Refactor contract typing to be more concise and more correct (#355)

* Refactor contract types slightly * Refactor contract types greatly * Kill dead binary DPM contract creation code * Use BinaryContract, DPMContract, etc. type aliases
2022-05-31 19:42:35 -07:00 · 2022-05-31 19:42:35 -07:00 · 7c4ec2a8e3
commit 7c4ec2a8e3
parent 30adb5e1f8
45 changed files with 245 additions and 436 deletions
--- a/common/add-liquidity.ts
+++ b/common/add-liquidity.ts
@ -1,12 +1,12 @@
 import { addCpmmLiquidity, getCpmmLiquidity } from './calculate-cpmm'
-import { Binary, CPMM, FullContract } from './contract'
+import { CPMMContract } from './contract'
 import { LiquidityProvision } from './liquidity-provision'
 import { User } from './user'

 export const getNewLiquidityProvision = (
  user: User,
  amount: number,
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  newLiquidityProvisionId: string
 ) => {
  const { pool, p, totalLiquidity } = contract
--- a/common/antes.ts
+++ b/common/antes.ts
@ -2,12 +2,10 @@ import { range } from 'lodash'
 import { Bet, NumericBet } from './bet'
 import { getDpmProbability, getValueFromBucket } from './calculate-dpm'
 import {
-  Binary,
-  CPMM,
-  DPM,
-  FreeResponse,
-  FullContract,
-  Numeric,
+  CPMMBinaryContract,
+  DPMBinaryContract,
+  FreeResponseContract,
+  NumericContract,
 } from './contract'
 import { User } from './user'
 import { LiquidityProvision } from './liquidity-provision'
@ -23,7 +21,7 @@ export const HOUSE_LIQUIDITY_PROVIDER_ID = 'IPTOzEqrpkWmEzh6hwvAyY9PqFb2' // @Ma

 export function getCpmmInitialLiquidity(
  providerId: string,
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMBinaryContract,
  anteId: string,
  amount: number
 ) {
@ -47,7 +45,7 @@ export function getCpmmInitialLiquidity(

 export function getAnteBets(
  creator: User,
-  contract: FullContract<DPM, Binary>,
+  contract: DPMBinaryContract,
  yesAnteId: string,
  noAnteId: string
 ) {
@ -89,7 +87,7 @@ export function getAnteBets(

 export function getFreeAnswerAnte(
  anteBettorId: string,
-  contract: FullContract<DPM, FreeResponse>,
+  contract: FreeResponseContract,
  anteBetId: string
 ) {
  const { totalBets, totalShares } = contract
@ -117,7 +115,7 @@ export function getFreeAnswerAnte(

 export function getNumericAnte(
  anteBettorId: string,
-  contract: FullContract<DPM, Numeric>,
+  contract: NumericContract,
  ante: number,
  newBetId: string
 ) {
--- a/common/calculate-cpmm.ts
+++ b/common/calculate-cpmm.ts
@ -1,6 +1,6 @@
 import { sum, groupBy, mapValues, sumBy } from 'lodash'

-import { Binary, CPMM, FullContract } from './contract'
+import { CPMMContract } from './contract'
 import { CREATOR_FEE, Fees, LIQUIDITY_FEE, noFees, PLATFORM_FEE } from './fees'
 import { LiquidityProvision } from './liquidity-provision'
 import { addObjects } from './util/object'
@ -14,7 +14,7 @@ export function getCpmmProbability(
 }

 export function getCpmmProbabilityAfterBetBeforeFees(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  outcome: string,
  bet: number
 ) {
@ -31,7 +31,7 @@ export function getCpmmProbabilityAfterBetBeforeFees(
 }

 export function getCpmmOutcomeProbabilityAfterBet(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  outcome: string,
  bet: number
 ) {
@ -59,7 +59,7 @@ function calculateCpmmShares(
 }

 export function getCpmmLiquidityFee(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  bet: number,
  outcome: string
 ) {
@ -78,7 +78,7 @@ export function getCpmmLiquidityFee(
 }

 export function calculateCpmmSharesAfterFee(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  bet: number,
  outcome: string
 ) {
@ -89,7 +89,7 @@ export function calculateCpmmSharesAfterFee(
 }

 export function calculateCpmmPurchase(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  bet: number,
  outcome: string
 ) {
@ -133,7 +133,7 @@ function sellSharesK(
 }

 function calculateCpmmShareValue(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  shares: number,
  outcome: 'YES' | 'NO'
 ) {
@ -168,7 +168,7 @@ function calculateCpmmShareValue(
 }

 export function calculateCpmmSale(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  shares: number,
  outcome: string
 ) {
@ -222,7 +222,7 @@ export function calculateCpmmSale(
 }

 export function getCpmmProbabilityAfterSale(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  shares: number,
  outcome: 'YES' | 'NO'
 ) {
@ -261,7 +261,7 @@ export function addCpmmLiquidity(
 }

 export function getCpmmLiquidityPoolWeights(
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  liquidities: LiquidityProvision[]
 ) {
  const { p } = contract
@ -291,7 +291,7 @@ export function getCpmmLiquidityPoolWeights(
 }

 // export function removeCpmmLiquidity(
-//   contract: FullContract<CPMM, Binary>,
+//   contract: CPMMContract,
 //   liquidity: number
 // ) {
 //   const { YES, NO } = contract.pool
--- a/common/calculate-dpm.ts
+++ b/common/calculate-dpm.ts
@ -1,13 +1,6 @@
 import { cloneDeep, range, sum, sumBy, sortBy, mapValues } from 'lodash'
 import { Bet, NumericBet } from './bet'
-import {
-  Binary,
-  DPM,
-  FreeResponse,
-  FullContract,
-  Numeric,
-  NumericContract,
-} from './contract'
+import { DPMContract, DPMBinaryContract, NumericContract } from './contract'
 import { DPM_FEES } from './fees'
 import { normpdf } from '../common/util/math'
 import { addObjects } from './util/object'
@ -202,7 +195,7 @@ export function calculateDpmRawShareValue(
 }

 export function calculateDpmMoneyRatio(
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bet: Bet,
  shareValue: number
 ) {
@ -228,10 +221,7 @@ export function calculateDpmMoneyRatio(
  return actual / expected
 }

-export function calculateDpmShareValue(
-  contract: FullContract<DPM, any>,
-  bet: Bet
-) {
+export function calculateDpmShareValue(contract: DPMContract, bet: Bet) {
  const { pool, totalShares } = contract
  const { shares, outcome } = bet

@ -243,17 +233,14 @@ export function calculateDpmShareValue(
  return adjShareValue
 }

-export function calculateDpmSaleAmount(
-  contract: FullContract<DPM, any>,
-  bet: Bet
-) {
+export function calculateDpmSaleAmount(contract: DPMContract, bet: Bet) {
  const { amount } = bet
  const winnings = calculateDpmShareValue(contract, bet)
  return deductDpmFees(amount, winnings)
 }

 export function calculateDpmPayout(
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bet: Bet,
  outcome: string
 ) {
@ -263,10 +250,7 @@ export function calculateDpmPayout(
  return calculateStandardDpmPayout(contract, bet, outcome)
 }

-export function calculateDpmCancelPayout(
-  contract: FullContract<DPM, any>,
-  bet: Bet
-) {
+export function calculateDpmCancelPayout(contract: DPMContract, bet: Bet) {
  const { totalBets, pool } = contract
  const betTotal = sum(Object.values(totalBets))
  const poolTotal = sum(Object.values(pool))
@ -275,7 +259,7 @@ export function calculateDpmCancelPayout(
 }

 export function calculateStandardDpmPayout(
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bet: Bet,
  outcome: string
 ) {
@ -308,7 +292,7 @@ export function calculateStandardDpmPayout(
 }

 export function calculateDpmPayoutAfterCorrectBet(
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bet: Bet
 ) {
  const { totalShares, pool, totalBets, outcomeType } = contract
@ -338,13 +322,10 @@ export function calculateDpmPayoutAfterCorrectBet(
        : outcomeType,
  }

-  return calculateStandardDpmPayout(newContract, bet, outcome)
+  return calculateStandardDpmPayout(newContract as any, bet, outcome)
 }

-function calculateMktDpmPayout(
-  contract: FullContract<DPM, Binary | FreeResponse | Numeric>,
-  bet: Bet
-) {
+function calculateMktDpmPayout(contract: DPMContract, bet: Bet) {
  if (contract.outcomeType === 'BINARY')
    return calculateBinaryMktDpmPayout(contract, bet)

