Angela",
      "text": "from my end it looks like no one did",
      "replyToCommentId": "PIHhXy5hLHSgW8uoUD0Q",
      "createdTime": 1655287149528,
      "userUsername": "Angela",
      "id": "5slnWEQWwm6dHjDi6oiH",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "userId": "qe2QqIlOkeWsbljfeF3MsxpSJ9i2"
    }
  ],
  "bets": [
    {
      "outcome": "0",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "fees": {
        "liquidityFee": 0,
        "creatorFee": 0,
        "platformFee": 0
      },
      "isAnte": true,
      "shares": 100,
      "probAfter": 1,
      "amount": 100,
      "userId": "IPTOzEqrpkWmEzh6hwvAyY9PqFb2",
      "createdTime": 1655258914863,
      "probBefore": 0,
      "id": "2jNZqnwoEQL7WDTTAWDP"
    },
    {
      "shares": 173.20508075688772,
      "fees": {
        "platformFee": 0,
        "liquidityFee": 0,
        "creatorFee": 0
      },
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "probBefore": 0,
      "createdTime": 1655258941573,
      "loanAmount": 0,
      "userId": "qe2QqIlOkeWsbljfeF3MsxpSJ9i2",
      "amount": 100,
      "outcome": "1",
      "probAfter": 0.75,
      "id": "xuc3JoiNkE8lXPh15mUb"
    },
    {
      "userId": "y1hb6k7txdZPV5mgyxPFApZ7nQl2",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "loanAmount": 0,
      "probAfter": 0.009925496893641248,
      "id": "8TBlzPtOdO0q5BgSyRbi",
      "createdTime": 1655261198074,
      "shares": 20.024984394500787,
      "amount": 1,
      "outcome": "2",
      "probBefore": 0,
      "fees": {
        "liquidityFee": 0,
        "creatorFee": 0,
        "platformFee": 0
      }
    },
    {
      "probAfter": 0.00987648269777473,
      "outcome": "3",
      "id": "9vdwes6s9QxbYZUBhHs4",
      "createdTime": 1655263226587,
      "shares": 20.074859899884732,
      "amount": 1,
      "loanAmount": 0,
      "fees": {
        "liquidityFee": 0,
        "platformFee": 0,
        "creatorFee": 0
      },
      "userId": "jbgplxty4kUKIa1MmgZk22byJq03",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "probBefore": 0
    },
    {
      "createdTime": 1655264793224,
      "fees": {
        "creatorFee": 0,
        "liquidityFee": 0,
        "platformFee": 0
      },
      "probAfter": 0.09211463154147384,
      "amount": 10,
      "id": "BehiSGgk1wAkIWz1a8L4",
      "userId": "5LZ4LgYuySdL1huCWe7bti02ghx2",
      "contractId": "lEoqtnDgJzft6apSKzYK",
      "loanAmount": 0,
      "probBefore": 0,
      "outcome": "4",
      "shares": 64.34283176858165
    }
  ]
}

Response type: A FullMarket

// A complete market, along with bets, comments, and answers (for free response markets)
type FullMarket = LiteMarket & {
  bets: Bet[]
  comments: Comment[]
  answers?: Answer[]
}

type Bet = {
  id: string
  contractId: string

  amount: number // bet size; negative if SELL bet
  outcome: string
  shares: number // dynamic parimutuel pool weight; negative if SELL bet

  probBefore: number
  probAfter: number

  sale?: {
    amount: number // amount user makes from sale
    betId: string // id of bet being sold
  }

  isSold?: boolean // true if this BUY bet has been sold
  isAnte?: boolean

  createdTime: number
}

`GET /v0/slug/[marketSlug]`

Gets information about a single market by slug (the portion of the URL path after the username).

Requires no authorization.

Example request

https://manifold.markets/api/v0/slug/will-carrick-flynn-win-the-general

Response type: A FullMarket ; same as above.

