diff --git a/contracts/bridge/src/lib.rs b/contracts/bridge/src/lib.rs
index 92fc28d10..cd5d6c548 100644
--- a/contracts/bridge/src/lib.rs
+++ b/contracts/bridge/src/lib.rs
@@ -224,8 +224,8 @@ mod bridge {
                     chain_name: format!("Chain-{}", chain_id),
                     bridge_contract_address: None,
                     is_active: true,
-                    gas_multiplier: 100,    // 1.0x multiplier
-                    confirmation_blocks: 6, // 6 block confirmations
+                    gas_multiplier: propchain_traits::constants::DEFAULT_GAS_MULTIPLIER,
+                    confirmation_blocks: propchain_traits::constants::DEFAULT_CONFIRMATION_BLOCKS,
                     supported_tokens: Vec::new(),
                 };
                 bridge.chain_info.insert(chain_id, &chain_info);
diff --git a/contracts/oracle/src/lib.rs b/contracts/oracle/src/lib.rs
index d1ef0b4a9..9724eef6c 100644
--- a/contracts/oracle/src/lib.rs
+++ b/contracts/oracle/src/lib.rs
@@ -116,9 +116,9 @@ mod propchain_oracle {
                 location_adjustments: Mapping::default(),
                 market_trends: Mapping::default(),
                 comparable_cache: Mapping::default(),
-                max_price_staleness: 3600, // 1 hour
-                min_sources_required: 2,
-                outlier_threshold: 2, // 2 standard deviations
+                max_price_staleness: propchain_traits::constants::DEFAULT_MAX_PRICE_STALENESS,
+                min_sources_required: propchain_traits::constants::DEFAULT_MIN_SOURCES_REQUIRED,
+                outlier_threshold: propchain_traits::constants::DEFAULT_OUTLIER_THRESHOLD,
                 source_reputations: Mapping::default(),
                 source_stakes: Mapping::default(),
                 pending_requests: Mapping::default(),
diff --git a/contracts/traits/src/constants.rs b/contracts/traits/src/constants.rs
new file mode 100644
index 000000000..21a1d1cd5
--- /dev/null
+++ b/contracts/traits/src/constants.rs
@@ -0,0 +1,86 @@
+/// Centralized configuration constants for PropChain contracts.
+///
+/// All magic numbers are extracted here with documentation explaining
+/// their purpose and valid ranges. Contracts import from this module
+/// instead of using inline literals.
+
+// ── Oracle Constants ─────────────────────────────────────────────────────────
+
+/// Maximum age (in seconds) before a price is considered stale.
+/// Default: 3600 (1 hour).
+pub const DEFAULT_MAX_PRICE_STALENESS: u64 = 3600;
+
+/// Minimum number of oracle sources required for a valid valuation.
+pub const DEFAULT_MIN_SOURCES_REQUIRED: u32 = 2;
+
+/// Number of standard deviations beyond which a price is an outlier.
+pub const DEFAULT_OUTLIER_THRESHOLD: u32 = 2;
+
+/// Initial reputation score assigned to new oracle sources (0-1000 scale).
+pub const ORACLE_INITIAL_REPUTATION: u32 = 500;
+
+/// Maximum reputation score an oracle source can achieve.
+pub const ORACLE_MAX_REPUTATION: u32 = 1000;
+
+/// Minimum reputation required for an oracle source to participate.
+pub const ORACLE_MIN_REPUTATION_THRESHOLD: u32 = 200;
+
+/// Reputation points gained on a successful price submission.
+pub const ORACLE_REPUTATION_GAIN: u32 = 10;
+
+/// Reputation points lost on a failed/inaccurate submission.
+pub const ORACLE_REPUTATION_PENALTY: u32 = 50;
+
+/// Multiplier for coefficient of variance calculations (basis points).
+pub const COEFFICIENT_VARIANCE_MULTIPLIER: u32 = 10_000;
+
+// ── Bridge Constants ─────────────────────────────────────────────────────────
+
+/// Default gas multiplier for bridge operations (100 = 1.0x).
+/// Expressed as percentage: 100 = 100% = 1x, 150 = 150% = 1.5x.
+pub const DEFAULT_GAS_MULTIPLIER: u32 = 100;
+
+/// Default number of block confirmations before a bridge tx is final.
+pub const DEFAULT_CONFIRMATION_BLOCKS: u32 = 6;
+
+/// Base gas cost for a bridge operation (in gas units).
+pub const BRIDGE_BASE_GAS: u64 = 100_000;
+
+// ── IPFS / Metadata Constants ────────────────────────────────────────────────
+
+/// Maximum length for property location strings.
+pub const MAX_LOCATION_LENGTH: u32 = 500;
+
+/// Minimum property size in square meters.
+pub const MIN_PROPERTY_SIZE: u64 = 1;
+
+/// Maximum property size in square meters (1 billion).
+pub const MAX_PROPERTY_SIZE: u64 = 1_000_000_000;
+
+/// Maximum length for legal description text.
+pub const MAX_LEGAL_DESCRIPTION_LENGTH: u32 = 5_000;
+
+/// Minimum valuation amount (in smallest token unit).
+pub const MIN_VALUATION: u128 = 1;
+
+/// Maximum file size for IPFS uploads (100 MB).
+pub const MAX_FILE_SIZE: u64 = 100_000_000;
+
+/// Maximum number of documents per property.
+pub const MAX_DOCUMENTS_PER_PROPERTY: u32 = 100;
+
+/// Maximum total pinned size per property (500 MB).
+pub const MAX_PINNED_SIZE_PER_PROPERTY: u64 = 500_000_000;
+
+// ── Token Constants ──────────────────────────────────────────────────────────
+
+/// Precision scaling factor for token amounts (1e12).
+pub const TOKEN_SCALING_FACTOR: u128 = 1_000_000_000_000;
+
+// ── Analytics Constants ──────────────────────────────────────────────────────
+
+/// Default bull/bear ratio in basis points (50% = 5000 bps).
+pub const DEFAULT_BULL_BEAR_RATIO_BPS: u32 = 5_000;
+
+/// Basis points denominator (100% = 10000 bps).
+pub const BASIS_POINTS_DENOMINATOR: u32 = 10_000;
diff --git a/contracts/traits/src/lib.rs b/contracts/traits/src/lib.rs
index fd13e55b2..c63e7016e 100644
--- a/contracts/traits/src/lib.rs
+++ b/contracts/traits/src/lib.rs
@@ -1,5 +1,6 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
+pub mod constants;
 pub mod errors;
 
 use ink::prelude::string::String;