fast CLI

A command-line tool for the Fast network — manage accounts, send USDC, bridge tokens between EVM chains and Fast, fund via fiat, and pay x402-protected APIs.

Installation

Requires Node.js 18+

pnpm install -g @fastxyz/cli

Or use via pnpm in the repo:

pnpm cli --help

Verify:

fast --version
fast --help

Quick Start

# Create an account
fast account create

# Check balances
fast info balance

# Send the network's default token (fastUSD on mainnet) — Fast → Fast
fast send fast1abc...xyz 10

# Send a specific token explicitly
fast send fast1abc...xyz 10 --token USDC

# Bridge USDC from Arbitrum Sepolia to Fast (--token USDC is required on
# mainnet because the network default — fastUSD — is not on EVM chains)
fast fund usdc crypto 50 --chain arbitrum-sepolia --token USDC

# Or get a unified Fast web-app URL to fund fastUSD (mainnet only)
fast fund fastusd --amount 50

# Pay an x402-protected API
fast pay https://api.example.com/resource

Environment

| Variable | Description | | --------------- | ---------------------------------------------------- | | FAST_PASSWORD | Keystore password (preferred over --password flag) |

AI Agent Skill

Install the skill to let AI agents operate the fast CLI on your behalf:

npx skills add https://github.com/fastxyz/fast-sdk/tree/main/skills

Documentation

Full command reference and workflows: skills/fast/SKILL.md

Global Options

These options work with every command:

| Option | Description | |--------|-------------| | --json | Emit machine-readable JSON output instead of human-readable text | | --network <name> | Override the active network (mainnet, testnet) for this command | | --account <name> | Use a specific named account instead of the default | | --password <pwd> | Provide the keystore password (defaults to FAST_PASSWORD env var, then interactive prompt) | | --non-interactive | Auto-confirm confirmations and fail when required input is missing | | --debug | Enable verbose debug logging to stderr |

Default token

Commands that accept --token (currently fast send and fast fund usdc crypto) default to the active network's defaultToken.symbol when the flag is omitted: fastUSD on mainnet, testUSDC on testnet. Bridge routes additionally require the resolved token to exist on the target chain — on mainnet bridges you must pass --token USDC explicitly because fastUSD does not exist on EVM chains.

To customize the default, register a network with fast network add <name> --config <path> where the JSON config includes a defaultToken field, for example:

{
  "defaultToken": {
    "symbol": "USDC",
    "tokenId": "0x...",
    "decimals": 6
  }
}

If a custom network omits defaultToken, callers must pass --token explicitly; otherwise the command errors with INVALID_USAGE.

Commands

fast account create

Create a new Ed25519 account and store it in the local keystore.

fast account create --name my-account

Options: --name <alias> — Optional human-readable alias for the account.

Prompts for an optional keystore password if --password is not given and FAST_PASSWORD is unset.

fast account import

Import an existing account from a 32-byte hex private key.

fast account import --name my-imported-account --private-key 0x...

Options:

• --name <alias> — Optional human-readable alias for the imported account
• --private-key <hex> — Hex-encoded 32-byte private key
• --key-file <path> — Path to a JSON file containing a privateKey field

If --name is omitted, the CLI auto-generates one. You must provide exactly one of --private-key or --key-file.

fast account list

List all stored accounts with their addresses and default status.

fast account list

fast account export

Export an account's private key (requires password).

fast account export my-account

If no account name is provided, the CLI exports the current default account.

fast account set-default

Set the default account for commands that need a signer.

fast account set-default my-account

fast account delete

Delete an account from the local keystore.

fast account delete my-account

fast send <address> <amount>

Send tokens between Fast and supported EVM chains.

fast send fast1recipient... 10.5 --token USDC

Positional arguments:

• <address> — Recipient address (fast1... for Fast, 0x... for EVM)
• <amount> — Human-readable amount (for example, 10 or 1.5)

Options:

• --from-chain <chain> — Source EVM chain for EVM → Fast transfers
• --to-chain <chain> — Destination EVM chain for Fast → EVM transfers
• --token <token> — Token symbol or token ID. Defaults to the network's defaultToken.symbol (fastUSD on mainnet, testUSDC on testnet). Bridge routes require the resolved token to be available on the target chain; otherwise the command errors with CommandUnsupportedForTokenError.
• --eip-7702 — Use the smart deposit flow for EVM → Fast transfers
• --account <name> — Sender account (defaults to the configured default)

fast info balance

Check balances for the current account or a named account.

