diff --git a/Cargo.toml b/Cargo.toml
index aefed78..fd0598b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,12 +1,12 @@
 # file: Cargo.toml
-# version: 333
+# version: 334
 
 [workspace]
 resolver = "3"
 members = ["crates/ksp-app-config-desk", "crates/ksp-app-solprices-desk", "crates/ksp-app-wallet-desk", "crates/ksp-config-lib", "crates/ksp-core-lib", "crates/ksp-interface-lib", "crates/ksp-logging-lib", "crates/ksp-offchain-transport-lib", "crates/ksp-onchain-transport-lib", "crates/ksp-program-api", "crates/ksp-store-api", "crates/ksp-store-lib", "crates/ksp-store-postgres-lib", "crates/ksp-wallet-lib"]
 
 [workspace.package]
-version = "0.3.2-pre.2.fix.1"
+version = "0.3.2-pre.3"
 edition = "2024"
 license = "MIT"
 repository = "https://git.sasedev.com/Sasedev/khadhroony-solana-project"
diff --git a/crates/ksp-store-lib/src/error.rs b/crates/ksp-store-lib/src/error.rs
new file mode 100644
index 0000000..2a50c05
--- /dev/null
+++ b/crates/ksp-store-lib/src/error.rs
@@ -0,0 +1,13 @@
+// file: crates/ksp-store-lib/src/error.rs
+// version: 1
+
+/// Error code reserved for operations attempted after a Store backend has entered its closed state.
+pub const ERROR_CODE_BACKEND_CLOSED: ksp_store_api::ErrorCode = ksp_store_api::ErrorCode::new("store", "backend_closed");
+/// Error code used when a known Store backend was selected but its Cargo feature is not compiled.
+pub const ERROR_CODE_BACKEND_NOT_COMPILED: ksp_store_api::ErrorCode = ksp_store_api::ErrorCode::new("store", "backend_not_compiled");
+/// Error code used when a compiled Store backend cannot complete its bounded opening lifecycle.
+pub const ERROR_CODE_BACKEND_OPEN_FAILED: ksp_store_api::ErrorCode = ksp_store_api::ErrorCode::new("store", "backend_open_failed");
+/// Error code used when backend-neutral Store settings violate runtime bounds or invariants.
+pub const ERROR_CODE_SETTINGS_INVALID: ksp_store_api::ErrorCode = ksp_store_api::ErrorCode::new("store", "settings_invalid");
+/// Error code used when a Store cannot complete its explicit shutdown inside the configured bound.
+pub const ERROR_CODE_SHUTDOWN_TIMEOUT: ksp_store_api::ErrorCode = ksp_store_api::ErrorCode::new("store", "shutdown_timeout");
diff --git a/crates/ksp-store-lib/src/lib.rs b/crates/ksp-store-lib/src/lib.rs
index bd9660c..1712715 100644
--- a/crates/ksp-store-lib/src/lib.rs
+++ b/crates/ksp-store-lib/src/lib.rs
@@ -1,5 +1,5 @@
 // file: crates/ksp-store-lib/src/lib.rs
-// version: 2
+// version: 3
 
 #![warn(missing_docs)]
 #![deny(unreachable_pub)]
@@ -7,19 +7,170 @@
 
 //! Common backend-neutral Store runtime facade for KSP.
 //!
-//! `0.3.2-pre.002` establishes only the crate and Cargo feature graph. Runtime
-//! settings, backend selection, lifecycle, error mapping and API reexports are
-//! introduced by later prereleases of `0.3.2`.
+//! `0.3.2-pre.003` materializes Config-independent settings, stable backend
+//! identity, bounded validation and the opaque async Store lifecycle contract.
+//! Physical PostgreSQL connection, pool, TLS and migrations remain private
+//! future slices of this release.
 //!
 //! The default `postgres` feature compiles the official PostgreSQL backend as
 //! an optional implementation dependency. No backend implementation type is
 //! part of this crate's public surface.
 
 mod constants;
+mod error;
+mod settings;
+mod store;
 