@ -389,10 +370,7 @@ function calculateMktDpmPayout(
  return deductDpmFees(amount, winnings)
 }

-function calculateBinaryMktDpmPayout(
-  contract: FullContract<DPM, Binary>,
-  bet: Bet
-) {
+function calculateBinaryMktDpmPayout(contract: DPMBinaryContract, bet: Bet) {
  const { resolutionProbability, totalShares, phantomShares } = contract
  const p =
    resolutionProbability !== undefined
@ -413,7 +391,7 @@ function calculateBinaryMktDpmPayout(
  return deductDpmFees(amount, winnings)
 }

-export function resolvedDpmPayout(contract: FullContract<DPM, any>, bet: Bet) {
+export function resolvedDpmPayout(contract: DPMContract, bet: Bet) {
  if (contract.resolution)
    return calculateDpmPayout(contract, bet, contract.resolution)
  throw new Error('Contract was not resolved')
--- a/common/calculate-fixed-payouts.ts
+++ b/common/calculate-fixed-payouts.ts
@ -1,9 +1,9 @@
 import { Bet } from './bet'
 import { getProbability } from './calculate'
-import { Binary, FixedPayouts, FullContract } from './contract'
+import { CPMMContract } from './contract'

 export function calculateFixedPayout(
-  contract: FullContract<FixedPayouts, Binary>,
+  contract: CPMMContract,
  bet: Bet,
  outcome: string
 ) {
@ -23,10 +23,7 @@ export function calculateStandardFixedPayout(bet: Bet, outcome: string) {
  return shares
 }

-function calculateFixedMktPayout(
-  contract: FullContract<FixedPayouts, Binary>,
-  bet: Bet
-) {
+function calculateFixedMktPayout(contract: CPMMContract, bet: Bet) {
  const { resolutionProbability } = contract
  const p =
    resolutionProbability !== undefined
--- a/common/calculate.ts
+++ b/common/calculate.ts
@ -18,24 +18,15 @@ import {
  getDpmProbabilityAfterSale,
 } from './calculate-dpm'
 import { calculateFixedPayout } from './calculate-fixed-payouts'
-import {
-  Binary,
-  Contract,
-  CPMM,
-  DPM,
-  FreeResponseContract,
-  FullContract,
-} from './contract'
+import { Contract, BinaryContract, FreeResponseContract } from './contract'

-export function getProbability(contract: FullContract<DPM | CPMM, Binary>) {
+export function getProbability(contract: BinaryContract) {
  return contract.mechanism === 'cpmm-1'
    ? getCpmmProbability(contract.pool, contract.p)
    : getDpmProbability(contract.totalShares)
 }

-export function getInitialProbability(
-  contract: FullContract<DPM | CPMM, Binary>
-) {
+export function getInitialProbability(contract: BinaryContract) {
  if (contract.initialProbability) return contract.initialProbability

  if (contract.mechanism === 'dpm-2' || (contract as any).totalShares)
@ -59,11 +50,7 @@ export function getOutcomeProbabilityAfterBet(
  bet: number
 ) {
  return contract.mechanism === 'cpmm-1'
-    ? getCpmmOutcomeProbabilityAfterBet(
-        contract as FullContract<CPMM, Binary>,
-        outcome,
-        bet
-      )
+    ? getCpmmOutcomeProbabilityAfterBet(contract, outcome, bet)
    : getDpmOutcomeProbabilityAfterBet(contract.totalShares, outcome, bet)
 }

@ -73,11 +60,7 @@ export function calculateShares(
  betChoice: string
 ) {
  return contract.mechanism === 'cpmm-1'
-    ? calculateCpmmSharesAfterFee(
-        contract as FullContract<CPMM, Binary>,
-        bet,
-        betChoice
-      )
+    ? calculateCpmmSharesAfterFee(contract, bet, betChoice)
    : calculateDpmShares(contract.totalShares, bet, betChoice)
 }

@ -99,11 +82,7 @@ export function getProbabilityAfterSale(
  shares: number
 ) {
  return contract.mechanism === 'cpmm-1'
-    ? getCpmmProbabilityAfterSale(
-        contract as FullContract<CPMM, Binary>,
-        shares,
-        outcome as 'YES' | 'NO'
-      )
+    ? getCpmmProbabilityAfterSale(contract, shares, outcome as 'YES' | 'NO')
    : getDpmProbabilityAfterSale(contract.totalShares, outcome, shares)
 }

--- a/common/contract.ts
+++ b/common/contract.ts
@ -1,10 +1,15 @@
 import { Answer } from './answer'
 import { Fees } from './fees'

-export type FullContract<
-  M extends DPM | CPMM,
-  T extends Binary | Multi | FreeResponse | Numeric
-> = {
+export type AnyMechanism = DPM | CPMM
+export type AnyOutcomeType = Binary | Multi | FreeResponse | Numeric
+export type AnyContractType =
+  | (CPMM & Binary)
+  | (DPM & Binary)
+  | (DPM & (Multi | FreeResponse))
+  | (DPM & Numeric)
+
+export type Contract<T extends AnyContractType = AnyContractType> = {
  id: string
  slug: string // auto-generated; must be unique

@ -36,16 +41,15 @@ export type FullContract<
  volume7Days: number

  collectedFees: Fees
-} & M &
-  T
+} & T

-export type Contract = FullContract<
-  DPM | CPMM,
-  Binary | Multi | FreeResponse | Numeric
->
-export type BinaryContract = FullContract<DPM | CPMM, Binary>
-export type FreeResponseContract = FullContract<DPM | CPMM, FreeResponse>
-export type NumericContract = FullContract<DPM, Numeric>
+export type BinaryContract = Contract & Binary
+export type NumericContract = Contract & Numeric
+export type FreeResponseContract = Contract & FreeResponse
+export type DPMContract = Contract & DPM
+export type CPMMContract = Contract & CPMM
+export type DPMBinaryContract = BinaryContract & DPM
+export type CPMMBinaryContract = BinaryContract & CPMM

 export type DPM = {
  mechanism: 'dpm-2'
@ -63,8 +67,6 @@ export type CPMM = {
  totalLiquidity: number // in M$
 }

-export type FixedPayouts = CPMM
-
 export type Binary = {
  outcomeType: 'BINARY'
  initialProbability: number
@ -94,7 +96,7 @@ export type Numeric = {
  resolutionValue?: number
 }

-export type outcomeType = 'BINARY' | 'MULTI' | 'FREE_RESPONSE' | 'NUMERIC'
+export type outcomeType = AnyOutcomeType['outcomeType']
 export const OUTCOME_TYPES = [
  'BINARY',
  'MULTI',
--- a/common/new-bet.ts
+++ b/common/new-bet.ts
@ -10,12 +10,9 @@ import {
 } from './calculate-dpm'
 import { calculateCpmmPurchase, getCpmmProbability } from './calculate-cpmm'
 import {
-  Binary,
-  CPMM,
-  DPM,
-  FreeResponse,
-  FullContract,
-  Multi,
+  CPMMBinaryContract,
+  DPMBinaryContract,
+  FreeResponseContract,
  NumericContract,
 } from './contract'
 import { noFees } from './fees'
@ -35,7 +32,7 @@ export type BetInfo = {
 export const getNewBinaryCpmmBetInfo = (
  outcome: 'YES' | 'NO',
  amount: number,
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMBinaryContract,
  loanAmount: number
 ) => {
  const { shares, newPool, newP, fees } = calculateCpmmPurchase(
@ -69,7 +66,7 @@ export const getNewBinaryCpmmBetInfo = (
 export const getNewBinaryDpmBetInfo = (
  outcome: 'YES' | 'NO',
  amount: number,
-  contract: FullContract<DPM, Binary>,
+  contract: DPMBinaryContract,
  loanAmount: number
 ) => {
  const { YES: yesPool, NO: noPool } = contract.pool
@ -116,7 +113,7 @@ export const getNewBinaryDpmBetInfo = (
 export const getNewMultiBetInfo = (
  outcome: string,
  amount: number,
-  contract: FullContract<DPM, Multi | FreeResponse>,
+  contract: FreeResponseContract,
  loanAmount: number
 ) => {
  const { pool, totalShares, totalBets } = contract
--- a/common/payouts-dpm.ts
+++ b/common/payouts-dpm.ts
@ -2,14 +2,11 @@ import { sum, groupBy, sumBy, mapValues } from 'lodash'

 import { Bet, NumericBet } from './bet'
 import { deductDpmFees, getDpmProbability } from './calculate-dpm'
-import { DPM, FreeResponse, FullContract, Multi } from './contract'
+import { DPMContract, FreeResponseContract } from './contract'
 import { DPM_CREATOR_FEE, DPM_FEES, DPM_PLATFORM_FEE } from './fees'
 import { addObjects } from './util/object'