`GET /v0/users`

Lists all users.

Requires no authorization.

Example request
```
https://manifold.markets/api/v0/users
```

Example response

[
  {
    "id":"igi2zGXsfxYPgB0DJTXVJVmwCOr2",
    "createdTime":1639011767273,
    "name":"Austin",
    "username":"Austin",
    "url":"https://manifold.markets/Austin",
    "avatarUrl":"https://lh3.googleusercontent.com/a-/AOh14GiZyl1lBehuBMGyJYJhZd-N-mstaUtgE4xdI22lLw=s96-c",
    "bio":"I build Manifold! Always happy to chat; reach out on Discord or find a time on https://calendly.com/austinchen/manifold!",
    "bannerUrl":"https://images.unsplash.com/photo-1501523460185-2aa5d2a0f981?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1531&q=80",
    "website":"https://blog.austn.io",
    "twitterHandle":"akrolsmir",
    "discordHandle":"akrolsmir#4125",
    "balance":9122.607163564959,
    "totalDeposits":10339.004780544328,
    "totalPnLCached":9376.601262721899,
    "creatorVolumeCached":76078.46984199001
  }

Response type: Array of LiteUser

// Basic information about a user
type LiteUser = {
  id: string // user's unique id
  createdTime: number

  name: string // display name, may contain spaces
  username: string // username, used in urls
  url: string // link to user's profile
  avatarUrl?: string

  bio?: string
  bannerUrl?: string
  website?: string
  twitterHandle?: string
  discordHandle?: string

  // Note: the following are here for convenience only and may be removed in the future.
  balance: number
  totalDeposits: number
  totalPnLCached: number
  creatorVolumeCached: number
}

`POST /v0/bet`

Places a new bet on behalf of the authorized user.

Parameters:

amount: Required. The amount to bet, in M$, before fees.
contractId: Required. The ID of the contract (market) to bet on.
outcome: Required. The outcome to bet on. For binary markets, this is YES or NO. For free response markets, this is the ID of the free response answer. For numeric markets, this is a string representing the target bucket, and an additional value parameter is required which is a number representing the target value. (Bet on numeric markets at your own peril.)

Example request:

$ curl https://manifold.markets/api/v0/bet -X POST -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}' \
    --data-raw '{"amount":1, \
                 "outcome":"YES", \
                 "contractId":"{...}"}'

`POST /v0/market`

Creates a new market on behalf of the authorized user.

Parameters:

outcomeType: Required. One of BINARY, FREE_RESPONSE, or NUMERIC.
question: Required. The headline question for the market.
description: Required. A long description describing the rules for the market.
closeTime: Required. The time at which the market will close, represented as milliseconds since the epoch.
tags: Optional. An array of string tags for the market.

For binary markets, you must also provide:

initialProb: An initial probability for the market, between 1 and 99.

For numeric markets, you must also provide:

min: The minimum value that the market may resolve to.
max: The maximum value that the market may resolve to.

Example request:

$ curl https://manifold.markets/api/v0/market -X POST -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}'
    --data-raw '{"outcomeType":"BINARY", \
                 "question":"Is there life on Mars?", \
                 "description":"I'm not going to type some long ass example description.", \
                 "closeTime":1700000000000, \
                 "initialProb":25}'

`POST /v0/market/[marketId]/resolve`

Resolves a market on behalf of the authorized user.

Parameters:

For binary markets:

outcome: Required. One of YES, NO, MKT, or CANCEL.
probabilityInt: Optional. The probability to use for MKT resolution.

For free response markets:

outcome: Required. One of MKT, CANCEL, or a number indicating the answer index.
resolutions: An array of { answer, pct } objects to use as the weights for resolving in favor of multiple free response options. Can only be set with MKT outcome.

For numeric markets:

outcome: Required. One of CANCEL, or a number indicating the selected numeric bucket ID.
value: The value that the market may resolves to.

