Configuration

The SDK is configured through PapiConfig, which can be built programmatically or loaded from environment variables.

Environment Variables

Variable	Description	Required	Default
`PAPI_API_KEY`	Your PAPI API key (`papi_sk_*`)	Yes (managed mode)	—
`PAPI_BASE_URL`	API base URL override	No	`https://api.papi.market`
`PAPI_TIMEOUT`	Request timeout in seconds	No	`30`
`PAPI_MODE`	`managed` or `direct`	No	`managed`

Direct Mode Variables

When using direct mode, you provide exchange credentials locally:

Variable	Description	Exchange
`POLYMARKET_PRIVATE_KEY`	Ethereum wallet private key (0x-prefixed, 66 chars)	Polymarket
`KALSHI_EMAIL`	Kalshi account email	Kalshi
`KALSHI_PASSWORD`	Kalshi account password	Kalshi

The SDK derives Polymarket CLOB API credentials (api_key, secret, passphrase) and wallet address automatically from the private key via EIP-712 authentication.

PapiConfig Builder

Managed Mode

use papi_sdk::PapiConfig;

let config = PapiConfig::managed()
    .api_key("<your-api-key>")
    .base_url("https://api.papi.market")  // optional
    .timeout(30)                                     // optional, seconds
    .build()?;

Direct Mode

use papi_sdk::PapiConfig;

let config = PapiConfig::direct()
    .polymarket_private_key("0x-your-wallet-private-key")
    .kalshi_credentials(
        "your-email",
        "your-password",
    )
    .build()?;

From Environment

Load all configuration from environment variables:

use papi_sdk::PapiConfig;

let config = PapiConfig::from_env()?;

This reads PAPI_MODE to determine the mode, then loads the appropriate variables.

Feature Flags

The SDK supports Cargo feature flags for controlling which exchanges are compiled:

Cargo.toml

[dependencies]
# Both exchanges (default)
papi-sdk = "0.1"

# Only Polymarket
papi-sdk = { version = "0.1", default-features = false, features = ["polymarket"] }

# Only Kalshi
papi-sdk = { version = "0.1", default-features = false, features = ["kalshi"] }

Feature	Description	Default
`polymarket`	Polymarket exchange support	Yes
`kalshi`	Kalshi exchange support	Yes
`managed`	Managed mode (PAPI API proxy)	Yes
`direct`	Direct exchange connections	Yes

Retry Configuration

The SDK retries failed requests with exponential backoff by default:

let config = PapiConfig::managed()
    .api_key_from_env()
    .max_retries(3)           // default: 3
    .retry_delay_ms(1000)     // default: 1000ms
    .build()?;

Retries apply to:

Network errors (connection refused, timeout)
429 (rate limited) responses
5xx server errors

They do not apply to:

4xx client errors (except 429)
Successful responses

Configuration

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