-export const getDpmCancelPayouts = (
-  contract: FullContract<DPM, any>,
-  bets: Bet[]
-) => {
+export const getDpmCancelPayouts = (contract: DPMContract, bets: Bet[]) => {
  const { pool } = contract
  const poolTotal = sum(Object.values(pool))
  console.log('resolved N/A, pool M$', poolTotal)
@ -31,7 +28,7 @@ export const getDpmCancelPayouts = (

 export const getDpmStandardPayouts = (
  outcome: string,
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bets: Bet[]
 ) => {
  const winningBets = bets.filter((bet) => bet.outcome === outcome)
@ -78,7 +75,7 @@ export const getDpmStandardPayouts = (

 export const getNumericDpmPayouts = (
  outcome: string,
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bets: NumericBet[]
 ) => {
  const totalShares = sumBy(bets, (bet) => bet.allOutcomeShares[outcome] ?? 0)
@ -129,7 +126,7 @@ export const getNumericDpmPayouts = (
 }

 export const getDpmMktPayouts = (
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  bets: Bet[],
  resolutionProbability?: number
 ) => {
@ -183,7 +180,7 @@ export const getDpmMktPayouts = (

 export const getPayoutsMultiOutcome = (
  resolutions: { [outcome: string]: number },
-  contract: FullContract<DPM, Multi | FreeResponse>,
+  contract: FreeResponseContract,
  bets: Bet[]
 ) => {
  const poolTotal = sum(Object.values(contract.pool))
--- a/common/payouts-fixed.ts
+++ b/common/payouts-fixed.ts
@ -3,7 +3,7 @@ import { sum } from 'lodash'
 import { Bet } from './bet'
 import { getProbability } from './calculate'
 import { getCpmmLiquidityPoolWeights } from './calculate-cpmm'
-import { Binary, CPMM, FixedPayouts, FullContract } from './contract'
+import { CPMMContract } from './contract'
 import { noFees } from './fees'
 import { LiquidityProvision } from './liquidity-provision'

@ -30,7 +30,7 @@ export const getFixedCancelPayouts = (

 export const getStandardFixedPayouts = (
  outcome: string,
-  contract: FullContract<FixedPayouts, Binary>,
+  contract: CPMMContract,
  bets: Bet[],
  liquidities: LiquidityProvision[]
 ) => {
@ -65,7 +65,7 @@ export const getStandardFixedPayouts = (
 }

 export const getLiquidityPoolPayouts = (
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  outcome: string,
  liquidities: LiquidityProvision[]
 ) => {
@ -81,7 +81,7 @@ export const getLiquidityPoolPayouts = (
 }

 export const getMktFixedPayouts = (
-  contract: FullContract<FixedPayouts, Binary>,
+  contract: CPMMContract,
  bets: Bet[],
  liquidities: LiquidityProvision[],
  resolutionProbability?: number
@ -116,7 +116,7 @@ export const getMktFixedPayouts = (
 }

 export const getLiquidityPoolProbPayouts = (
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  p: number,
  liquidities: LiquidityProvision[]
 ) => {
--- a/common/payouts.ts
+++ b/common/payouts.ts
@ -1,15 +1,7 @@
 import { sumBy, groupBy, mapValues } from 'lodash'

 import { Bet, NumericBet } from './bet'
-import {
-  Binary,
-  Contract,
-  DPM,
-  FixedPayouts,
-  FreeResponse,
-  FullContract,
-  Multi,
-} from './contract'
+import { Contract, CPMMBinaryContract, DPMContract } from './contract'
 import { Fees } from './fees'
 import { LiquidityProvision } from './liquidity-provision'
 import {
@ -55,7 +47,7 @@ export type PayoutInfo = {
 }

 export const getPayouts = (
-  outcome: string,
+  outcome: string | undefined,
  resolutions: {
    [outcome: string]: number
  },
@ -73,7 +65,6 @@ export const getPayouts = (
      resolutionProbability
    )
  }
-
  return getDpmPayouts(
    outcome,
    resolutions,
@ -84,8 +75,8 @@ export const getPayouts = (
 }

 export const getFixedPayouts = (
-  outcome: string,
-  contract: FullContract<FixedPayouts, Binary>,
+  outcome: string | undefined,
+  contract: CPMMBinaryContract,
  bets: Bet[],
  liquidities: LiquidityProvision[],
  resolutionProbability?: number
@ -108,11 +99,11 @@ export const getFixedPayouts = (
 }

 export const getDpmPayouts = (
-  outcome: string,
+  outcome: string | undefined,
  resolutions: {
    [outcome: string]: number
  },
-  contract: Contract,
+  contract: DPMContract,
  bets: Bet[],
  resolutionProbability?: number
 ): PayoutInfo => {
@ -125,13 +116,10 @@ export const getDpmPayouts = (

    case 'MKT':
      return contract.outcomeType === 'FREE_RESPONSE'
-        ? getPayoutsMultiOutcome(
-            resolutions,
-            contract as FullContract<DPM, Multi | FreeResponse>,
-            openBets
-          )
+        ? getPayoutsMultiOutcome(resolutions, contract, openBets)
        : getDpmMktPayouts(contract, openBets, resolutionProbability)
    case 'CANCEL':
+    case undefined:
      return getDpmCancelPayouts(contract, openBets)

    default:
--- a/common/scoring.ts
+++ b/common/scoring.ts
@ -1,7 +1,7 @@
 import { groupBy, sumBy, mapValues, partition } from 'lodash'

 import { Bet } from './bet'
-import { Binary, Contract, FullContract } from './contract'
+import { Contract } from './contract'
 import { getPayouts } from './payouts'

 export function scoreCreators(contracts: Contract[]) {
@ -24,23 +24,24 @@ export function scoreTraders(contracts: Contract[], bets: Bet[][]) {
  return userScores
 }

-export function scoreUsersByContract(
-  contract: FullContract<any, Binary>,
-  bets: Bet[]
-) {
-  const { resolution, resolutionProbability } = contract
+export function scoreUsersByContract(contract: Contract, bets: Bet[]) {
+  const { resolution } = contract
+  const resolutionProb =
+    contract.outcomeType == 'BINARY'
+      ? contract.resolutionProbability
+      : undefined

  const [closedBets, openBets] = partition(
    bets,
    (bet) => bet.isSold || bet.sale
  )
  const { payouts: resolvePayouts } = getPayouts(
-    resolution,
+    resolution as string,
    {},
    contract,
    openBets,
    [],
-    resolutionProbability
+    resolutionProb
  )

  const salePayouts = closedBets.map((bet) => {
--- a/common/sell-bet.ts
+++ b/common/sell-bet.ts
@ -5,14 +5,14 @@ import {
  deductDpmFees,
 } from './calculate-dpm'
 import { calculateCpmmSale, getCpmmProbability } from './calculate-cpmm'
-import { Binary, DPM, CPMM, FullContract } from './contract'
+import { CPMMContract, DPMContract } from './contract'
 import { DPM_CREATOR_FEE, DPM_PLATFORM_FEE, Fees } from './fees'
 import { User } from './user'

 export const getSellBetInfo = (
  user: User,
  bet: Bet,
-  contract: FullContract<DPM, any>,
+  contract: DPMContract,
  newBetId: string
 ) => {
  const { pool, totalShares, totalBets } = contract
@ -87,7 +87,7 @@ export const getCpmmSellBetInfo = (
  user: User,
  shares: number,
  outcome: 'YES' | 'NO',
-  contract: FullContract<CPMM, Binary>,
+  contract: CPMMContract,
  prevLoanAmount: number,
  newBetId: string
 ) => {
--- a/functions/src/create-answer.ts
+++ b/functions/src/create-answer.ts
@ -1,12 +1,7 @@
 import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'