Example request:

# Resolve a binary market
$ curl https://manifold.markets/api/v0/market/{marketId}/resolve -X POST \
    -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}' \
    --data-raw '{"outcome": "YES"}'

# Resolve a binary market with a specified probability
$ curl https://manifold.markets/api/v0/market/{marketId}/resolve -X POST \
    -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}' \
    --data-raw '{"outcome": "MKT", \
                 "probabilityInt": 75}'

# Resolve a free response market with a single answer chosen
$ curl https://manifold.markets/api/v0/market/{marketId}/resolve -X POST \
    -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}' \
    --data-raw '{"outcome": 2}'

# Resolve a free response market with multiple answers chosen
$ curl https://manifold.markets/api/v0/market/{marketId}/resolve -X POST \
    -H 'Content-Type: application/json' \
    -H 'Authorization: Key {...}' \
    --data-raw '{"outcome": "MKT", \
                 "resolutions": [ \
                   {"answer": 0, "pct": 50}, \
                   {"answer": 2, "pct": 50} \
                 ]}'

`GET /v0/bets`

Gets a list of bets, ordered by creation date descending.

Parameters:

username: Optional. If set, the response will include only bets created by this user.
market: Optional. The slug of a market. If set, the response will only include bets on this market.
limit: Optional. How many bets to return. The maximum and the default is 1000.
before: Optional. The ID of the bet before which the list will start. For example, if you ask for the most recent 10 bets, and then perform a second query for 10 more bets with before=[the id of the 10th bet], you will get bets 11 through 20.

Requires no authorization.

Example request

https://manifold.markets/api/v0/bets?username=ManifoldMarkets&market=will-california-abolish-daylight-sa

Response type: A Bet[].

Example response

[
  {
    "probAfter": 0.44418877319153904,
    "shares": -645.8346334931828,
    "outcome": "YES",
    "contractId": "tgB1XmvFXZNhjr3xMNLp",
    "sale": {
      "betId": "RcOtarI3d1DUUTjiE0rx",
      "amount": 474.9999999999998
    },
    "createdTime": 1644602886293,
    "userId": "94YYTk1AFWfbWMpfYcvnnwI1veP2",
    "probBefore": 0.7229189477449224,
    "id": "x9eNmCaqQeXW8AgJ8Zmp",
    "amount": -499.9999999999998
  },
  {
    "probAfter": 0.9901970375647697,
    "contractId": "zdeaYVAfHlo9jKzWh57J",
    "outcome": "YES",
    "amount": 1,
    "id": "8PqxKYwXCcLYoXy2m2Nm",
    "shares": 1.0049875638533763,
    "userId": "94YYTk1AFWfbWMpfYcvnnwI1veP2",
    "probBefore": 0.9900000000000001,
    "createdTime": 1644705818872
  }
]

Changelog

2022-07-15: Add user by username and user by ID APIs
2022-06-08: Add paging to markets endpoint
2022-06-05: Add new authorized write endpoints
2022-02-28: Add resolutionTime to markets, change closeTime definition
2022-02-19: Removed user IDs from bets
2022-02-17: Released our v0 API, with /markets, /market/[marketId], and /slug/[slugId]

API

caution

General notes​

Endpoints​

GET /v0/user/[username]​

GET /v0/user/by-id/[id]​

GET /v0/markets​

GET /v0/market/[marketId]​

GET /v0/slug/[marketSlug]​

GET /v0/users​

POST /v0/bet​

POST /v0/market​

POST /v0/market/[marketId]/resolve​

GET /v0/bets​

Changelog​

General notes

Endpoints

`GET /v0/user/[username]`

`GET /v0/user/by-id/[id]`

`GET /v0/markets`

`GET /v0/market/[marketId]`

`GET /v0/slug/[marketSlug]`

`GET /v0/users`

`POST /v0/bet`

`POST /v0/market`

`POST /v0/market/[marketId]/resolve`

`GET /v0/bets`

Changelog