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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/me​

Returns the authenticated user.

GET /v0/groups​

Gets all groups, in no particular order.

Parameters:

  • availableToUserId: Optional. if specified, only groups that the user can join and groups they've already joined will be returned.

Requires no authorization.

GET /v0/group/[slug]​

Gets a group by its slug.

Requires no authorization. Note: group is singular in the URL.

GET /v0/group/by-id/[id]​

Gets a group by its unique ID.

Requires no authorization. Note: group is singular in the URL.

GET /v0/group/by-id/[id]/markets​

Gets a group's markets by its unique ID.

Requires no authorization. Note: group is singular in the URL.

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?",
    "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,
    "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

    // 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, MULTIPLE_CHOICE, NUMERIC, or PSEUDO_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
    min?: number // PSEUDO_NUMERIC markets only, the minimum resolvable value
    max?: number // PSEUDO_NUMERIC markets only, the maximum resolvable value
    isLogScale?: bool // PSEUDO_NUMERIC markets only, if true `number = (max - min + 1)^probability + minstart - 1`, otherwise `number = min + (max - min) * probability`

    volume: number
    volume24Hours: number

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

    lastUpdatedTime?: number
    }

GET /v0/market/[marketId]​

Gets information about a single market by ID. Includes answers, but not bets and comments. Use /bets or /comments with a market ID to retrieve bets or comments.

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,
    "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
    }
    ]
    }

  • Response type: A FullMarket

    // A complete market, along with answers (for free response markets)
    type FullMarket = LiteMarket & {
    answers?: Answer[] // dpm-2 markets only
    description: JSONContent // Rich text content. See https://tiptap.dev/guide/output#option-1-json
    textDescription: string // string description without formatting, images, or embeds
    }

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, ordered by creation date descending.

Parameters:

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

Requires no authorization.

  • Example request

    https://manifold.markets/api/v0/users?limit=1
  • 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,
    }
  • 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
    }

POST /v0/bet​

Places a new bet on behalf of the authorized user.

Parameters:

  • amount: Required. The amount to bet, in mana, 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.)
  • limitProb: Optional. A number between 0.001 and 0.999 inclusive representing the limit probability for your bet (i.e. 0.1% to 99.9% — multiply by 100 for the probability percentage). The bet will execute immediately in the direction of outcome, but not beyond this specified limit. If not all the bet is filled, the bet will remain as an open offer that can later be matched against an opposite direction bet.
    • For example, if the current market probability is 50%:
      • A M$10 bet on YES with limitProb=0.4 would not be filled until the market probability moves down to 40% and someone bets M$15 of NO to match your bet odds.
      • A M$100 bet on YES with limitProb=0.6 would fill partially or completely depending on current unfilled limit bets and the AMM's liquidity. Any remaining portion of the bet not filled would remain to be matched against in the future.
    • An unfilled limit order bet can be cancelled using the cancel API.

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/bet/cancel/[id]​

Cancel the limit order of a bet with the specified id. If the bet was unfilled, it will be cancelled so that no other bets will match with it. This is action irreversable.

POST /v0/market​

Creates a new market on behalf of the authorized user.

Note: this costs mana. If you have insufficient mana, this call will return an error. The cost to create each type of market is:

Market TypeCreation Cost
BINARYM$50
PSEUDO_NUMERICM$250
FREE_RESPONSEM$100
MULTIPLE_CHOICEM$100

Parameters:

  • outcomeType: Required. One of BINARY, FREE_RESPONSE, MULTIPLE_CHOICE, or PSEUDO_NUMERIC.
  • question: Required. The headline question for the market.
  • description: Optional. A long description describing the rules for the market.
    • Note: string descriptions do not turn into links, mentions, formatted text. You may instead use descriptionMarkdown or descriptionHtml for rich text formatting.
  • closeTime: Optional. The time at which the market will close, represented as milliseconds since the epoch. Defaults to 7 days from now.
  • visibility: Optional. One of public (default) or unlisted. Controls whether the market is shown on the homepage.
  • groupId: Optional. A group to create this market under.

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.
  • isLogScale: If true, your numeric market will increase exponentially from min to max.
  • initialValue: An initial value for the market, between min and max, exclusive.

For multiple choice markets, you must also provide:

  • answers: An array of strings, each of which will be a valid answer for the market.

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]/add-liquidity​

Adds a specified amount of liquidity into the market.