-/// Crate-owned tracing target reserved for later Store runtime behavior.
+/// Error code reserved for operations attempted after a Store backend is closed.
+pub use self::error::ERROR_CODE_BACKEND_CLOSED;
+/// Error code used when a known Store backend is selected without its compiled feature.
+pub use self::error::ERROR_CODE_BACKEND_NOT_COMPILED;
+/// Error code used when a compiled Store backend cannot complete opening.
+pub use self::error::ERROR_CODE_BACKEND_OPEN_FAILED;
+/// Error code used when Store settings violate backend-neutral bounds or invariants.
+pub use self::error::ERROR_CODE_SETTINGS_INVALID;
+/// Error code used when explicit Store shutdown exceeds its configured deadline.
+pub use self::error::ERROR_CODE_SHUTDOWN_TIMEOUT;
+/// Bounded PostgreSQL bootstrap and migration settings owned by the Store facade.
+pub use self::settings::PostgresBootstrapSettings;
+/// Bounded PostgreSQL connection-pool settings owned by the Store facade.
+pub use self::settings::PostgresPoolSettings;
+/// PostgreSQL settings owned by the Store facade without exposing backend implementation types.
+pub use self::settings::PostgresStoreSettings;
+/// TLS policy accepted by the backend-neutral PostgreSQL settings surface.
+pub use self::settings::PostgresTlsMode;
+/// Backend identity understood independently from compiled Cargo features.
+pub use self::settings::StoreBackendKind;
+/// Backend-specific settings selected through the common Store facade.
+pub use self::settings::StoreBackendSettings;
+/// Complete backend-neutral settings consumed by the common Store runtime facade.
+pub use self::settings::StoreSettings;
+/// Opaque common Store runtime facade with consuming async shutdown.
+pub use self::store::Store;
+/// Error code used when a RAW write collides with divergent content for the same logical identity.
+pub use ksp_store_api::ERROR_CODE_RAW_CONFLICT;
+/// Error code used when a RAW Store model violates one of its backend-agnostic invariants.
+pub use ksp_store_api::ERROR_CODE_RAW_MODEL_INVALID;
+/// Error code used when a KSP-owned RAW persistence payload violates its format or admission contract.
+pub use ksp_store_api::ERROR_CODE_RAW_PAYLOAD_INVALID;
+/// Error code used when acquisition provenance is malformed, unsafe or internally inconsistent.
+pub use ksp_store_api::ERROR_CODE_RAW_PROVENANCE_INVALID;
+/// Error code used when one RAW query or cursor violates backend-agnostic query invariants.
+pub use ksp_store_api::ERROR_CODE_RAW_QUERY_INVALID;
+/// Error code used when a RAW retention transition violates the logical lifecycle contract.
+pub use ksp_store_api::ERROR_CODE_RAW_RETENTION_INVALID;
+/// Common KSP error type used by Store-facing contracts.
+pub use ksp_store_api::Error;
+/// Stable structured code identifying a KSP error category and condition.
+pub use ksp_store_api::ErrorCode;
+/// Structured contextual field attached to a KSP error.
+pub use ksp_store_api::ErrorContext;
+/// Maximum complete RAW account-data length admitted by the Store API.
+pub use ksp_store_api::MAX_RAW_ACCOUNT_DATA_BYTES;
+/// Maximum UTF-8 byte length accepted for one safe logical RAW/provenance code.
+pub use ksp_store_api::MAX_RAW_CODE_BYTES;
+/// Maximum opaque query cursor length admitted by the Store API.
+pub use ksp_store_api::MAX_RAW_PAGE_CURSOR_BYTES;
+/// Maximum KSP-owned canonical RAW payload admitted by the Store API.
+pub use ksp_store_api::MAX_RAW_PAYLOAD_BYTES;
+/// Maximum source-wire payload size recorded as acquisition metadata.
+pub use ksp_store_api::MAX_RAW_SOURCE_PAYLOAD_BYTES;
+/// Maximum supported Unix millisecond timestamp.
+pub use ksp_store_api::MAX_RAW_UNIX_MILLIS;
+/// Canonical Solana account address primitive shared by persistent models.
+pub use ksp_store_api::Pubkey;
+/// Persistable acquisition observation linked to one complete canonical RAW account state.
+pub use ksp_store_api::RawAccountObservation;
+/// Read capability for persisted RAW account-state observations.
+pub use ksp_store_api::RawAccountObservationRead;
+/// Write capability for additional observations of already persisted RAW account states.
+pub use ksp_store_api::RawAccountObservationWrite;
+/// Canonical complete N1 RAW account state independent from acquisition transport.
+pub use ksp_store_api::RawAccountState;
+/// Backend-independent list query for complete canonical RAW account states.
+pub use ksp_store_api::RawAccountStateQuery;
+/// Read capability for complete canonical RAW account states.
+pub use ksp_store_api::RawAccountStateRead;
+/// Durable backend-independent identity of one canonical RAW account state.
+pub use ksp_store_api::RawAccountStateReference;
+/// Write capability for complete canonical RAW account-state acquisitions.
+pub use ksp_store_api::RawAccountStateWrite;
+/// Origin category describing why one acquisition was performed.
+pub use ksp_store_api::RawAcquisitionOrigin;
+/// Safe source-independent acquisition provenance attached to one persisted observation.
+pub use ksp_store_api::RawAcquisitionProvenance;
+/// Combined outcome of one atomic canonical RAW entity plus observation acquisition.
+pub use ksp_store_api::RawAcquisitionWriteOutcome;
+/// Fixed-size digest identifying canonical or source bytes without retaining them.
+pub use ksp_store_api::RawContentHash;
+/// Outcome for one canonical RAW entity in an idempotent persistence operation.
+pub use ksp_store_api::RawEntityWriteOutcome;
+/// Bounded identifier of one KSP-owned source-independent RAW persistence format.
+pub use ksp_store_api::RawFormatId;
+/// Bounded logical network/cluster identifier used in backend-independent Store identities.
+pub use ksp_store_api::RawNetworkId;
+/// Stable deterministic idempotence key for one persisted acquisition observation.
+pub use ksp_store_api::RawObservationKey;
+/// Outcome for one deterministic acquisition observation write.
+pub use ksp_store_api::RawObservationWriteOutcome;
+/// One deterministic page of backend-independent Store results.
+pub use ksp_store_api::RawPage;
+/// Opaque backend-owned cursor returned by one deterministic Store query.
+pub use ksp_store_api::RawPageCursor;
+/// Caller-requested page size without an arbitrary KSP policy ceiling.
+pub use ksp_store_api::RawPageLimit;
+/// Opaque-cursor page request used by backend-independent list operations.
+pub use ksp_store_api::RawPageRequest;
+/// Bounded source-independent KSP RAW persistence payload.
+pub use ksp_store_api::RawPayload;
+/// Bounded logical code used by acquisition provenance fields.
+pub use ksp_store_api::RawProvenanceCode;
+/// Logical availability state of one canonical RAW payload.
+pub use ksp_store_api::RawRetentionState;
+/// Outcome of one atomic RAW retention transition.
+pub use ksp_store_api::RawRetentionWriteOutcome;
+/// Optional inclusive Solana slot bounds for one Store query.
+pub use ksp_store_api::RawSlotRange;
+/// Deterministic traversal direction for Store list queries.
+pub use ksp_store_api::RawSortDirection;
+/// Bounded UTC timestamp represented as whole milliseconds since Unix epoch.
+pub use ksp_store_api::RawTimestamp;
+/// Canonical source-independent N1 RAW transaction persisted by Store backends.
+pub use ksp_store_api::RawTransaction;
+/// Explicit write mode for canonical RAW transaction acquisitions.
+pub use ksp_store_api::RawTransactionAcquisitionMode;
+/// Persistable acquisition observation linked to one canonical RAW transaction.
+pub use ksp_store_api::RawTransactionObservation;
+/// Read capability for persisted RAW transaction observations.
+pub use ksp_store_api::RawTransactionObservationRead;
+/// Write capability for additional observations of already persisted RAW transactions.
+pub use ksp_store_api::RawTransactionObservationWrite;
+/// Backend-independent list query for canonical RAW transactions.
+pub use ksp_store_api::RawTransactionQuery;
+/// Read capability for canonical RAW transactions.
+pub use ksp_store_api::RawTransactionRead;
+/// Durable backend-independent identity of one canonical RAW transaction.
+pub use ksp_store_api::RawTransactionReference;
+/// Read capability for canonical RAW transaction retention metadata.
+pub use ksp_store_api::RawTransactionRetentionRead;
+/// Requested compare-and-transition operation for one RAW transaction retention state.
+pub use ksp_store_api::RawTransactionRetentionTransition;
+/// Write capability for policy-authorized RAW transaction retention transitions.
+pub use ksp_store_api::RawTransactionRetentionWrite;
+/// Canonical 64-byte Solana transaction signature used by Store identities.
+pub use ksp_store_api::RawTransactionSignature;
+/// Minimal durable identity retained after a canonical RAW transaction payload is purged.
+pub use ksp_store_api::RawTransactionTombstone;
+/// Write capability for canonical RAW transaction acquisitions.
+pub use ksp_store_api::RawTransactionWrite;
+/// Common KSP result alias using [`Error`].
+pub use ksp_store_api::Result;
+/// Boxed async operation returned by object-safe Store capability contracts.
+pub use ksp_store_api::StoreApiFuture;
+
+/// Crate-owned tracing target reserved for Store runtime behavior.
 pub(crate) use self::constants::TRACING_TARGET;
 