-import {
-  Contract,
-  DPM,
-  FreeResponse,
-  FullContract,
-} from '../../common/contract'
+import { Contract } from '../../common/contract'
 import { User } from '../../common/user'
 import { getNewMultiBetInfo } from '../../common/new-bet'
 import { Answer, MAX_ANSWER_LENGTH } from '../../common/answer'
@ -96,12 +91,7 @@ export const createAnswer = functions.runWith({ minInstances: 1 }).https.onCall(
      const loanAmount = 0

      const { newBet, newPool, newTotalShares, newTotalBets } =
-        getNewMultiBetInfo(
-          answerId,
-          amount,
-          contract as FullContract<DPM, FreeResponse>,
-          loanAmount
-        )
+        getNewMultiBetInfo(answerId, amount, contract, loanAmount)

      const newBalance = user.balance - amount
      const betDoc = firestore.collection(`contracts/${contractId}/bets`).doc()
--- a/functions/src/create-contract.ts
+++ b/functions/src/create-contract.ts
@ -2,16 +2,13 @@ import * as admin from 'firebase-admin'
 import { z } from 'zod'

 import {
-  Binary,
+  CPMMBinaryContract,
  Contract,
-  CPMM,
-  DPM,
-  FreeResponse,
-  FullContract,
+  FreeResponseContract,
  MAX_DESCRIPTION_LENGTH,
  MAX_QUESTION_LENGTH,
  MAX_TAG_LENGTH,
-  Numeric,
+  NumericContract,
  OUTCOME_TYPES,
 } from '../../common/contract'
 import { slugify } from '../../common/util/slugify'
@ -22,7 +19,6 @@ import { APIError, newEndpoint, validate, zTimestamp } from './api'

 import {
  FIXED_ANTE,
-  getAnteBets,
  getCpmmInitialLiquidity,
  getFreeAnswerAnte,
  getNumericAnte,
@ -117,30 +113,14 @@ export const createContract = newEndpoint(['POST'], async (req, [user, _]) => {

  const providerId = isFree ? HOUSE_LIQUIDITY_PROVIDER_ID : user.id

-  if (outcomeType === 'BINARY' && contract.mechanism === 'dpm-2') {
-    const yesBetDoc = firestore
-      .collection(`contracts/${contract.id}/bets`)
-      .doc()
-
-    const noBetDoc = firestore.collection(`contracts/${contract.id}/bets`).doc()
-
-    const { yesBet, noBet } = getAnteBets(
-      user,
-      contract as FullContract<DPM, Binary>,
-      yesBetDoc.id,
-      noBetDoc.id
-    )
-
-    await yesBetDoc.set(yesBet)
-    await noBetDoc.set(noBet)
-  } else if (outcomeType === 'BINARY') {
+  if (outcomeType === 'BINARY') {
    const liquidityDoc = firestore
      .collection(`contracts/${contract.id}/liquidity`)
      .doc()

    const lp = getCpmmInitialLiquidity(
      providerId,
-      contract as FullContract<CPMM, Binary>,
+      contract as CPMMBinaryContract,
      liquidityDoc.id,
      ante
    )
@ -160,7 +140,7 @@ export const createContract = newEndpoint(['POST'], async (req, [user, _]) => {

    const anteBet = getFreeAnswerAnte(
      providerId,
-      contract as FullContract<DPM, FreeResponse>,
+      contract as FreeResponseContract,
      anteBetDoc.id
    )
    await anteBetDoc.set(anteBet)
@ -171,7 +151,7 @@ export const createContract = newEndpoint(['POST'], async (req, [user, _]) => {

    const anteBet = getNumericAnte(
      providerId,
-      contract as FullContract<DPM, Numeric>,
+      contract as NumericContract,
      ante,
      anteBetDoc.id
    )
--- a/functions/src/redeem-shares.ts
+++ b/functions/src/redeem-shares.ts
@ -4,7 +4,7 @@ import { partition, sumBy } from 'lodash'
 import { Bet } from '../../common/bet'
 import { getProbability } from '../../common/calculate'

-import { Binary, CPMM, FullContract } from '../../common/contract'
+import { Contract } from '../../common/contract'
 import { noFees } from '../../common/fees'
 import { User } from '../../common/user'

@ -15,7 +15,7 @@ export const redeemShares = async (userId: string, contractId: string) => {
    if (!contractSnap.exists)
      return { status: 'error', message: 'Invalid contract' }

-    const contract = contractSnap.data() as FullContract<CPMM, Binary>
+    const contract = contractSnap.data() as Contract
    if (contract.outcomeType !== 'BINARY' || contract.mechanism !== 'cpmm-1')
      return { status: 'success' }

--- a/functions/src/scripts/correct-bet-probability.ts
+++ b/functions/src/scripts/correct-bet-probability.ts
@ -6,14 +6,14 @@ initAdmin()

 import { Bet } from '../../../common/bet'
 import { getDpmProbability } from '../../../common/calculate-dpm'
-import { Binary, Contract, DPM, FullContract } from '../../../common/contract'
+import { DPMBinaryContract } from '../../../common/contract'

 type DocRef = admin.firestore.DocumentReference
 const firestore = admin.firestore()

 async function migrateContract(
  contractRef: DocRef,
-  contract: FullContract<DPM, Binary>
+  contract: DPMBinaryContract
 ) {
  const bets = await contractRef
    .collection('bets')
@ -34,9 +34,7 @@ async function migrateContract(

 async function migrateContracts() {
  const snapshot = await firestore.collection('contracts').get()
-  const contracts = snapshot.docs.map(
-    (doc) => doc.data() as FullContract<DPM, Binary>
-  )
+  const contracts = snapshot.docs.map((doc) => doc.data() as DPMBinaryContract)

  console.log('Loaded contracts', contracts.length)

--- a/functions/src/scripts/migrate-to-cfmm.ts
+++ b/functions/src/scripts/migrate-to-cfmm.ts
@ -5,18 +5,15 @@ import { initAdmin } from './script-init'
 initAdmin()

 import {
-  Binary,
  Contract,
-  CPMM,
-  DPM,
-  FullContract,
+  DPMBinaryContract,
+  CPMMBinaryContract,
 } from '../../../common/contract'
 import { Bet } from '../../../common/bet'
 import {
  calculateDpmPayout,
  getDpmProbability,
 } from '../../../common/calculate-dpm'
-import { User } from '../../../common/user'
 import { getCpmmInitialLiquidity } from '../../../common/antes'
 import { noFees } from '../../../common/fees'
 import { addObjects } from '../../../common/util/object'
@ -28,7 +25,7 @@ const firestore = admin.firestore()
 async function recalculateContract(contractRef: DocRef, isCommit = false) {
  await firestore.runTransaction(async (transaction) => {
    const contractDoc = await transaction.get(contractRef)
-    const contract = contractDoc.data() as FullContract<DPM, Binary>
+    const contract = contractDoc.data() as DPMBinaryContract

    if (!contract?.slug) {
      console.log('missing slug; id=', contractRef.id)
@ -110,7 +107,7 @@ async function recalculateContract(contractRef: DocRef, isCommit = false) {
      {
        ...contract,
        ...contractUpdate,
-      } as FullContract<CPMM, Binary>,
+      } as CPMMBinaryContract,
      liquidityDocRef.id,
      ante
    )
--- a/functions/src/scripts/migrate-to-dpm-2.ts
+++ b/functions/src/scripts/migrate-to-dpm-2.ts
@ -4,7 +4,7 @@ import { sortBy, sumBy } from 'lodash'
 import { initAdmin } from './script-init'
 initAdmin()

-import { Binary, Contract, DPM, FullContract } from '../../../common/contract'
+import { Contract, DPMBinaryContract } from '../../../common/contract'
 import { Bet } from '../../../common/bet'
 import {
  calculateDpmShares,
@ -32,7 +32,7 @@ async function recalculateContract(

  await firestore.runTransaction(async (transaction) => {
    const contractDoc = await transaction.get(contractRef)
-    const contract = contractDoc.data() as FullContract<DPM, Binary>
+    const contract = contractDoc.data() as DPMBinaryContract

    const betDocs = await transaction.get(contractRef.collection('bets'))
    const bets = sortBy(
--- a/functions/src/sell-shares.ts
+++ b/functions/src/sell-shares.ts
@ -2,7 +2,7 @@ import { partition, sumBy } from 'lodash'
 import * as admin from 'firebase-admin'
 import * as functions from 'firebase-functions'