  • amount: Required. The amount of liquidity to add, in M$.

POST /v0/market/[marketId]/close​

Closes a market on behalf of the authorized user.

  • closeTime: Optional. Milliseconds since the epoch to close the market at. If not provided, the market will be closed immediately. Cannot provide close time in past.

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 or multiple choice 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. Note that the total weights must add to 100.

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.
  • probabilityInt: Required if value is present. Should be equal to
    • If log scale: log10(value - min + 1) / log10(max - min + 1)
    • Otherwise: (value - min) / (max - min)

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} \
]}'

POST /v0/market/[marketId]/sell​

Sells some quantity of shares in a binary market on behalf of the authorized user.

Parameters:

  • outcome: Optional. One of YES, or NO. If you leave it off, and you only own one kind of shares, you will sell that kind of shares.
  • shares: Optional. The amount of shares to sell of the outcome given above. If not provided, all the shares you own will be sold.

Example request:

$ curl https://manifold.markets/api/v0/market/{marketId}/sell -X POST \
-H 'Content-Type: application/json' \
-H 'Authorization: Key {...}' \
--data-raw '{"outcome": "YES", "shares": 10}'

POST /v0/comment​

Creates a comment in the specified market. Only supports top-level comments for now.

Parameters:

  • contractId: Required. The ID of the market to comment on.
  • content: The comment to post, formatted as TipTap json, OR
  • html: The comment to post, formatted as an HTML string, OR
  • markdown: The comment to post, formatted as a markdown string.

GET /v0/comments​

Gets a list of comments for a contract, ordered by creation date descending.

Parameters:

  • contractId: Optional. Which contract to read comments for. Either an ID or slug must be specified.
  • contractSlug: Optional.

Requires no authorization.

GET /v0/bets​

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

Parameters:

  • userId: Optional. If set, the response will include only bets created by this user.
  • username: Optional. If set, the response will include only bets created by this user.
  • contractId: Optional. If set, the response will only include bets on this contract.
  • contractSlug: Optional. If set, the response will only include bets on this contract.
  • 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&contractSlug=will-i-be-able-to-place-a-limit-ord
  • Response type: A Bet[].

  • Example response

    [
    // Limit bet, partially filled.
    {
    "isFilled": false,
    "amount": 15.596681605353808,
    "userId": "IPTOzEqrpkWmEzh6hwvAyY9PqFb2",
    "contractId": "Tz5dA01GkK5QKiQfZeDL",
    "probBefore": 0.5730753474948571,
    "isCancelled": false,
    "outcome": "YES",
    "fees": { "creatorFee": 0, "liquidityFee": 0, "platformFee": 0 },
    "shares": 31.193363210707616,
    "limitProb": 0.5,
    "id": "yXB8lVbs86TKkhWA1FVi",
    "loanAmount": 0,
    "orderAmount": 100,
    "probAfter": 0.5730753474948571,
    "createdTime": 1659482775970,
    "fills": [
    {
    "timestamp": 1659483249648,
    "matchedBetId": "MfrMd5HTiGASDXzqibr7",
    "amount": 15.596681605353808,
    "shares": 31.193363210707616
    }
    ]
    },
    // Normal bet (no limitProb specified).
    {
    "shares": 17.350459904608414,
    "probBefore": 0.5304358279113885,
    "isFilled": true,
    "probAfter": 0.5730753474948571,
    "userId": "IPTOzEqrpkWmEzh6hwvAyY9PqFb2",
    "amount": 10,
    "contractId": "Tz5dA01GkK5QKiQfZeDL",
    "id": "1LPJHNz5oAX4K6YtJlP1",
    "fees": {
    "platformFee": 0,
    "liquidityFee": 0,
    "creatorFee": 0.4251333951457593
    },
    "isCancelled": false,
    "loanAmount": 0,
    "orderAmount": 10,
    "fills": [
    {
    "amount": 10,
    "matchedBetId": null,
    "shares": 17.350459904608414,
    "timestamp": 1659482757271
    }
    ],
    "createdTime": 1659482757271,
    "outcome": "YES"
    }
    ]

Changelog​

  • 2022-11-22: Update /market GET to remove bets and comments
  • 2022-10-17: Update /market POST to allow visibility and groupId; mark closeTime as optional; remove tags
  • 2022-09-24: Expand market POST docs to include new market types (PSEUDO_NUMERIC, MULTIPLE_CHOICE)
  • 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]