 // Keep the mandatory crate-owned tracing target part of the compiled scaffold
-// without inventing runtime logging before the first behavioral tranche.
-const _: &str = TRACING_TARGET;
+// without inventing runtime logging before the first behavioral log site.
+const _: &str = crate::TRACING_TARGET;
diff --git a/crates/ksp-store-lib/src/settings.rs b/crates/ksp-store-lib/src/settings.rs
new file mode 100644
index 0000000..50db947
--- /dev/null
+++ b/crates/ksp-store-lib/src/settings.rs
@@ -0,0 +1,381 @@
+// file: crates/ksp-store-lib/src/settings.rs
+// version: 1
+
+const DEFAULT_CONNECT_TIMEOUT_MS: u64 = 10_000;
+const DEFAULT_MAX_CONNECTIONS: u32 = 8;
+const DEFAULT_MIGRATION_LOCK_TIMEOUT_MS: u64 = 10_000;
+const DEFAULT_MIGRATION_TIMEOUT_MS: u64 = 30_000;
+const DEFAULT_POOL_CREATE_TIMEOUT_MS: u64 = 10_000;
+const DEFAULT_POOL_RECYCLE_TIMEOUT_MS: u64 = 5_000;
+const DEFAULT_POOL_WAIT_TIMEOUT_MS: u64 = 5_000;
+const DEFAULT_SHUTDOWN_TIMEOUT_MS: u64 = 5_000;
+const MAX_CONNECTIONS: u32 = 64;
+const MAX_CONNECT_TIMEOUT_MS: u64 = 60_000;
+const MAX_MIGRATION_LOCK_TIMEOUT_MS: u64 = 120_000;
+const MAX_MIGRATION_TIMEOUT_MS: u64 = 300_000;
+const MAX_POOL_CREATE_TIMEOUT_MS: u64 = 60_000;
+const MAX_POOL_RECYCLE_TIMEOUT_MS: u64 = 60_000;
+const MAX_POOL_WAIT_TIMEOUT_MS: u64 = 60_000;
+const MAX_SHUTDOWN_TIMEOUT_MS: u64 = 30_000;
+const MIN_CONNECTIONS: u32 = 1;
+const MIN_CONNECT_TIMEOUT_MS: u64 = 100;
+const MIN_MIGRATION_LOCK_TIMEOUT_MS: u64 = 100;
+const MIN_MIGRATION_TIMEOUT_MS: u64 = 1_000;
+const MIN_POOL_CREATE_TIMEOUT_MS: u64 = 100;
+const MIN_POOL_RECYCLE_TIMEOUT_MS: u64 = 100;
+const MIN_POOL_WAIT_TIMEOUT_MS: u64 = 100;
+const MIN_SHUTDOWN_TIMEOUT_MS: u64 = 100;
+
+/// Backend identity understood by the common Store runtime independently from compiled Cargo features.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[non_exhaustive]
+pub enum StoreBackendKind {
+    /// Official PostgreSQL Store backend.
+    Postgres,
+}
+
+impl StoreBackendKind {
+    /// Returns the stable safe backend code used in diagnostics and configuration mapping.
+    #[must_use]
+    pub const fn code(&self) -> &'static str {
+        return match self {
+            Self::Postgres => "postgres",
+        };
+    }
+}
+
+/// TLS policy accepted by the backend-neutral PostgreSQL settings surface.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[non_exhaustive]
+pub enum PostgresTlsMode {
+    /// Connect without TLS.
+    Disabled,
+    /// Require TLS and verify both the certificate chain and requested server identity.
+    VerifyFull,
+}
+
+/// Bounded PostgreSQL connection-pool settings owned by the Store facade.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct PostgresPoolSettings {
+    connect_timeout: std::time::Duration,
+    create_timeout: std::time::Duration,
+    max_connections: u32,
+    recycle_timeout: std::time::Duration,
+    wait_timeout: std::time::Duration,
+}
+
+impl PostgresPoolSettings {
+    /// Creates explicit PostgreSQL pool bounds without performing any I/O.
+    #[must_use]
+    pub const fn new(
+        max_connections: u32,
+        connect_timeout: std::time::Duration,
+        wait_timeout: std::time::Duration,
+        create_timeout: std::time::Duration,
+        recycle_timeout: std::time::Duration,
+    ) -> Self {
+        return Self { connect_timeout, create_timeout, max_connections, recycle_timeout, wait_timeout };
+    }
+
+    /// Returns the timeout for establishing one physical PostgreSQL connection.
+    #[must_use]
+    pub const fn connect_timeout(&self) -> std::time::Duration {
+        return self.connect_timeout;
+    }
+
+    /// Returns the timeout for creating one pooled PostgreSQL object.
+    #[must_use]
+    pub const fn create_timeout(&self) -> std::time::Duration {
+        return self.create_timeout;
+    }
+
+    /// Returns the maximum number of physical PostgreSQL connections owned by the pool.
+    #[must_use]
+    pub const fn max_connections(&self) -> u32 {
+        return self.max_connections;
+    }
+
+    /// Returns the timeout for recycling one pooled PostgreSQL object.
+    #[must_use]
+    pub const fn recycle_timeout(&self) -> std::time::Duration {
+        return self.recycle_timeout;
+    }
+
+    /// Returns the maximum time one acquisition can wait for pool capacity.
+    #[must_use]
+    pub const fn wait_timeout(&self) -> std::time::Duration {
+        return self.wait_timeout;
+    }
+
+    /// Validates all pool bounds without opening a connection.
+    pub fn validate(&self) -> ksp_store_api::Result<()> {
+        if self.max_connections < MIN_CONNECTIONS || self.max_connections > MAX_CONNECTIONS {
+            return std::result::Result::Err(
+                ksp_store_api::Error::new(crate::ERROR_CODE_SETTINGS_INVALID, "PostgreSQL pool connection bound is invalid")
+                    .with_context("field", "postgres.pool.max_connections")
+                    .with_context("minimum", MIN_CONNECTIONS.to_string())
+                    .with_context("maximum", MAX_CONNECTIONS.to_string()),
+            );
+        }
+        let connect_validation = validate_duration("postgres.pool.connect_timeout", self.connect_timeout, MIN_CONNECT_TIMEOUT_MS, MAX_CONNECT_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = connect_validation {
+            return std::result::Result::Err(error);
+        }
+        let wait_validation = validate_duration("postgres.pool.wait_timeout", self.wait_timeout, MIN_POOL_WAIT_TIMEOUT_MS, MAX_POOL_WAIT_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = wait_validation {
+            return std::result::Result::Err(error);
+        }
+        let create_validation = validate_duration("postgres.pool.create_timeout", self.create_timeout, MIN_POOL_CREATE_TIMEOUT_MS, MAX_POOL_CREATE_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = create_validation {
+            return std::result::Result::Err(error);
+        }
+        let recycle_validation =
+            validate_duration("postgres.pool.recycle_timeout", self.recycle_timeout, MIN_POOL_RECYCLE_TIMEOUT_MS, MAX_POOL_RECYCLE_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = recycle_validation {
+            return std::result::Result::Err(error);
+        }
+        return std::result::Result::Ok(());
+    }
+}
+
+impl std::default::Default for PostgresPoolSettings {
+    fn default() -> Self {
+        return Self::new(
+            DEFAULT_MAX_CONNECTIONS,
+            std::time::Duration::from_millis(DEFAULT_CONNECT_TIMEOUT_MS),
+            std::time::Duration::from_millis(DEFAULT_POOL_WAIT_TIMEOUT_MS),
+            std::time::Duration::from_millis(DEFAULT_POOL_CREATE_TIMEOUT_MS),
+            std::time::Duration::from_millis(DEFAULT_POOL_RECYCLE_TIMEOUT_MS),
+        );
+    }
+}
+
+/// Bounded PostgreSQL bootstrap settings owned by the Store facade.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct PostgresBootstrapSettings {
+    auto_migrate: bool,
+    migration_lock_timeout: std::time::Duration,
+    migration_timeout: std::time::Duration,
+}
+
+impl PostgresBootstrapSettings {
+    /// Creates explicit bootstrap behavior and migration deadlines.
+    #[must_use]
+    pub const fn new(auto_migrate: bool, migration_timeout: std::time::Duration, migration_lock_timeout: std::time::Duration) -> Self {
+        return Self { auto_migrate, migration_lock_timeout, migration_timeout };
+    }
+
+    /// Returns whether pending KSP-owned migrations may be applied during Store opening.
+    #[must_use]
+    pub const fn auto_migrate(&self) -> bool {
+        return self.auto_migrate;
+    }
+
+    /// Returns the bounded wait allowed for the private PostgreSQL migration lock.
+    #[must_use]
+    pub const fn migration_lock_timeout(&self) -> std::time::Duration {
+        return self.migration_lock_timeout;
+    }
+
+    /// Returns the bounded duration allowed for one migration/bootstrap run.
+    #[must_use]
+    pub const fn migration_timeout(&self) -> std::time::Duration {
+        return self.migration_timeout;
+    }
+
+    /// Validates bootstrap and migration deadlines without contacting PostgreSQL.
+    pub fn validate(&self) -> ksp_store_api::Result<()> {
+        let migration_validation =
+            validate_duration("postgres.bootstrap.migration_timeout", self.migration_timeout, MIN_MIGRATION_TIMEOUT_MS, MAX_MIGRATION_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = migration_validation {
+            return std::result::Result::Err(error);
+        }
+        let lock_validation = validate_duration(
+            "postgres.bootstrap.migration_lock_timeout",
+            self.migration_lock_timeout,
+            MIN_MIGRATION_LOCK_TIMEOUT_MS,
+            MAX_MIGRATION_LOCK_TIMEOUT_MS,
+        );
+        if let std::result::Result::Err(error) = lock_validation {
+            return std::result::Result::Err(error);
+        }
+        return std::result::Result::Ok(());
+    }
+}
+
+impl std::default::Default for PostgresBootstrapSettings {
+    fn default() -> Self {
+        return Self::new(
+            true,
+            std::time::Duration::from_millis(DEFAULT_MIGRATION_TIMEOUT_MS),
+            std::time::Duration::from_millis(DEFAULT_MIGRATION_LOCK_TIMEOUT_MS),
+        );
+    }
+}
+
+/// PostgreSQL settings owned by the Store facade and independent from Config or backend implementation types.
+pub struct PostgresStoreSettings {
+    bootstrap: PostgresBootstrapSettings,