-import { Binary, CPMM, FullContract } from '../../common/contract'
+import { BinaryContract } from '../../common/contract'
 import { User } from '../../common/user'
 import { getCpmmSellBetInfo } from '../../common/sell-bet'
 import { addObjects, removeUndefinedProps } from '../../common/util/object'
@ -35,7 +35,7 @@ export const sellShares = functions.runWith({ minInstances: 1 }).https.onCall(
      const contractSnap = await transaction.get(contractDoc)
      if (!contractSnap.exists)
        return { status: 'error', message: 'Invalid contract' }
-      const contract = contractSnap.data() as FullContract<CPMM, Binary>
+      const contract = contractSnap.data() as BinaryContract
      const { closeTime, mechanism, collectedFees, volume } = contract

      if (mechanism !== 'cpmm-1')
--- a/web/components/answers/answer-bet-panel.tsx
+++ b/web/components/answers/answer-bet-panel.tsx
@ -3,7 +3,7 @@ import { useEffect, useRef, useState } from 'react'
 import { XIcon } from '@heroicons/react/solid'

 import { Answer } from 'common/answer'
-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { FreeResponseContract } from 'common/contract'
 import { BuyAmountInput } from '../amount-input'
 import { Col } from '../layout/col'
 import { APIError, placeBet } from 'web/lib/firebase/api-call'
@ -27,7 +27,7 @@ import { Bet } from 'common/bet'

 export function AnswerBetPanel(props: {
  answer: Answer
-  contract: FullContract<DPM, FreeResponse>
+  contract: FreeResponseContract
  closePanel: () => void
  className?: string
  isModal?: boolean
--- a/web/components/answers/answer-item.tsx
+++ b/web/components/answers/answer-item.tsx
@ -1,7 +1,7 @@
 import clsx from 'clsx'

 import { Answer } from 'common/answer'
-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { FreeResponseContract } from 'common/contract'
 import { Col } from '../layout/col'
 import { Row } from '../layout/row'
 import { Avatar } from '../avatar'
@ -13,7 +13,7 @@ import { Linkify } from '../linkify'

 export function AnswerItem(props: {
  answer: Answer
-  contract: FullContract<DPM, FreeResponse>
+  contract: FreeResponseContract
  showChoice: 'radio' | 'checkbox' | undefined
  chosenProb: number | undefined
  totalChosenProb?: number
--- a/web/components/answers/answer-resolve-panel.tsx
+++ b/web/components/answers/answer-resolve-panel.tsx
@ -2,7 +2,7 @@ import clsx from 'clsx'
 import { sum, mapValues } from 'lodash'
 import { useState } from 'react'

-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { Contract, FreeResponse } from 'common/contract'
 import { Col } from '../layout/col'
 import { resolveMarket } from 'web/lib/firebase/fn-call'
 import { Row } from '../layout/row'
@ -11,7 +11,7 @@ import { ResolveConfirmationButton } from '../confirmation-button'
 import { removeUndefinedProps } from 'common/util/object'

 export function AnswerResolvePanel(props: {
-  contract: FullContract<DPM, FreeResponse>
+  contract: Contract & FreeResponse
  resolveOption: 'CHOOSE' | 'CHOOSE_MULTIPLE' | 'CANCEL' | undefined
  setResolveOption: (
    option: 'CHOOSE' | 'CHOOSE_MULTIPLE' | 'CANCEL' | undefined
--- a/web/components/answers/answers-graph.tsx
+++ b/web/components/answers/answers-graph.tsx
@ -5,7 +5,7 @@ import { groupBy, sortBy, sumBy } from 'lodash'
 import { memo } from 'react'

 import { Bet } from 'common/bet'
-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { FreeResponseContract } from 'common/contract'
 import { getOutcomeProbability } from 'common/calculate'
 import { useBets } from 'web/hooks/use-bets'
 import { useWindowSize } from 'web/hooks/use-window-size'
@ -13,7 +13,7 @@ import { useWindowSize } from 'web/hooks/use-window-size'
 const NUM_LINES = 6

 export const AnswersGraph = memo(function AnswersGraph(props: {
-  contract: FullContract<DPM, FreeResponse>
+  contract: FreeResponseContract
  bets: Bet[]
  height?: number
 }) {
@ -161,10 +161,7 @@ function formatTime(time: number, includeTime: boolean) {
  return dayjs(time).format('MMM D')
 }

-const computeProbsByOutcome = (
-  bets: Bet[],
-  contract: FullContract<DPM, FreeResponse>
-) => {
+const computeProbsByOutcome = (bets: Bet[], contract: FreeResponseContract) => {
  const { totalBets } = contract

  const betsByOutcome = groupBy(bets, (bet) => bet.outcome)
--- a/web/components/answers/answers-panel.tsx
+++ b/web/components/answers/answers-panel.tsx
@ -1,7 +1,7 @@
 import { sortBy, partition, sum, uniq } from 'lodash'
 import { useLayoutEffect, useState } from 'react'

-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { FreeResponseContract } from 'common/contract'
 import { Col } from '../layout/col'
 import { useUser } from 'web/hooks/use-user'
 import { getDpmOutcomeProbability } from 'common/calculate-dpm'
@ -25,9 +25,7 @@ import { UserLink } from 'web/components/user-page'
 import { Linkify } from 'web/components/linkify'
 import { BuyButton } from 'web/components/yes-no-selector'

-export function AnswersPanel(props: {
-  contract: FullContract<DPM, FreeResponse>
-}) {
+export function AnswersPanel(props: { contract: FreeResponseContract }) {
  const { contract } = props
  const { creatorId, resolution, resolutions, totalBets } = contract

@ -154,7 +152,7 @@ export function AnswersPanel(props: {
 }

 function getAnswerItems(
-  contract: FullContract<DPM, FreeResponse>,
+  contract: FreeResponseContract,
  answers: Answer[],
  user: User | undefined | null
 ) {
@ -182,7 +180,7 @@ function getAnswerItems(
 }

 function OpenAnswer(props: {
-  contract: FullContract<any, FreeResponse>
+  contract: FreeResponseContract
  answer: Answer
  items: ActivityItem[]
  type: string
--- a/web/components/answers/create-answer-panel.tsx
+++ b/web/components/answers/create-answer-panel.tsx
@ -2,7 +2,7 @@ import clsx from 'clsx'
 import { useState } from 'react'
 import Textarea from 'react-expanding-textarea'

-import { DPM, FreeResponse, FullContract } from 'common/contract'
+import { FreeResponseContract } from 'common/contract'
 import { BuyAmountInput } from '../amount-input'
 import { Col } from '../layout/col'
 import { createAnswer } from 'web/lib/firebase/fn-call'
@ -23,9 +23,7 @@ import { firebaseLogin } from 'web/lib/firebase/users'
 import { Bet } from 'common/bet'
 import { MAX_ANSWER_LENGTH } from 'common/answer'

-export function CreateAnswerPanel(props: {
-  contract: FullContract<DPM, FreeResponse>
-}) {
+export function CreateAnswerPanel(props: { contract: FreeResponseContract }) {
  const { contract } = props
  const user = useUser()
  const [text, setText] = useState('')
--- a/web/components/bet-panel.tsx
+++ b/web/components/bet-panel.tsx
@ -3,7 +3,7 @@ import React, { useEffect, useState } from 'react'
 import { partition, sumBy } from 'lodash'

 import { useUser } from 'web/hooks/use-user'
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract, CPMMBinaryContract } from 'common/contract'
 import { Col } from './layout/col'
 import { Row } from './layout/row'
 import { Spacer } from './layout/spacer'
@ -39,7 +39,7 @@ import { useSaveShares } from './use-save-shares'
 import { SignUpPrompt } from './sign-up-prompt'

 export function BetPanel(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  className?: string
 }) {
  const { contract, className } = props
@ -78,7 +78,7 @@ export function BetPanel(props: {
 }

 export function BetPanelSwitcher(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  className?: string
  title?: string // Set if BetPanel is on a feed modal
  selected?: 'YES' | 'NO'
@ -157,16 +157,19 @@ export function BetPanelSwitcher(props: {
          text={tradeType === 'BUY' ? title ?? 'Place a trade' : 'Sell shares'}
        />

-        {tradeType === 'SELL' && user && sharesOutcome && (
-          <SellPanel
-            contract={contract as FullContract<CPMM, Binary>}
-            shares={yesShares || noShares}
-            sharesOutcome={sharesOutcome}
-            user={user}
-            userBets={userBets ?? []}
-            onSellSuccess={onBetSuccess}
-          />
-        )}
+        {tradeType === 'SELL' &&
+          mechanism == 'cpmm-1' &&
+          user &&
+          sharesOutcome && (
+            <SellPanel
+              contract={contract}
+              shares={yesShares || noShares}
+              sharesOutcome={sharesOutcome}
+              user={user}
+              userBets={userBets ?? []}
+              onSellSuccess={onBetSuccess}
+            />
+          )}

