Auto mode (devnets)¶

Uncommon capability

Most Cosmos faucets require a fully-written chains.yml even for a local devnet — you have to know the chain ID, bech32 prefix, denom, gas prices, and gRPC endpoint before the faucet will start. Pour's auto mode eliminates all of that: point it at the chain's home directory and it figures everything out from genesis.json.

Auto mode lets pour self-configure from a local chain's genesis file. No manual chains.yml entry is needed — pour reads the genesis, derives the chain ID, bech32 prefix, and native denom, then generates or reloads a faucet mnemonic and starts serving.

Basic usage¶

pour serve --auto --home ~/.simapp

--home must point to the chain's home directory. pour reads <home>/config/genesis.json on startup.

With self-funding¶

pour serve --auto --home ~/.simapp --fund-mnemonic "word word word ..."

When --fund-mnemonic is provided, pour derives the funded account's address and sends tokens to the faucet address before opening the HTTP server. This removes the manual step of pre-funding the faucet wallet.

The env var POUR_FUND_MNEMONIC is equivalent to --fund-mnemonic.

Faucet mnemonic lifecycle¶

On first run, pour generates a random BIP39 mnemonic and writes it to ~/.pour/auto-mnemonic (mode 0600). The derived address is logged — fund it before pour will accept drip requests (unless --fund-mnemonic is set).

On subsequent runs the same mnemonic is reloaded from ~/.pour/auto-mnemonic. Set POUR_MNEMONIC to override and use a different key.

Flag reference¶

These flags are only active when --auto is set.

Flag	Default	Description
`--home`	(required)	Chain home directory. Genesis is read from `<home>/config/genesis.json`.
`--grpc`	`localhost:9090`	gRPC endpoint of the running chain.
`--rpc`	`http://localhost:26657`	Tendermint/CometBFT RPC endpoint (used for hot-reload detection).
`--drip`	`1000000<denom>`	Drip amount per request (e.g. `500000uatom`). Defaults to 1 token at 6 decimal places.
`--fund-mnemonic`	—	Mnemonic of a funded genesis account. When set, pour self-funds on startup.
`POUR_FUND_MNEMONIC`	—	Environment variable equivalent of `--fund-mnemonic`.

LCD / REST-only chains¶

If the chain node exposes only a REST (LCD) endpoint and no gRPC, pass --rest instead of --grpc:

pour serve --auto --home ~/.simapp --grpc "" --rest http://localhost:1317

See Transports for details on gRPC vs REST transport selection.

Hot reload (devnet reset detection)¶

Pour polls the RPC endpoint (--rpc) every 5 seconds for the latest block height. If the height drops below the last observed value (indicating a unsafe-reset-all or equivalent chain reset), pour:

Closes all existing gRPC connections
Reconnects to the chain from height 0
Resumes serving drip requests

This means you can reset a local chain without restarting the faucet process.

Note

Hot reload requires the RPC endpoint to be reachable. It has no effect in production deployments where block height regressions do not occur.

Example: ignite chain serve¶

# Terminal 1
ignite chain serve

# Terminal 2 — in your chain's directory
pour serve --auto --home ~/.mylocalchain/

Example: simd start¶

# Terminal 1
simd start --home ~/.simapp

# Terminal 2 — pass the mnemonic you used when initialising the chain
pour serve --auto --home ~/.simapp --fund-mnemonic "word word word ..."

What gets auto-configured¶

Field	Source
`chain_id`	`genesis.json → chain_id`
`bech32_prefix`	Inferred from the HRP of the first address in `genesis.json → app_state.bank.balances`
`native_denom`	`genesis.json → app_state.staking.params.bond_denom`
`slip44`	Always `118` (standard Cosmos coin type)
`drip.anonymous`	`--drip` flag or `1000000<denom>`
`drip.max_per_address_per_day`	`10 × drip.anonymous`
`batch_window`	`"0s"` (synchronous — recommended for single-node devnets)
`endpoints.grpc`	`--grpc` flag
`endpoints.rest`	`--rest` flag (if set)