+    connection_uri: std::string::String,
+    pool: PostgresPoolSettings,
+    tls_mode: PostgresTlsMode,
+}
+
+impl PostgresStoreSettings {
+    /// Creates PostgreSQL Store settings from an explicitly supplied sensitive connection URI and typed runtime bounds.
+    #[must_use]
+    pub fn new(
+        connection_uri: impl std::convert::Into<std::string::String>,
+        pool: PostgresPoolSettings,
+        tls_mode: PostgresTlsMode,
+        bootstrap: PostgresBootstrapSettings,
+    ) -> Self {
+        return Self { bootstrap, connection_uri: connection_uri.into(), pool, tls_mode };
+    }
+
+    /// Returns the PostgreSQL bootstrap settings without exposing the sensitive connection URI.
+    #[must_use]
+    pub const fn bootstrap(&self) -> PostgresBootstrapSettings {
+        return self.bootstrap;
+    }
+
+    /// Returns the PostgreSQL pool settings without exposing the sensitive connection URI.
+    #[must_use]
+    pub const fn pool(&self) -> PostgresPoolSettings {
+        return self.pool;
+    }
+
+    /// Returns the selected PostgreSQL TLS policy without exposing the sensitive connection URI.
+    #[must_use]
+    pub const fn tls_mode(&self) -> PostgresTlsMode {
+        return self.tls_mode;
+    }
+
+    /// Validates backend-neutral PostgreSQL settings without parsing the URI or performing I/O.
+    pub fn validate(&self) -> ksp_store_api::Result<()> {
+        if self.connection_uri.is_empty() {
+            return std::result::Result::Err(
+                ksp_store_api::Error::new(crate::ERROR_CODE_SETTINGS_INVALID, "PostgreSQL connection URI is required")
+                    .with_context("field", "postgres.connection_uri"),
+            );
+        }
+        let pool_validation = self.pool.validate();
+        if let std::result::Result::Err(error) = pool_validation {
+            return std::result::Result::Err(error);
+        }
+        let bootstrap_validation = self.bootstrap.validate();
+        if let std::result::Result::Err(error) = bootstrap_validation {
+            return std::result::Result::Err(error);
+        }
+        return std::result::Result::Ok(());
+    }
+}
+
+impl std::fmt::Debug for PostgresStoreSettings {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        return formatter
+            .debug_struct("PostgresStoreSettings")
+            .field("connection_uri", &"<redacted>")
+            .field("pool", &self.pool)
+            .field("tls_mode", &self.tls_mode)
+            .field("bootstrap", &self.bootstrap)
+            .finish();
+    }
+}
+
+/// Backend-specific settings selected through the common Store facade.
+#[derive(Debug)]
+#[non_exhaustive]
+pub enum StoreBackendSettings {
+    /// Settings for the known PostgreSQL backend, whether or not its Cargo feature is compiled.
+    Postgres(PostgresStoreSettings),
+}
+
+impl StoreBackendSettings {
+    /// Returns the stable backend identity represented by these settings.
+    #[must_use]
+    pub const fn kind(&self) -> StoreBackendKind {
+        return match self {
+            Self::Postgres(_) => StoreBackendKind::Postgres,
+        };
+    }
+
+    /// Validates backend-specific settings without performing I/O.
+    pub fn validate(&self) -> ksp_store_api::Result<()> {
+        return match self {
+            Self::Postgres(settings) => settings.validate(),
+        };
+    }
+}
+
+/// Complete backend-neutral settings consumed by the common Store runtime facade.
+#[derive(Debug)]
+pub struct StoreSettings {
+    backend: StoreBackendSettings,
+    shutdown_timeout: std::time::Duration,
+}
+
+impl StoreSettings {
+    /// Creates complete Store runtime settings from one explicit backend and shutdown bound.
+    #[must_use]
+    pub const fn new(backend: StoreBackendSettings, shutdown_timeout: std::time::Duration) -> Self {
+        return Self { backend, shutdown_timeout };
+    }
+
+    /// Returns the selected backend settings.
+    #[must_use]
+    pub const fn backend(&self) -> &StoreBackendSettings {
+        return &self.backend;
+    }
+
+    /// Returns the selected stable backend identity.
+    #[must_use]
+    pub const fn backend_kind(&self) -> StoreBackendKind {
+        return self.backend.kind();
+    }
+
+    /// Returns the maximum duration allowed for explicit Store shutdown.
+    #[must_use]
+    pub const fn shutdown_timeout(&self) -> std::time::Duration {
+        return self.shutdown_timeout;
+    }
+
+    /// Validates all backend-neutral Store settings before any backend I/O can start.
+    pub fn validate(&self) -> ksp_store_api::Result<()> {
+        let shutdown_validation = validate_duration("shutdown_timeout", self.shutdown_timeout, MIN_SHUTDOWN_TIMEOUT_MS, MAX_SHUTDOWN_TIMEOUT_MS);
+        if let std::result::Result::Err(error) = shutdown_validation {
+            return std::result::Result::Err(error);
+        }
+        let backend_validation = self.backend.validate();
+        if let std::result::Result::Err(error) = backend_validation {
+            return std::result::Result::Err(error);
+        }
+        return std::result::Result::Ok(());
+    }
+}
+
+impl StoreSettings {
+    /// Creates settings using the common default shutdown bound while keeping backend construction explicit.
+    #[must_use]
+    pub fn with_default_shutdown(backend: StoreBackendSettings) -> Self {
+        return Self::new(backend, std::time::Duration::from_millis(DEFAULT_SHUTDOWN_TIMEOUT_MS));
+    }
+}
+
+fn validate_duration(field: &'static str, value: std::time::Duration, minimum_ms: u64, maximum_ms: u64) -> ksp_store_api::Result<()> {
+    let minimum = std::time::Duration::from_millis(minimum_ms);
+    let maximum = std::time::Duration::from_millis(maximum_ms);
+    if value < minimum || value > maximum {
+        return std::result::Result::Err(
+            ksp_store_api::Error::new(crate::ERROR_CODE_SETTINGS_INVALID, "Store runtime duration is outside the supported resource bound")
+                .with_context("field", field)
+                .with_context("minimum_ms", minimum_ms.to_string())
+                .with_context("maximum_ms", maximum_ms.to_string()),
+        );
+    }
+    return std::result::Result::Ok(());
+}
+
+#[cfg(test)]
+#[path = "../unit_tests/settings.rs"]
+mod tests;
diff --git a/crates/ksp-store-lib/src/store.rs b/crates/ksp-store-lib/src/store.rs
new file mode 100644
index 0000000..652d216
--- /dev/null
+++ b/crates/ksp-store-lib/src/store.rs
@@ -0,0 +1,56 @@
+// file: crates/ksp-store-lib/src/store.rs
+// version: 1
+
+/// Opaque common Store runtime facade.
+///
+/// A successful value is returned only after the selected backend has completed its bounded readiness path. `0.3.2-pre.003` establishes the lifecycle
+/// contract but intentionally has no successful opening path until the PostgreSQL runtime foundation is materialized by later prereleases.
+#[derive(Debug)]
+#[non_exhaustive]
+pub struct Store;
+
+impl Store {
+    /// Validates settings, selects the requested backend and opens a ready Store runtime.
+    ///
+    /// A known backend whose Cargo feature is absent is rejected before any I/O. During `0.3.2-pre.003`, the compiled PostgreSQL path also stops before I/O
+    /// with [`crate::ERROR_CODE_BACKEND_OPEN_FAILED`] because physical connection ownership is introduced in `pre.005`.
+    pub async fn open(settings: crate::StoreSettings) -> ksp_store_api::Result<Self> {
+        let validation = settings.validate();
+        if let std::result::Result::Err(error) = validation {
+            return std::result::Result::Err(error);
+        }
+        let backend_kind = settings.backend_kind();
+        return match backend_kind {
+            crate::StoreBackendKind::Postgres => open_postgres_contract(backend_kind).await,
+        };
+    }
+
+    /// Explicitly closes the Store runtime and consumes its facade handle.
+    ///
+    /// `pre.003` cannot yet produce a successful Store instance, so the physical bounded shutdown path remains reserved for backend composition. The consuming
+    /// async signature is fixed here so no pool or backend handle needs to escape later.
+    pub async fn close(self) -> ksp_store_api::Result<()> {
+        return std::result::Result::Ok(());
+    }
+}
+
+#[cfg(feature = "postgres")]
+async fn open_postgres_contract(backend_kind: crate::StoreBackendKind) -> ksp_store_api::Result<Store> {
+    return std::result::Result::Err(
+        ksp_store_api::Error::new(crate::ERROR_CODE_BACKEND_OPEN_FAILED, "PostgreSQL Store runtime opening is not materialized in this prerelease")
+            .with_context("backend", backend_kind.code())
+            .with_context("stage", "runtime_foundation_pending"),
+    );
+}
+
+#[cfg(not(feature = "postgres"))]
+async fn open_postgres_contract(backend_kind: crate::StoreBackendKind) -> ksp_store_api::Result<Store> {
+    return std::result::Result::Err(
+        ksp_store_api::Error::new(crate::ERROR_CODE_BACKEND_NOT_COMPILED, "Selected Store backend is not compiled")
+            .with_context("backend", backend_kind.code()),
+    );
+}
+
+#[cfg(test)]
+#[path = "../unit_tests/store.rs"]
+mod tests;
diff --git a/crates/ksp-store-lib/tests/dependency_boundary.rs b/crates/ksp-store-lib/tests/dependency_boundary.rs
index ef6326c..cef831e 100644
--- a/crates/ksp-store-lib/tests/dependency_boundary.rs
+++ b/crates/ksp-store-lib/tests/dependency_boundary.rs
@@ -1,11 +1,11 @@
 // file: crates/ksp-store-lib/tests/dependency_boundary.rs
-// version: 2
+// version: 3
 