        {tradeType === 'BUY' && (
          <BuyPanel
@ -184,7 +187,7 @@ export function BetPanelSwitcher(props: {
 }

 function BuyPanel(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  user: User | null | undefined
  selected?: 'YES' | 'NO'
  onBuySuccess?: () => void
@ -374,7 +377,7 @@ function BuyPanel(props: {
 }

 export function SellPanel(props: {
-  contract: FullContract<CPMM, Binary>
+  contract: CPMMBinaryContract
  userBets: Bet[]
  shares: number
  sharesOutcome: 'YES' | 'NO'
--- a/web/components/bet-row.tsx
+++ b/web/components/bet-row.tsx
@ -3,7 +3,7 @@ import clsx from 'clsx'

 import { BetPanelSwitcher } from './bet-panel'
 import { YesNoSelector } from './yes-no-selector'
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { Modal } from './layout/modal'
 import { SellButton } from './sell-button'
 import { useUser } from 'web/hooks/use-user'
@ -12,7 +12,7 @@ import { useSaveShares } from './use-save-shares'

 // Inline version of a bet panel. Opens BetPanel in a new modal.
 export default function BetRow(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  className?: string
  btnClassName?: string
  betPanelClassName?: string
--- a/web/components/bets-list.tsx
+++ b/web/components/bets-list.tsx
@ -255,7 +255,6 @@ function MyContractBets(props: {
  const [collapsed, setCollapsed] = useState(true)

  const isBinary = outcomeType === 'BINARY'
-  const probPercent = getBinaryProbPercent(contract)

  const { payout, profit, profitPercent, invested } = getContractBetMetrics(
    contract,
@ -292,24 +291,27 @@ function MyContractBets(props: {
          </Row>

          <Row className="flex-1 items-center gap-2 text-sm text-gray-500">
-            {(isBinary || resolution) && (
+            {resolution ? (
              <>
-                {resolution ? (
-                  <div>
-                    Resolved{' '}
-                    <OutcomeLabel
-                      outcome={resolution}
-                      value={resolutionValue}
-                      contract={contract}
-                      truncate="short"
-                    />
-                  </div>
-                ) : (
-                  <div className="text-primary text-lg">{probPercent}</div>
-                )}
+                <div>
+                  Resolved{' '}
+                  <OutcomeLabel
+                    outcome={resolution}
+                    value={resolutionValue}
+                    contract={contract}
+                    truncate="short"
+                  />
+                </div>
                <div>•</div>
              </>
-            )}
+            ) : isBinary ? (
+              <>
+                <div className="text-primary text-lg">
+                  {getBinaryProbPercent(contract)}
+                </div>
+                <div>•</div>
+              </>
+            ) : null}
            <UserLink
              name={contract.creatorName}
              username={contract.creatorUsername}
--- a/web/components/contract/contract-card.tsx
+++ b/web/components/contract/contract-card.tsx
@ -2,19 +2,12 @@ import clsx from 'clsx'
 import Link from 'next/link'
 import { Row } from '../layout/row'
 import { formatLargeNumber, formatPercent } from 'common/util/format'
-import {
-  Contract,
-  contractPath,
-  getBinaryProbPercent,
-} from 'web/lib/firebase/contracts'
+import { contractPath, getBinaryProbPercent } from 'web/lib/firebase/contracts'
 import { Col } from '../layout/col'
 import {
-  Binary,
-  CPMM,
-  DPM,
-  FreeResponse,
+  Contract,
+  BinaryContract,
  FreeResponseContract,
-  FullContract,
  NumericContract,
 } from 'common/contract'
 import {
@ -83,15 +76,12 @@ export function ContractCard(props: {
            {outcomeType === 'FREE_RESPONSE' &&
              (resolution ? (
                <FreeResponseOutcomeLabel
-                  contract={contract as FreeResponseContract}
+                  contract={contract}
                  resolution={resolution}
                  truncate={'long'}
                />
              ) : (
-                <FreeResponseTopAnswer
-                  contract={contract as FullContract<DPM, FreeResponse>}
-                  truncate="long"
-                />
+                <FreeResponseTopAnswer contract={contract} truncate="long" />
              ))}

            <MiscDetails
@ -114,14 +104,14 @@ export function ContractCard(props: {
              {outcomeType === 'NUMERIC' && (
                <NumericResolutionOrExpectation
                  className="items-center"
-                  contract={contract as NumericContract}
+                  contract={contract}
                />
              )}

              {outcomeType === 'FREE_RESPONSE' && (
                <FreeResponseResolutionOrChance
                  className="self-end text-gray-600"
-                  contract={contract as FullContract<DPM, FreeResponse>}
+                  contract={contract}
                  truncate="long"
                />
              )}
@ -135,7 +125,7 @@ export function ContractCard(props: {
 }

 export function BinaryResolutionOrChance(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  large?: boolean
  className?: string
 }) {
--- a/web/components/contract/contract-overview.tsx
+++ b/web/components/contract/contract-overview.tsx
@ -1,4 +1,4 @@
-import { Contract, tradingAllowed } from 'web/lib/firebase/contracts'
+import { tradingAllowed } from 'web/lib/firebase/contracts'
 import { Col } from '../layout/col'
 import { Spacer } from '../layout/spacer'
 import { ContractProbGraph } from './contract-prob-graph'
@ -16,12 +16,7 @@ import { Bet } from 'common/bet'
 import { Comment } from 'common/comment'
 import BetRow from '../bet-row'
 import { AnswersGraph } from '../answers/answers-graph'
-import {
-  DPM,
-  FreeResponse,
-  FullContract,
-  NumericContract,
-} from 'common/contract'
+import { Contract } from 'common/contract'
 import { ContractDescription } from './contract-description'
 import { ContractDetails } from './contract-details'
 import { ShareMarket } from '../share-market'
@ -58,7 +53,7 @@ export const ContractOverview = (props: {

          {outcomeType === 'NUMERIC' && (
            <NumericResolutionOrExpectation
-              contract={contract as NumericContract}
+              contract={contract}
              className="hidden items-end xl:flex"
            />
          )}
@ -82,9 +77,7 @@ export const ContractOverview = (props: {

        {outcomeType === 'NUMERIC' && (
          <Row className="items-center justify-between gap-4 xl:hidden">
-            <NumericResolutionOrExpectation
-              contract={contract as NumericContract}
-            />
+            <NumericResolutionOrExpectation contract={contract} />
          </Row>
        )}

@ -97,14 +90,9 @@ export const ContractOverview = (props: {
      <Spacer h={4} />
      {isBinary && <ContractProbGraph contract={contract} bets={bets} />}{' '}
      {outcomeType === 'FREE_RESPONSE' && (
-        <AnswersGraph
-          contract={contract as FullContract<DPM, FreeResponse>}
-          bets={bets}
-        />
-      )}
-      {outcomeType === 'NUMERIC' && (
-        <NumericGraph contract={contract as NumericContract} />
+        <AnswersGraph contract={contract} bets={bets} />
      )}
+      {outcomeType === 'NUMERIC' && <NumericGraph contract={contract} />}
      {(contract.description || isCreator) && <Spacer h={6} />}
      {isCreator && <ShareMarket className="px-2" contract={contract} />}
      <ContractDescription
--- a/web/components/contract/contract-prob-graph.tsx
+++ b/web/components/contract/contract-prob-graph.tsx
@ -4,12 +4,12 @@ import dayjs from 'dayjs'
 import { memo } from 'react'
 import { Bet } from 'common/bet'
 import { getInitialProbability } from 'common/calculate'
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { useBetsWithoutAntes } from 'web/hooks/use-bets'
 import { useWindowSize } from 'web/hooks/use-window-size'

 export const ContractProbGraph = memo(function ContractProbGraph(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  bets: Bet[]
  height?: number
 }) {
--- a/web/components/contract/quick-bet.tsx
+++ b/web/components/contract/quick-bet.tsx
@ -5,16 +5,8 @@ import {
  getTopAnswer,
 } from 'common/calculate'
 import { getExpectedValue } from 'common/calculate-dpm'
-import {
-  Contract,
-  FullContract,
-  CPMM,
-  DPM,
-  Binary,
-  NumericContract,
-  FreeResponseContract,
-} from 'common/contract'
 import { User } from 'common/user'
+import { Contract, NumericContract } from 'common/contract'
 import {
  formatLargeNumber,
  formatMoney,
@ -39,12 +31,12 @@ export function QuickBet(props: { contract: Contract; user: User }) {
  const userBets = useUserContractBets(user.id, contract.id)
  const topAnswer =
    contract.outcomeType === 'FREE_RESPONSE'
-      ? getTopAnswer(contract as FreeResponseContract)
+      ? getTopAnswer(contract)
      : undefined