# By account name
fast info balance --account my-account

# For a specific token
fast info balance --token USDC

fast info status

Check the current network configuration and whether the Fast RPC is reachable.

fast info status

fast info tx <hash>

Look up a transaction by hash in the local CLI history store.

fast info tx 0xabc123...

fast info history

Show recent locally recorded transaction history.

fast info history --from fast1... --limit 20

Options:

• --from <address> — Filter by sender address
• --to <address> — Filter by recipient address
• --token <token> — Filter by token name or token ID
• --limit <n> — Max number of records to return
• --offset <n> — Number of records to skip

fast info bridge-chains

List EVM chains available for Fast-EVM transfers.

fast info bridge-chains

fast info bridge-tokens

List tokens available for Fast-EVM transfers and the chains they are configured on.

fast info bridge-tokens

fast fund usdc fiat

Get a fiat on-ramp URL for funding a Fast address with USDC. The URL targets ramp.fast.xyz; the deposit lands on Fast as bridged USDC, distinct from the Fast-native fastUSD.

fast fund usdc fiat --network mainnet

Requirements:

• Mainnet only (Ramp does not support testnet).
• Active account or --address <fast1...>.

fast fund usdc crypto <amount>

Bridge USDC from an EVM chain to the Fast network. The deposit lands as bridged USDC on Fast (distinct from fastUSD).

fast fund usdc crypto 10.5 --chain arbitrum-sepolia --token USDC

Positional arguments:

• <amount> — Human-readable amount to bridge (e.g., 10.5).

Options:

• --chain <chain> — Source EVM chain (required).
• --token <token> — Token symbol or token ID. Defaults to the network's defaultToken.symbol. On mainnet that's fastUSD, which is not on EVM chains — pass --token USDC explicitly for the bridge case, or the command errors with CommandUnsupportedForTokenError.
• --eip-7702 — Use the smart deposit flow (gas paid in USDC via paymaster).

fast fund fastusd

Print an app.fast.xyz/send URL that opens the unified Fast web app to fund your account with fastUSD (a Fast-native token, separate from bridged USDC). The web app handles fiat-onramp, crypto-bridge, and wallet-to-wallet funding under the hood; the CLI's job is just to produce the URL.

fast fund fastusd
# → https://app.fast.xyz/send?to=fast1...

fast fund fastusd --amount 25
# → https://app.fast.xyz/send?to=fast1...&amount=25

fast fund fastusd --to fast1someoneelse --amount 10
# → https://app.fast.xyz/send?to=fast1someoneelse&amount=10

Options:

• --to <fast1...> — Recipient Fast address (default: active account).
• --amount <decimal> — Optional amount; if omitted, the web app prompts.

Requirements:

• Mainnet only.

fast authorize request

Generate a one-time HPKE authorization request. The command creates a URL for the wallet user to open, and stores a short-lived key in ~/.fast/handover-pending.json (mode 0600, up to 5 minutes).

fast authorize request [--requester NAME] [--url URL]

Options:

• --requester <name> — Optional label shown to the wallet user to identify who is requesting
• --url <url> — Override the wallet base URL the auth link points to (default: https://app.fast.xyz/authorize). Useful for local dev against a non-production wallet, e.g. --url http://localhost:3000/authorize.

Output (human):

Authorization URL:
  https://app.fast.xyz/authorize?data=eyJ...