 #![warn(missing_docs)]
 #![deny(unreachable_pub)]
 #![forbid(unsafe_code)]
 
-//! Cargo-feature and dependency-boundary canaries for the common Store runtime scaffold.
+//! Cargo-feature and dependency-boundary canaries for the common Store runtime facade.
 
 #[test]
 fn pre_002_manifest_owns_default_postgres_feature_and_optional_backend_edge() {
@@ -24,30 +24,27 @@ fn pre_002_manifest_owns_default_postgres_feature_and_optional_backend_edge() {
         "deadpool-postgres",
         "rustls",
     ] {
-        assert!(!manifest.contains(forbidden), "forbidden pre.002 Store facade dependency detected: {forbidden}");
+        assert!(!manifest.contains(forbidden), "forbidden Store facade dependency detected: {forbidden}");
     }
     return;
 }
 
 #[test]
-fn pre_002_scaffold_keeps_backend_types_and_future_runtime_surface_private() {
+fn pre_003_facade_adds_only_backend_neutral_settings_lifecycle_and_api_reexports() {
     let crate_root = include_str!("../src/lib.rs");
-    assert!(crate_root.contains("mod constants;"));
-    assert!(crate_root.contains("pub(crate) use self::constants::TRACING_TARGET;"));
-    assert!(crate_root.contains("const _: &str = TRACING_TARGET;"));
-    for forbidden in [
-        "pub mod ",
-        "pub use ksp_store_postgres_lib",
-        "StoreSettings",
-        "StoreBackendSettings",
-        "PostgresStoreSettings",
-        "pub struct Store",
-        "tokio_postgres",
-        "deadpool_postgres",
-    ] {
-        assert!(!crate_root.contains(forbidden), "forbidden pre.002 Store facade surface detected: {forbidden}");
+    assert!(crate_root.contains("mod error;"));
+    assert!(crate_root.contains("mod settings;"));
+    assert!(crate_root.contains("mod store;"));
+    assert!(crate_root.contains("pub use self::settings::StoreSettings;"));
+    assert!(crate_root.contains("pub use self::store::Store;"));
+    assert!(crate_root.contains("pub use ksp_store_api::RawTransaction;"));
+    assert!(crate_root.contains("const _: &str = crate::TRACING_TARGET;"));
+    for forbidden in ["pub mod ", "pub use ksp_store_postgres_lib", "tokio_postgres", "deadpool_postgres", "rustls::", "Pool", "Client", "Row", "Statement"] {
+        assert!(!crate_root.contains(forbidden), "forbidden physical backend facade surface detected: {forbidden}");
+    }
+    let production = format!("{}\n{}", include_str!("../src/settings.rs"), include_str!("../src/store.rs"));
+    for forbidden in ["ksp_config_lib", "std::env", "dotenv", "PGHOST", "PGPORT", "PGUSER", "PGPASSWORD", ".pgpass", "tokio_postgres", "deadpool_postgres"] {
+        assert!(!production.contains(forbidden), "forbidden Store facade ownership bypass detected: {forbidden}");
     }
-    let constants = include_str!("../src/constants.rs");
-    assert!(constants.contains("pub(crate) const TRACING_TARGET: &str = \"ksp-store-lib\";"));
     return;
 }
diff --git a/crates/ksp-store-lib/tests/feature_mismatch.rs b/crates/ksp-store-lib/tests/feature_mismatch.rs
new file mode 100644
index 0000000..7659488
--- /dev/null
+++ b/crates/ksp-store-lib/tests/feature_mismatch.rs
@@ -0,0 +1,46 @@
+// file: crates/ksp-store-lib/tests/feature_mismatch.rs
+// version: 1
+
+#![warn(missing_docs)]
+#![deny(unreachable_pub)]
+#![forbid(unsafe_code)]
+
+//! Feature-selection canaries for known Store backends.
+
+fn poll_ready<T>(future: impl std::future::Future<Output = T>) -> T {
+    let mut future = std::boxed::Box::pin(future);
+    let waker = std::task::Waker::noop();
+    let mut context = std::task::Context::from_waker(waker);
+    return match std::future::Future::poll(future.as_mut(), &mut context) {
+        std::task::Poll::Ready(value) => value,
+        std::task::Poll::Pending => panic!("pre.003 Store feature-dispatch future unexpectedly became pending before any I/O exists"),
+    };
+}
+
+fn settings() -> ksp_store_lib::StoreSettings {
+    let postgres = ksp_store_lib::PostgresStoreSettings::new(
+        "postgresql://operator-supplied-sensitive-value",
+        ksp_store_lib::PostgresPoolSettings::default(),
+        ksp_store_lib::PostgresTlsMode::Disabled,
+        ksp_store_lib::PostgresBootstrapSettings::default(),
+    );
+    return ksp_store_lib::StoreSettings::with_default_shutdown(ksp_store_lib::StoreBackendSettings::Postgres(postgres));
+}
+
+#[cfg(not(feature = "postgres"))]
+#[test]
+fn pre_003_known_postgres_without_feature_returns_stable_error_before_io() {
+    let result = poll_ready(ksp_store_lib::Store::open(settings()));
+    let error = result.err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(ksp_store_lib::ERROR_CODE_BACKEND_NOT_COMPILED));
+    return;
+}
+
+#[cfg(feature = "postgres")]
+#[test]
+fn pre_003_compiled_postgres_path_refuses_to_fake_readiness_before_pre_005() {
+    let result = poll_ready(ksp_store_lib::Store::open(settings()));
+    let error = result.err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(ksp_store_lib::ERROR_CODE_BACKEND_OPEN_FAILED));
+    return;
+}
diff --git a/crates/ksp-store-lib/tests/public_api.rs b/crates/ksp-store-lib/tests/public_api.rs
new file mode 100644
index 0000000..308bd12
--- /dev/null
+++ b/crates/ksp-store-lib/tests/public_api.rs
@@ -0,0 +1,45 @@
+// file: crates/ksp-store-lib/tests/public_api.rs
+// version: 1
+
+#![warn(missing_docs)]
+#![deny(unreachable_pub)]
+#![forbid(unsafe_code)]
+
+//! Public API canaries for Store settings, lifecycle and Store API reexports.
+
+#[test]
+fn pre_003_settings_and_lifecycle_contract_are_available_from_crate_root() {
+    let postgres = ksp_store_lib::PostgresStoreSettings::new(
+        "postgresql://operator-supplied-sensitive-value",
+        ksp_store_lib::PostgresPoolSettings::default(),
+        ksp_store_lib::PostgresTlsMode::VerifyFull,
+        ksp_store_lib::PostgresBootstrapSettings::default(),
+    );
+    let settings = ksp_store_lib::StoreSettings::with_default_shutdown(ksp_store_lib::StoreBackendSettings::Postgres(postgres));
+    assert_eq!(settings.backend_kind(), ksp_store_lib::StoreBackendKind::Postgres);
+    assert!(settings.validate().is_ok());
+    let _open = ksp_store_lib::Store::open;
+    let _close = ksp_store_lib::Store::close;
+    return;
+}
+
+#[test]
+fn pre_003_common_error_codes_are_stable_and_store_owned() {
+    assert_eq!(ksp_store_lib::ERROR_CODE_SETTINGS_INVALID.domain(), "store");
+    assert_eq!(ksp_store_lib::ERROR_CODE_SETTINGS_INVALID.code(), "settings_invalid");
+    assert_eq!(ksp_store_lib::ERROR_CODE_BACKEND_NOT_COMPILED.code(), "backend_not_compiled");
+    assert_eq!(ksp_store_lib::ERROR_CODE_BACKEND_OPEN_FAILED.code(), "backend_open_failed");
+    assert_eq!(ksp_store_lib::ERROR_CODE_BACKEND_CLOSED.code(), "backend_closed");
+    assert_eq!(ksp_store_lib::ERROR_CODE_SHUTDOWN_TIMEOUT.code(), "shutdown_timeout");
+    return;
+}
+
+#[test]
+fn pre_003_facade_reexports_backend_agnostic_store_api_types() {
+    let _raw_transaction = std::mem::size_of::<std::option::Option<ksp_store_lib::RawTransaction>>();
+    let _raw_account_state = std::mem::size_of::<std::option::Option<ksp_store_lib::RawAccountState>>();
+    let _query = std::mem::size_of::<std::option::Option<ksp_store_lib::RawTransactionQuery>>();
+    let _capability = std::mem::size_of::<std::option::Option<&dyn ksp_store_lib::RawTransactionRead>>();
+    let _result: ksp_store_lib::Result<()> = std::result::Result::Ok(());
+    return;
+}
diff --git a/crates/ksp-store-lib/unit_tests/settings.rs b/crates/ksp-store-lib/unit_tests/settings.rs
new file mode 100644
index 0000000..f55525f
--- /dev/null
+++ b/crates/ksp-store-lib/unit_tests/settings.rs
@@ -0,0 +1,139 @@
+// file: crates/ksp-store-lib/unit_tests/settings.rs
+// version: 1
+
+fn valid_postgres_settings() -> crate::PostgresStoreSettings {
+    return crate::PostgresStoreSettings::new(
+        "postgresql://secret-user:secret-password@db.internal/ksp",
+        crate::PostgresPoolSettings::default(),
+        crate::PostgresTlsMode::VerifyFull,
+        crate::PostgresBootstrapSettings::default(),
+    );
+}
+
+#[test]
+fn defaults_match_the_pre_001_runtime_bounds() {
+    let pool = crate::PostgresPoolSettings::default();
+    assert_eq!(pool.max_connections(), 8);
+    assert_eq!(pool.connect_timeout(), std::time::Duration::from_millis(10_000));
+    assert_eq!(pool.wait_timeout(), std::time::Duration::from_millis(5_000));
+    assert_eq!(pool.create_timeout(), std::time::Duration::from_millis(10_000));
+    assert_eq!(pool.recycle_timeout(), std::time::Duration::from_millis(5_000));
+    let bootstrap = crate::PostgresBootstrapSettings::default();
+    assert!(bootstrap.auto_migrate());
+    assert_eq!(bootstrap.migration_timeout(), std::time::Duration::from_millis(30_000));
+    assert_eq!(bootstrap.migration_lock_timeout(), std::time::Duration::from_millis(10_000));
+    let store = crate::StoreSettings::with_default_shutdown(crate::StoreBackendSettings::Postgres(valid_postgres_settings()));
+    assert_eq!(store.shutdown_timeout(), std::time::Duration::from_millis(5_000));
+    assert_eq!(store.backend_kind(), crate::StoreBackendKind::Postgres);
+    return;
+}
+
+#[test]
+fn exact_runtime_boundaries_validate_and_adjacent_values_are_rejected() {
+    let minimum_pool = crate::PostgresPoolSettings::new(
+        1,
+        std::time::Duration::from_millis(100),
+        std::time::Duration::from_millis(100),
+        std::time::Duration::from_millis(100),
+        std::time::Duration::from_millis(100),
+    );
+    assert!(minimum_pool.validate().is_ok());
+    let maximum_pool = crate::PostgresPoolSettings::new(
+        64,
+        std::time::Duration::from_millis(60_000),
+        std::time::Duration::from_millis(60_000),
+        std::time::Duration::from_millis(60_000),
+        std::time::Duration::from_millis(60_000),
+    );
+    assert!(maximum_pool.validate().is_ok());
+    assert!(
+        crate::PostgresPoolSettings::new(
+            0,
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+        )
+        .validate()
+        .is_err()
+    );
+    assert!(
+        crate::PostgresPoolSettings::new(
+            65,
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+        )
+        .validate()
+        .is_err()
+    );
+    assert!(
+        crate::PostgresPoolSettings::new(
+            1,
+            std::time::Duration::from_millis(99),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+        )
+        .validate()
+        .is_err()
+    );
+    assert!(
+        crate::PostgresPoolSettings::new(
+            1,
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(60_001),
+            std::time::Duration::from_millis(100),
+            std::time::Duration::from_millis(100),
+        )
+        .validate()
+        .is_err()
+    );
+    let minimum_bootstrap = crate::PostgresBootstrapSettings::new(false, std::time::Duration::from_millis(1_000), std::time::Duration::from_millis(100));
+    assert!(minimum_bootstrap.validate().is_ok());
+    let maximum_bootstrap = crate::PostgresBootstrapSettings::new(true, std::time::Duration::from_millis(300_000), std::time::Duration::from_millis(120_000));
+    assert!(maximum_bootstrap.validate().is_ok());
+    assert!(
+        crate::PostgresBootstrapSettings::new(true, std::time::Duration::from_millis(999), std::time::Duration::from_millis(100),)
+            .validate()
+            .is_err()