  // TODO: yes/no from useSaveShares doesn't work on numeric contracts
  const { yesFloorShares, noFloorShares } = useSaveShares(
-    contract as FullContract<DPM | CPMM, Binary | FreeResponseContract>,
+    contract,
    userBets,
    topAnswer?.number.toString() || undefined
  )
@ -226,10 +218,10 @@ function QuickOutcomeView(props: {
      display = getBinaryProbPercent(contract)
      break
    case 'NUMERIC':
-      display = formatLargeNumber(getExpectedValue(contract as NumericContract))
+      display = formatLargeNumber(getExpectedValue(contract))
      break
    case 'FREE_RESPONSE': {
-      const topAnswer = getTopAnswer(contract as FreeResponseContract)
+      const topAnswer = getTopAnswer(contract)
      display =
        topAnswer &&
        formatPercent(getOutcomeProbability(contract, topAnswer.id))
@ -257,7 +249,7 @@ function getProb(contract: Contract) {
    : outcomeType === 'FREE_RESPONSE'
    ? getOutcomeProbability(contract, getTopAnswer(contract)?.id || '')
    : outcomeType === 'NUMERIC'
-    ? getNumericScale(contract as NumericContract)
+    ? getNumericScale(contract)
    : 1 // Should not happen
 }

--- a/web/components/feed/activity-items.ts
+++ b/web/components/feed/activity-items.ts
@ -4,7 +4,7 @@ import { Answer } from 'common/answer'
 import { Bet } from 'common/bet'
 import { getOutcomeProbability } from 'common/calculate'
 import { Comment } from 'common/comment'
-import { Contract, DPM, FreeResponse, FullContract } from 'common/contract'
+import { Contract, FreeResponseContract } from 'common/contract'
 import { User } from 'common/user'
 import { mapCommentsByBetId } from 'web/lib/firebase/comments'

@ -188,7 +188,7 @@ function groupBets(
 }

 function getAnswerGroups(
-  contract: FullContract<DPM, FreeResponse>,
+  contract: FreeResponseContract,
  bets: Bet[],
  comments: Comment[],
  user: User | undefined | null,
@ -269,7 +269,7 @@ function getAnswerGroups(
 }

 function getAnswerAndCommentInputGroups(
-  contract: FullContract<DPM, FreeResponse>,
+  contract: FreeResponseContract,
  bets: Bet[],
  comments: Comment[],
  user: User | undefined | null
@ -493,17 +493,11 @@ export function getRecentContractActivityItems(
  const items = []
  if (contract.outcomeType === 'FREE_RESPONSE') {
    items.push(
-      ...getAnswerGroups(
-        contract as FullContract<DPM, FreeResponse>,
-        bets,
-        comments,
-        user,
-        {
-          sortByProb: false,
-          abbreviated: true,
-          reversed: true,
-        }
-      )
+      ...getAnswerGroups(contract, bets, comments, user, {
+        sortByProb: false,
+        abbreviated: true,
+        reversed: true,
+      })
    )
  } else {
    items.push(
@ -587,7 +581,7 @@ export function getSpecificContractActivityItems(
    case 'free-response-comment-answer-groups':
      items.push(
        ...getAnswerAndCommentInputGroups(
-          contract as FullContract<DPM, FreeResponse>,
+          contract as FreeResponseContract,
          bets,
          comments,
          user
--- a/web/components/feed/feed-answer-comment-group.tsx
+++ b/web/components/feed/feed-answer-comment-group.tsx
@ -1,4 +1,3 @@
-import { FreeResponse, FullContract } from 'common/contract'
 import { Answer } from 'common/answer'
 import { ActivityItem } from 'web/components/feed/activity-items'
 import { Bet } from 'common/bet'
@ -26,7 +25,7 @@ import { CopyLinkDateTimeComponent } from 'web/components/feed/copy-link-date-ti
 import { useRouter } from 'next/router'

 export function FeedAnswerCommentGroup(props: {
-  contract: FullContract<any, FreeResponse>
+  contract: any
  answer: Answer
  items: ActivityItem[]
  type: string
--- a/web/components/outcome-label.tsx
+++ b/web/components/outcome-label.tsx
@ -3,16 +3,7 @@ import { ReactNode } from 'react'
 import { Answer } from 'common/answer'
 import { getProbability } from 'common/calculate'
 import { getValueFromBucket } from 'common/calculate-dpm'
-import {
-  Binary,
-  Contract,
-  CPMM,
-  DPM,
-  FreeResponse,
-  FreeResponseContract,
-  FullContract,
-  NumericContract,
-} from 'common/contract'
+import { BinaryContract, Contract, NumericContract } from 'common/contract'
 import { formatPercent } from 'common/util/format'
 import { ClientRender } from './client-render'

@ -36,7 +27,7 @@ export function OutcomeLabel(props: {

  return (
    <FreeResponseOutcomeLabel
-      contract={contract as FullContract<DPM, FreeResponse>}
+      contract={contract}
      resolution={outcome}
      truncate={truncate}
      answerClassName={'font-bold text-base-400'}
@ -56,7 +47,7 @@ export function BinaryOutcomeLabel(props: {
 }

 export function BinaryContractOutcomeLabel(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  resolution: 'YES' | 'NO' | 'CANCEL' | 'MKT'
 }) {
  const { contract, resolution } = props
@ -70,7 +61,7 @@ export function BinaryContractOutcomeLabel(props: {
 }

 export function FreeResponseOutcomeLabel(props: {
-  contract: FreeResponseContract
+  contract: Contract
  resolution: string | 'CANCEL' | 'MKT'
  truncate: 'short' | 'long' | 'none'
  answerClassName?: string
@ -80,8 +71,9 @@ export function FreeResponseOutcomeLabel(props: {
  if (resolution === 'CANCEL') return <CancelLabel />
  if (resolution === 'MKT') return <MultiLabel />

-  const { answers } = contract
-  const chosen = answers?.find((answer) => answer.id === resolution)
+  const answers =
+    contract.outcomeType === 'FREE_RESPONSE' ? contract.answers : []
+  const chosen = answers.find((answer) => answer.id === resolution)
  if (!chosen) return <AnswerNumberLabel number={resolution} />
  return (
    <FreeResponseAnswerToolTip text={chosen.text}>
--- a/web/components/resolution-panel.tsx
+++ b/web/components/resolution-panel.tsx
@ -10,12 +10,12 @@ import { resolveMarket } from 'web/lib/firebase/fn-call'
 import { ProbabilitySelector } from './probability-selector'
 import { DPM_CREATOR_FEE } from 'common/fees'
 import { getProbability } from 'common/calculate'
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { formatMoney } from 'common/util/format'

 export function ResolutionPanel(props: {
  creator: User
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  className?: string
 }) {
  useEffect(() => {
--- a/web/components/sell-button.tsx
+++ b/web/components/sell-button.tsx
@ -1,4 +1,4 @@
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { User } from 'common/user'
 import { useUserContractBets } from 'web/hooks/use-user-bets'
 import { useState } from 'react'
@ -7,7 +7,7 @@ import clsx from 'clsx'
 import { SellSharesModal } from './sell-modal'

 export function SellButton(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  user: User | null | undefined
  sharesOutcome: 'YES' | 'NO' | undefined
  shares: number
@ -40,7 +40,7 @@ export function SellButton(props: {
        {showSellModal && (
          <SellSharesModal
            className={panelClassName}
-            contract={contract as FullContract<CPMM, Binary>}
+            contract={contract}
            user={user}
            userBets={userBets ?? []}
            shares={shares}
--- a/web/components/sell-modal.tsx
+++ b/web/components/sell-modal.tsx
@ -1,4 +1,4 @@
-import { Binary, CPMM, FullContract } from 'common/contract'
+import { CPMMBinaryContract } from 'common/contract'
 import { Bet } from 'common/bet'
 import { User } from 'common/user'
 import { Modal } from './layout/modal'
@ -11,7 +11,7 @@ import clsx from 'clsx'

 export function SellSharesModal(props: {
  className?: string
-  contract: FullContract<CPMM, Binary>
+  contract: CPMMBinaryContract
  userBets: Bet[]
  shares: number
  sharesOutcome: 'YES' | 'NO'
--- a/web/components/sell-row.tsx
+++ b/web/components/sell-row.tsx
@ -1,4 +1,4 @@
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { User } from 'common/user'
 import { useState } from 'react'
 import { Col } from './layout/col'
@ -10,7 +10,7 @@ import { useSaveShares } from './use-save-shares'
 import { SellSharesModal } from './sell-modal'