Fingerprint:    123456
Expires at:     2026-05-25T12:05:00Z

Show the URL to the wallet user. Once they paste back the handover
code, run:
  fast authorize complete --message '<paste here>'

Output (--json):

{
  "auth_url": "...",
  "request_fingerprint": "123456",
  "request_expires_at": "2026-05-25T12:05:00Z"
}

Security note: ~/.fast/handover-pending.json contains the HPKE one-time private key — not the account seed. An attacker who steals only this file cannot derive the account key; they would also need to intercept the handover code the wallet user pastes back. The file expires within 5 minutes and is deleted after a successful authorize complete.

fast authorize complete

Decrypt a handover code returned by the wallet user and print the account private key to stdout.

fast authorize complete [--message TEXT | --stdin] [--print-account] [--json]

Options:

• --message <text> — Handover code or chat message containing it (bare base64url or quoted)
• --stdin — Read the handover code from stdin (e.g., cat code.txt | fast authorize complete --stdin)
• --print-account — Also print the derived Fast address and public key
• --json — Emit JSON output

If neither --message nor --stdin is provided, the CLI prompts interactively. With --non-interactive, absence of both flags is an error.

Output (human, default):

0x1313131313131313131313131313131313131313131313131313131313131313

Output (human, --print-account):

Private key:     0x1313...
Address:         fast1abc...xyz
Public key:      0xdead...beef

Output (--json):

{ "private_key": "0x1313..." }

After a successful decryption, ~/.fast/handover-pending.json is deleted. On decryption failures, the state file is updated (or deleted after 3 attempts) so the same request may be retried.

fast pay <url>

Pay for an x402-protected HTTP resource. The CLI handles the 402 response, signs and submits payment, and retries the request automatically.

fast pay https://api.example.com/premium

Positional arguments:

• <url> — URL of the x402-protected resource (required)

Options:

• --dry-run — Show payment details without actually paying
• --method <GET|POST|...> — HTTP method (default: GET)
• --header <key:value> — Custom request header (can be repeated)
• --body <data> — Request body (use @filepath to read from a file)
• --network <name> — Network to use for payment

Example with headers and body:

fast pay https://api.example.com/analyze \
  --method POST \
  --header "Content-Type: application/json" \
  --body '{"text": "hello world"}'

fast network list

List all configured networks and show which one is the current default.

fast network list

fast network add <name>

Add a custom network configuration by name.

fast network add my-custom-net --config ./network-config.json

Positional arguments:

• <name> — Unique name for the network

Options:

• --config <path> — Path to a JSON file with the network configuration (required)

Example JSON config (network-config.json):

{
  "url": "https://api.fast.xyz/proxy-rest",
  "networkId": "fast:testnet",
  "chainType": "fast"
}

fast network set-default

Set the default network for all subsequent commands.

fast network set-default testnet

fast network remove

Remove a previously added network configuration.

fast network remove my-custom-net

Configuration Files

The CLI stores data in ~/.fast/:

~/.fast/
  fast.db          # SQLite database (accounts, networks, history, encrypted keys)

Environment Variables

| Variable | Description | |----------|-------------| | FAST_PASSWORD | Default keystore password (avoids interactive prompt) |

Examples

Full workflow: fund, check balance, and send

# 1. Create an account
fast account create --name my-account

# 2. Get a fiat on-ramp URL (delivers USDC to your Fast account)
fast fund usdc fiat --network mainnet --address fast1...

# 2b. Or open the unified Fast web app to fund fastUSD
fast fund fastusd --network mainnet

# 3. Check your balance
fast info balance --account my-account

# 4. Send tokens to someone
fast send fast1recipient... 1.25 --account my-account --token USDC

Pay for an x402-protected API

# Simple GET request
fast pay https://api.example.com/premium

# POST with JSON body
fast pay https://api.example.com/analyze \
  --method POST \
  --header "Authorization: Bearer $API_KEY" \
  --body '{"query": "summarize this text"}'

# Dry run to see payment details first
fast pay https://api.example.com/premium --dry-run

See Also

• Root README for monorepo overview
• @fastxyz/sdk for SDK documentation — the CLI uses this internally for signing and REST API calls
• @fastxyz/allset-sdk for bridging details
• Fast Documentation for protocol-level details