+    );
+    assert!(
+        crate::PostgresBootstrapSettings::new(true, std::time::Duration::from_millis(1_000), std::time::Duration::from_millis(120_001),)
+            .validate()
+            .is_err()
+    );
+    return;
+}
+
+#[test]
+fn store_shutdown_bound_is_independent_from_backend_and_rejects_outside_values() {
+    let valid = crate::StoreSettings::new(crate::StoreBackendSettings::Postgres(valid_postgres_settings()), std::time::Duration::from_millis(100));
+    assert!(valid.validate().is_ok());
+    let invalid = crate::StoreSettings::new(crate::StoreBackendSettings::Postgres(valid_postgres_settings()), std::time::Duration::from_millis(30_001));
+    let error = invalid.validate().err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(crate::ERROR_CODE_SETTINGS_INVALID));
+    return;
+}
+
+#[test]
+fn connection_uri_is_required_but_never_rendered_by_debug_or_validation_error() {
+    let secret = "postgresql://secret-user:secret-password@db.internal/ksp";
+    let settings = valid_postgres_settings();
+    let debug = format!("{settings:?}");
+    assert!(!debug.contains(secret));
+    assert!(!debug.contains("secret-user"));
+    assert!(!debug.contains("secret-password"));
+    assert!(debug.contains("<redacted>"));
+    let empty = crate::PostgresStoreSettings::new(
+        std::string::String::new(),
+        crate::PostgresPoolSettings::default(),
+        crate::PostgresTlsMode::Disabled,
+        crate::PostgresBootstrapSettings::default(),
+    );
+    let error = empty.validate().err();
+    assert_eq!(error.as_ref().map(|value| value.code()), std::option::Option::Some(crate::ERROR_CODE_SETTINGS_INVALID));
+    assert!(!format!("{:?}", error).contains(secret));
+    return;
+}
diff --git a/crates/ksp-store-lib/unit_tests/store.rs b/crates/ksp-store-lib/unit_tests/store.rs
new file mode 100644
index 0000000..5d743a1
--- /dev/null
+++ b/crates/ksp-store-lib/unit_tests/store.rs
@@ -0,0 +1,55 @@
+// file: crates/ksp-store-lib/unit_tests/store.rs
+// version: 1
+
+fn poll_ready<T>(future: impl std::future::Future<Output = T>) -> T {
+    let mut future = std::boxed::Box::pin(future);
+    let waker = std::task::Waker::noop();
+    let mut context = std::task::Context::from_waker(waker);
+    return match std::future::Future::poll(future.as_mut(), &mut context) {
+        std::task::Poll::Ready(value) => value,
+        std::task::Poll::Pending => panic!("pre.003 Store contract future unexpectedly became pending before any I/O exists"),
+    };
+}
+
+fn valid_store_settings() -> crate::StoreSettings {
+    let postgres = crate::PostgresStoreSettings::new(
+        "postgresql://secret-user:secret-password@db.internal/ksp",
+        crate::PostgresPoolSettings::default(),
+        crate::PostgresTlsMode::VerifyFull,
+        crate::PostgresBootstrapSettings::default(),
+    );
+    return crate::StoreSettings::with_default_shutdown(crate::StoreBackendSettings::Postgres(postgres));
+}
+
+#[test]
+fn invalid_settings_are_rejected_before_backend_dispatch() {
+    let postgres = crate::PostgresStoreSettings::new(
+        std::string::String::new(),
+        crate::PostgresPoolSettings::default(),
+        crate::PostgresTlsMode::Disabled,
+        crate::PostgresBootstrapSettings::default(),
+    );
+    let settings = crate::StoreSettings::with_default_shutdown(crate::StoreBackendSettings::Postgres(postgres));
+    let result = poll_ready(crate::Store::open(settings));
+    let error = result.err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(crate::ERROR_CODE_SETTINGS_INVALID));
+    return;
+}
+
+#[cfg(feature = "postgres")]
+#[test]
+fn compiled_postgres_dispatch_does_not_fake_readiness_before_connection_materialization() {
+    let result = poll_ready(crate::Store::open(valid_store_settings()));
+    let error = result.err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(crate::ERROR_CODE_BACKEND_OPEN_FAILED));
+    return;
+}
+
+#[cfg(not(feature = "postgres"))]
+#[test]
+fn known_postgres_without_feature_is_rejected_before_io() {
+    let result = poll_ready(crate::Store::open(valid_store_settings()));
+    let error = result.err();
+    assert_eq!(error.map(|value| value.code()), std::option::Option::Some(crate::ERROR_CODE_BACKEND_NOT_COMPILED));
+    return;
+}
diff --git a/deltas/0.3.2/pre.003.md b/deltas/0.3.2/pre.003.md
new file mode 100644
index 0000000..8cb9632
--- /dev/null
+++ b/deltas/0.3.2/pre.003.md
@@ -0,0 +1,214 @@
+# Delta `0.3.2-pre.003` — Store settings, backend selection et lifecycle contract
+
+## 1. Base requise
+
+Base exacte :
+
+```text
+0.3.2-pre.002-fix.001
+workspace.package.version = 0.3.2-pre.2.fix.1
+```
+
+Le gate opérateur fourni le 29 août 2026 est entièrement vert et sans warning :
+
+```text
+cargo fmt --all                                         PASS
+audit Rust général / exports / workspace                PASS
+audit Markdown                                           PASS — 186 tables / 126 files
+cargo check --workspace                                  PASS
+cargo clippy --workspace --all-targets                   PASS
+cargo test -p ksp-store-lib                              PASS
+cargo test -p ksp-store-postgres-lib                     PASS
+cargo check -p ksp-store-lib --no-default-features      PASS
+```
+
+Le correctif `pre.002-fix.001` est déjà commité. `pre.003` ne réécrit pas ce delta. Le crate-root `ksp-store-lib` étant réellement modifié dans cette tranche, son ancrage `TRACING_TARGET` adopte désormais la forme canonique `const _: &str = crate::TRACING_TARGET;`. `crates/ksp-store-lib/src/constants.rs` n'est pas modifié et conserve donc son header/version existant.
+
+## 2. Objectif
+
+Matérialiser uniquement le contrat runtime backend-neutral prévu par le plan 023 :
+
+```text
+StoreBackendKind
+StoreBackendSettings
+PostgresStoreSettings
+PostgresPoolSettings
+PostgresBootstrapSettings
+PostgresTlsMode
+StoreSettings
+Store::open(settings).await
+Store::close(self).await
+codes d'erreur Store stables
+réexports ksp-store-api depuis la façade
+```
+
+Aucune connexion, pool physique, TLS connector, migration, Config `std.store` ou SQL n'est introduit.
+
+## 3. Settings et bornes
+
+`PostgresStoreSettings` possède une URI explicitement fournie par le caller. Il n'existe aucun `Default` qui invente une URI ou un backend.
+
+La chaîne URI :
+
+```text
+est possédée par le settings
+est intégralement redacted dans Debug
+n'a aucun getter public
+n'entre dans aucun ErrorContext
+n'est pas parsée avant pre.005
+```
+
+Les settings typés matérialisent les bornes décidées en `pre.001` :
+
+```text
+max_connections          défaut 8       plage 1..64
+connect_timeout_ms       défaut 10_000  plage 100..60_000
+pool_wait_timeout_ms     défaut 5_000   plage 100..60_000
+pool_create_timeout_ms   défaut 10_000  plage 100..60_000
+pool_recycle_timeout_ms  défaut 5_000   plage 100..60_000
+shutdown_timeout_ms      défaut 5_000   plage 100..30_000
+auto_migrate             défaut true
+migration_timeout_ms     défaut 30_000  plage 1_000..300_000
+migration_lock_ms        défaut 10_000  plage 100..120_000
+```
+
+Ces bornes restent des garde-fous de ressources/lifecycle et non une policy worker/job.
+
+## 4. Backend selection et lifecycle
+
+Backend connu :
+
+```text
+StoreBackendKind::Postgres
+```
+
+Le dispatch `Store::open` valide d'abord tous les settings puis :
+
+```text
+feature postgres absente   -> store.backend_not_compiled avant I/O
+feature postgres présente  -> store.backend_open_failed / runtime_foundation_pending avant I/O
+```
+
+Le second résultat est volontairement transitoire : `pre.003` ne fabrique jamais un faux `Store` prêt avant la connexion réelle de `pre.005`. La signature finale `Store::close(self).await` est fixée maintenant, mais aucune ressource physique n'existe encore à fermer.
+
+## 5. Erreurs Store communes
+
+Codes crate-root :
+
+```text
+ERROR_CODE_BACKEND_CLOSED       -> store.backend_closed
+ERROR_CODE_BACKEND_NOT_COMPILED -> store.backend_not_compiled
+ERROR_CODE_BACKEND_OPEN_FAILED  -> store.backend_open_failed
+ERROR_CODE_SETTINGS_INVALID      -> store.settings_invalid
+ERROR_CODE_SHUTDOWN_TIMEOUT      -> store.shutdown_timeout
+```
+
+Aucune erreur externe ou chaîne distante n'est attachée à cette tranche.
+
+## 6. Réexports API
+
+`ksp-store-lib` réexporte explicitement les 60 éléments crate-root de `ksp-store-api` nécessaires à la consommation de la façade.
+
+La façade compte donc à cette tranche :
+
+```text
+60 reexports ksp-store-api
+13 éléments runtime Store propres
+73 exports crate-root au total
+```
+
+Aucun type, handle ou symbole de `ksp-store-postgres-lib` n'est réexporté.
+
+## 7. Fichiers
+
+Modifiés :
+
+```text
+Cargo.toml
+crates/ksp-store-lib/src/lib.rs
+crates/ksp-store-lib/tests/dependency_boundary.rs
+docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md
+docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md
+```
+
+Ajoutés :
+
+```text
+crates/ksp-store-lib/src/error.rs
+crates/ksp-store-lib/src/settings.rs
+crates/ksp-store-lib/src/store.rs
+crates/ksp-store-lib/unit_tests/settings.rs
+crates/ksp-store-lib/unit_tests/store.rs
+crates/ksp-store-lib/tests/feature_mismatch.rs
+crates/ksp-store-lib/tests/public_api.rs
+deltas/0.3.2/pre.003.md
+```
+
+Non modifiés intentionnellement :
+
+```text
+crates/ksp-store-lib/src/constants.rs
+crates/ksp-store-postgres-lib/**
+ksp-store-api/**
+config/**
+CHANGELOG.md
+ROADMAP.md
+```
+
+## 8. Version
+
+La tranche touche le runtime/API Rust ; la version workspace devient :
+
+```text
+0.3.2-pre.3
+```
+
+Identifiant de livraison :
+
+```text
+0.3.2-pre.003
+```
+
+## 9. Validations exécutées pendant la préparation
+
+```text
+python3 scripts/audit_rust_workspace_rules.py    PASS
+```
+
+Les validations Cargo ne sont pas disponibles dans l'environnement de génération et ne sont jamais déclarées PASS.
+
+## 10. Gate opérateur requis
+
+```bash
+cargo fmt --all
+python3 scripts/audit_rust_workspace_rules.py
+python3 scripts/audit_markdown_tables.py README.md RULES.md ROADMAP.md CHANGELOG.md docs prompts crates deltas/0.3.2
+cargo check --workspace
+cargo clippy --workspace --all-targets
+cargo test -p ksp-store-api
+cargo test -p ksp-store-lib
+cargo test -p ksp-store-lib --no-default-features
+cargo test -p ksp-store-postgres-lib
+cargo check -p ksp-store-lib --no-default-features
+cargo tree -p ksp-store-lib --edges normal
+cargo tree -p ksp-store-lib -e features
+cargo tree -p ksp-store-postgres-lib --edges normal
+```
+
+## 11. Hors scope et suite
+
+Toujours absents :
+
+```text
+Config std.store
+tokio-postgres
+Deadpool
+Rustls
+connexion PostgreSQL
+migrations/bootstrap physique
+health/readiness physique
+RawTransaction PostgreSQL
+RawAccountState PostgreSQL
+```
+
+Si le gate est vert, `0.3.2-pre.004` ouvre exclusivement Config `std.store`, son schema/example/registry/adaptor et les impacts de packaging strictement requis.
diff --git a/docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md b/docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md
index ebc7d10..827a6d0 100644
--- a/docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md
+++ b/docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md
@@ -1,5 +1,5 @@
 <!-- file: docs/plans/023-V0_3_2_STORE_POSTGRES_FOUNDATION_PLAN.md -->
-<!-- version: 3 -->
+<!-- version: 4 -->
 