 export function SellRow(props: {
-  contract: FullContract<DPM | CPMM, Binary>
+  contract: BinaryContract
  user: User | null | undefined
  className?: string
 }) {
@ -61,7 +61,7 @@ export function SellRow(props: {
        </Col>
        {showSellModal && (
          <SellSharesModal
-            contract={contract as FullContract<CPMM, Binary>}
+            contract={contract}
            user={user}
            userBets={userBets ?? []}
            shares={yesShares || noShares}
--- a/web/components/use-save-shares.ts
+++ b/web/components/use-save-shares.ts
@ -1,17 +1,11 @@
-import {
-  Binary,
-  CPMM,
-  DPM,
-  FreeResponseContract,
-  FullContract,
-} from 'common/contract'
+import { Contract } from 'common/contract'
 import { Bet } from 'common/bet'
 import { useEffect, useState } from 'react'
 import { partition, sumBy } from 'lodash'
 import { safeLocalStorage } from 'web/lib/util/local'

 export const useSaveShares = (
-  contract: FullContract<CPMM | DPM, Binary | FreeResponseContract>,
+  contract: Contract,
  userBets: Bet[] | undefined,
  freeResponseAnswerOutcome?: string
 ) => {
--- a/web/lib/firebase/contracts.ts
+++ b/web/lib/firebase/contracts.ts
@ -17,7 +17,7 @@ import { range, sortBy, sum } from 'lodash'

 import { app } from './init'
 import { getValues, listenForValue, listenForValues } from './utils'
-import { Binary, Contract, FullContract } from 'common/contract'
+import { BinaryContract, Contract } from 'common/contract'
 import { getDpmProbability } from 'common/calculate-dpm'
 import { createRNG, shuffle } from 'common/util/random'
 import { getCpmmProbability } from 'common/calculate-cpmm'
@ -63,18 +63,18 @@ export function contractPool(contract: Contract) {
    : 'Empty pool'
 }

-export function getBinaryProb(contract: FullContract<any, Binary>) {
-  const { totalShares, pool, p, resolutionProbability, mechanism } = contract
+export function getBinaryProb(contract: BinaryContract) {
+  const { pool, resolutionProbability, mechanism } = contract

  return (
    resolutionProbability ??
    (mechanism === 'cpmm-1'
-      ? getCpmmProbability(pool, p)
-      : getDpmProbability(totalShares))
+      ? getCpmmProbability(pool, contract.p)
+      : getDpmProbability(contract.totalShares))
  )
 }

-export function getBinaryProbPercent(contract: FullContract<any, Binary>) {
+export function getBinaryProbPercent(contract: BinaryContract) {
  return formatPercent(getBinaryProb(contract))
 }

--- a/web/pages/[username]/[contractSlug].tsx
+++ b/web/pages/[username]/[contractSlug].tsx
@ -30,13 +30,6 @@ import { formatMoney } from 'common/util/format'
 import { useUserById } from 'web/hooks/use-users'
 import { ContractTabs } from 'web/components/contract/contract-tabs'
 import { FirstArgument } from 'common/util/types'
-import {
-  BinaryContract,
-  DPM,
-  FreeResponse,
-  FullContract,
-  NumericContract,
-} from 'common/contract'
 import { contractTextDetails } from 'web/components/contract/contract-details'
 import { useWindowSize } from 'web/hooks/use-window-size'
 import Confetti from 'react-confetti'
@ -143,24 +136,15 @@ export function ContractPageContent(props: FirstArgument<typeof ContractPage>) {
    <Col className="gap-4">
      {allowTrade &&
        (isNumeric ? (
-          <NumericBetPanel
-            className="hidden xl:flex"
-            contract={contract as NumericContract}
-          />
+          <NumericBetPanel className="hidden xl:flex" contract={contract} />
        ) : (
          <BetPanel className="hidden xl:flex" contract={contract} />
        ))}
      {allowResolve &&
        (isNumeric ? (
-          <NumericResolutionPanel
-            creator={user}
-            contract={contract as NumericContract}
-          />
+          <NumericResolutionPanel creator={user} contract={contract} />
        ) : (
-          <ResolutionPanel
-            creator={user}
-            contract={contract as BinaryContract}
-          />
+          <ResolutionPanel creator={user} contract={contract} />
        ))}
    </Col>
  ) : null
@ -205,18 +189,13 @@ export function ContractPageContent(props: FirstArgument<typeof ContractPage>) {
        {outcomeType === 'FREE_RESPONSE' && (
          <>
            <Spacer h={4} />
-            <AnswersPanel
-              contract={contract as FullContract<DPM, FreeResponse>}
-            />
+            <AnswersPanel contract={contract} />
            <Spacer h={4} />
          </>
        )}

        {isNumeric && (
-          <NumericBetPanel
-            className="xl:hidden"
-            contract={contract as NumericContract}
-          />
+          <NumericBetPanel className="xl:hidden" contract={contract} />
        )}

        {isResolved && (
--- a/web/pages/embed/[username]/[contractSlug].tsx
+++ b/web/pages/embed/[username]/[contractSlug].tsx
@ -1,12 +1,5 @@
 import { Bet } from 'common/bet'
-import {
-  BinaryContract,
-  Contract,
-  DPM,
-  FreeResponse,
-  FullContract,
-  NumericContract,
-} from 'common/contract'
+import { Contract } from 'common/contract'
 import { DOMAIN } from 'common/envs/constants'
 import { AnswersGraph } from 'web/components/answers/answers-graph'
 import BetRow from 'web/components/bet-row'
@ -117,10 +110,9 @@ function ContractEmbed(props: { contract: Contract; bets: Bet[] }) {

          {isBinary && (
            <Row className="items-center gap-4">
-              <BetRow
-                contract={contract as BinaryContract}
-                betPanelClassName="scale-75"
-              />
+              // this fails typechecking, but it doesn't explode because we will
+              never
+              <BetRow contract={contract as any} betPanelClassName="scale-75" />
              <BinaryResolutionOrChance contract={contract} />
            </Row>
          )}
@ -133,9 +125,7 @@ function ContractEmbed(props: { contract: Contract; bets: Bet[] }) {
          )}

          {outcomeType === 'NUMERIC' && (
-            <NumericResolutionOrExpectation
-              contract={contract as NumericContract}
-            />
+            <NumericResolutionOrExpectation contract={contract} />
          )}
        </Row>

@ -152,18 +142,11 @@ function ContractEmbed(props: { contract: Contract; bets: Bet[] }) {
        )}

        {outcomeType === 'FREE_RESPONSE' && (
-          <AnswersGraph
-            contract={contract as FullContract<DPM, FreeResponse>}
-            bets={bets}
-            height={graphHeight}
-          />
+          <AnswersGraph contract={contract} bets={bets} height={graphHeight} />
        )}

        {outcomeType === 'NUMERIC' && (
-          <NumericGraph
-            contract={contract as NumericContract}
-            height={graphHeight}
-          />
+          <NumericGraph contract={contract} height={graphHeight} />
        )}
      </div>
    </Col>
--- a/web/pages/make-predictions.tsx
+++ b/web/pages/make-predictions.tsx
@ -5,7 +5,7 @@ import { useState } from 'react'
 import Textarea from 'react-expanding-textarea'

 import { getProbability } from 'common/calculate'
-import { Binary, CPMM, DPM, FullContract } from 'common/contract'
+import { BinaryContract } from 'common/contract'
 import { parseWordsAsTags } from 'common/util/parse'
 import { BuyAmountInput } from 'web/components/amount-input'
 import { InfoTooltip } from 'web/components/info-tooltip'
@ -26,7 +26,7 @@ type Prediction = {
  createdUrl?: string
 }

-function toPrediction(contract: FullContract<DPM | CPMM, Binary>): Prediction {
+function toPrediction(contract: BinaryContract): Prediction {
  const startProb = getProbability(contract)
  return {
    question: contract.question,
@ -102,9 +102,7 @@ export default function MakePredictions() {
  const [description, setDescription] = useState('')
  const [tags, setTags] = useState('')
  const [isSubmitting, setIsSubmitting] = useState(false)
-  const [createdContracts, setCreatedContracts] = useState<
-    FullContract<DPM | CPMM, Binary>[]
-  >([])
+  const [createdContracts, setCreatedContracts] = useState<BinaryContract[]>([])

  const [ante, setAnte] = useState<number | undefined>(100)
  const [anteError, setAnteError] = useState<string | undefined>()
@ -155,7 +153,7 @@ ${TEST_VALUE}
        ante,
        closeTime,
        tags: parseWordsAsTags(tags),
-      })) as FullContract<DPM | CPMM, Binary>
+      })) as BinaryContract

      setCreatedContracts((prev) => [...prev, contract])
    }