 # Plan `0.3.2` — Store/PostgreSQL runtime foundation
 
@@ -366,7 +366,26 @@ migration_lock_ms       défaut 10_000  plage 100..120_000
 
 Il n'existe pas de `Default` qui invente une URI de production. Config et les callers programmatiques doivent construire explicitement le backend settings.
 
-### 8.3 URI et secrets
+### 8.3 Surface exacte matérialisée en `pre.003`
+
+Les noms publics sont figés comme suit :
+
+```text
+StoreBackendKind::Postgres
+StoreBackendSettings::Postgres(PostgresStoreSettings)
+PostgresTlsMode::{Disabled, VerifyFull}
+PostgresPoolSettings
+PostgresBootstrapSettings
+PostgresStoreSettings
+StoreSettings
+Store
+```
+
+`PostgresPoolSettings::default()` et `PostgresBootstrapSettings::default()` portent exactement les bornes décidées par le gate `pre.001`. `StoreSettings::with_default_shutdown(...)` fournit uniquement la borne commune de shutdown à 5 s. Il n'existe toujours aucun `Default` pour `PostgresStoreSettings` ou `StoreSettings`, afin de ne jamais inventer une URI ou un backend de production.
+
+Les validations `pre.003` restent backend-neutral et sans parsing PostgreSQL : URI non vide, pool 1..64, timeouts pool/connect 100..60 000 ms, migration 1 000..300 000 ms, lock 100..120 000 ms et shutdown 100..30 000 ms. Le parsing/normalisation de l'URI et les options réellement honorées restent propriétaires de `pre.005`.
+
+### 8.4 URI et secrets
 
 La connexion URI est considérée sensible intégralement, même lorsqu'elle ne contient pas de mot de passe visible.
 
@@ -421,16 +440,16 @@ La fermeture consomme le Store, ferme le pool, interdit de nouvelles acquisition
 
 Cette forme limite structurellement le risque de close concurrent avec une opération qui emprunte encore le Store.
 
-### 9.3 Erreurs stables candidates
+### 9.3 Erreurs stables matérialisées
 
-Domaine Store commun :
+Domaine Store commun, figé en `pre.003` :
 
 ```text
-STORE_SETTINGS_INVALID
-STORE_BACKEND_NOT_COMPILED
-STORE_BACKEND_OPEN_FAILED
-STORE_BACKEND_CLOSED
-STORE_SHUTDOWN_TIMEOUT
+ERROR_CODE_BACKEND_CLOSED       -> store.backend_closed
+ERROR_CODE_BACKEND_NOT_COMPILED -> store.backend_not_compiled
+ERROR_CODE_BACKEND_OPEN_FAILED  -> store.backend_open_failed
+ERROR_CODE_SETTINGS_INVALID      -> store.settings_invalid
+ERROR_CODE_SHUTDOWN_TIMEOUT      -> store.shutdown_timeout
 ```
 
 Backend PostgreSQL :
@@ -899,6 +918,23 @@ Les deux crates possèdent déjà leur `src/constants.rs` et leur `TRACING_TARGE
 
 Matérialiser `StoreSettings`, `StoreBackendSettings`, `PostgresStoreSettings`, erreurs stable, façade `Store` sans connexion lourde et réexports API. Tester la feature mismatch.
 
+**Statut : matérialisé par `0.3.2-pre.003`, gate opérateur requis.**
+
+La tranche fixe :
+
+```text
+73 exports crate-root de ksp-store-lib : 60 reexports ksp-store-api + 13 éléments runtime Store
+settings Config-independent sans serde/env
+URI PostgreSQL intégralement redacted et sans getter public
+pool/bootstrap/shutdown bornés selon pre.001
+Store::open(settings).await
+Store::close(self).await
+postgres absent de la build -> store.backend_not_compiled avant I/O
+postgres compilé avant pre.005 -> store.backend_open_failed/runtime_foundation_pending avant I/O
+```
+
+Le dernier comportement est volontairement transitoire : `pre.003` ne retourne jamais un faux `Store` prêt. `pre.005` remplacera uniquement ce stop de staging par la construction physique, puis `pre.007` fermera le shutdown/health end-to-end. Aucun type PostgreSQL physique n'est public.
+
 ### `pre.004` — Config `std.store`
 
 Document/schema/example/registry/adaptor, `.env.example`, provenance/sensitivity/redaction, packaging resources strictement nécessaires. Aucun env dans Store/backend.
@@ -993,8 +1029,6 @@ Aucune question architecturale ne bloque `pre.002`.
 Les détails suivants sont réservés à leur tranche sans rouvrir les décisions du gate :
 
 ```text
-nom exact des structs/methods settings en pre.003
-codes numériques/strings finaux des ErrorCode en pre.003
 mapping exact deadpool timeouts en pre.005
 construction exacte du rustls RootCertStore en pre.005
 DDL précis de ksp_store_schema_migrations en pre.006
diff --git a/docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md b/docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md
index af9a98e..b41e82f 100644
--- a/docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md
+++ b/docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md
@@ -1,5 +1,5 @@
 <!-- file: docs/validation/019-V0_3_2_STORE_POSTGRES_FOUNDATION.md -->
-<!-- version: 3 -->
+<!-- version: 4 -->
 
 # Validation `0.3.2` — Store/PostgreSQL runtime foundation
 
@@ -70,6 +70,8 @@ Le gate opérateur après application de `pre.001`, fourni le 29 août 2026, est
 
 Le gate opérateur de `pre.002`, fourni le 29 août 2026, confirme également les tests ciblés, `--no-default-features` et les `cargo tree`. `cargo check`/Clippy terminent avec succès mais signalent deux warnings par nouvelle crate (`TRACING_TARGET` importé mais inutilisé et constant `dead_code`) ; `pre.002-fix.001` traite cet écart par un canari compile-time privé, tout en conservant les invariants KSP-TRACE-102/103 et sans ajouter de logging runtime.
 
+Le gate opérateur de `pre.002-fix.001`, fourni le 29 août 2026, est entièrement vert et sans warning : audits Rust/Markdown, workspace check/Clippy, tests des deux crates et compilation `ksp-store-lib --no-default-features` passent. Cette base est l'entrée effective de `pre.003`.
+
 ## 3. Frontières Cargo
 
 ### V32-DEP-001 — Façade -> API
@@ -150,13 +152,17 @@ Statut : `TODO gate final`, baseline `v0.3.1` déjà verte.
 
 Critère : `StoreSettings` est constructible sans `ksp-config-lib`, sans env et sans serde requis par la façade.
 
-Statut : `TODO pre.003`.
+Matérialisé par `pre.003` : `StoreSettings`, `StoreBackendSettings`, `PostgresStoreSettings`, pool/bootstrap/TLS typés, sans dépendance Config/serde/env.
+
+Statut : `TODO gate opérateur pre.003`.
 
 ### V32-API-002 — Backend connu non compilé
 
 Critère : `Postgres` reste un backend connu sans feature et `Store::open` échoue avant I/O avec un code stable.
 
-Statut : `TODO pre.003`.
+Matérialisé par `pre.003` : le test `feature_mismatch` appelle réellement `Store::open` sous `--no-default-features` et exige `store.backend_not_compiled`.
+
+Statut : `TODO gate opérateur pre.003 / TODO pre.009 final`.
 
 ### V32-API-003 — Aucun type backend physique public
 
@@ -175,7 +181,9 @@ Statut : `TODO pre.009`.
 
 Critère : un consumer de `ksp-store-lib` accède aux contrats Store API utiles sans dépendre directement de la crate backend.
 
-Statut : `TODO pre.003`.
+`pre.003` réexporte explicitement les 60 symboles crate-root acquis de `ksp-store-api` depuis `ksp-store-lib`, sans glob et sans réexport backend.
+
+Statut : `TODO gate opérateur pre.003 / TODO pre.009 exact exports`.
 
 ### V32-API-005 — Lifecycle
 
@@ -189,7 +197,9 @@ close borné
 Drop best-effort seulement
 ```
 
-Statut : `TODO pre.003/pre.007`.
+`pre.003` fixe les signatures `Store::open(settings).await` et `Store::close(self).await` et garde `Store` opaque/non constructible par un consumer. Aucun succès d'ouverture n'est simulé avant la connexion réelle : le backend compilé s'arrête avec `store.backend_open_failed` et le contexte sûr `runtime_foundation_pending`.
+
+Statut : `TODO gate opérateur pre.003` pour les signatures et le staging ; `TODO pre.007` pour le shutdown physique borné.
 
 ## 5. Config ownership
 
@@ -485,11 +495,15 @@ Statut : `TODO pre.009`.
 
 Cas : zéro, inversion, dépassement bornes pour pool/connect/migration/close.
 
-Statut : `TODO pre.003/pre.005/pre.009`.
+Les bornes backend-neutral décidées en `pre.001` sont matérialisées et couvertes par tests unitaires en `pre.003`. Le parsing PostgreSQL et les timeouts physiques restent à `pre.005`.
+
+Statut : `TODO gate opérateur pre.003 / TODO pre.005 / TODO pre.009`.
 
 ### V32-SEC-004 — Feature mismatch avant I/O
 
-Statut : `TODO pre.003/pre.009`.
+`pre.003` matérialise un canari d'intégration compilé avec et sans `postgres`. Sans feature, `Store::open` retourne le code stable `store.backend_not_compiled` avant tout chemin backend physique.
+
+Statut : `TODO gate opérateur pre.003 / TODO pre.009`.
 
 ### V32-SEC-005 — Server error sanitization
 
@@ -514,6 +528,7 @@ Après création des crates :
 ```bash
 cargo test -p ksp-store-api
 cargo test -p ksp-store-lib
+cargo test -p ksp-store-lib --no-default-features
 cargo test -p ksp-store-postgres-lib
 cargo test -p ksp-config-lib
 cargo check -p ksp-store-lib --no-default-features