diff --git a/contracts/factory/Cargo.toml b/contracts/factory/Cargo.toml
index 7bc80ae..a1253f9 100644
--- a/contracts/factory/Cargo.toml
+++ b/contracts/factory/Cargo.toml
@@ -11,6 +11,7 @@ crate-type = ["cdylib", "rlib"]
 soroban-sdk = { workspace = true }
 drip-governor = { path = "../governor" }
 drip-common = { path = "../common" }
+drip-stream = { path = "../stream" }
 
 [dev-dependencies]
 soroban-sdk = { workspace = true, features = ["testutils"] }
diff --git a/contracts/factory/src/lib.rs b/contracts/factory/src/lib.rs
index 124a7a3..65ed084 100644
--- a/contracts/factory/src/lib.rs
+++ b/contracts/factory/src/lib.rs
@@ -336,6 +336,41 @@ impl DripFactory {
             .get(&DataKey::StreamAddr(stream_id))
     }
 
+    /// Cancel multiple streams in one transaction, all authorized by the
+    /// same `sender`.
+    ///
+    /// Mirrors the bulk-creation ergonomics of [`create_batch_streams`](Self::create_batch_streams)
+    /// on the cancellation side. Each stream address in `stream_addresses`
+    /// is cancelled via a cross-contract call to `DripStream::cancel`,
+    /// reusing the per-stream validation, settlement, and event emission.
+    ///
+    /// Atomicity: Soroban transactions are all-or-nothing at the host
+    /// level. If any cancellation fails (e.g. stream already cancelled,
+    /// sender mismatch), the `?` below propagates that error immediately,
+    /// and every state change already made earlier in this same call is
+    /// rolled back by the host — no partial-batch state is ever left behind.
+    pub fn cancel_batch_streams(
+        env: Env,
+        sender: Address,
+        stream_addresses: Vec<Address>,
+    ) -> Result<(), Error> {
+        sender.require_auth();
+
+        if stream_addresses.is_empty() {
+            return Err(Error::EmptyBatch);
+        }
+        if stream_addresses.len() > MAX_BATCH_SIZE {
+            return Err(Error::BatchTooLarge);
+        }
+
+        for stream_addr in stream_addresses.iter() {
+            let stream_client = drip_stream::DripStreamClient::new(&env, &stream_addr);
+            stream_client.cancel(&sender);
+        }
+
+        Ok(())
+    }
+
     /// Batch-resolve stream IDs to their deployed contract addresses.
     ///
     /// Pairs with `streams_by_sender`/`streams_by_recipient`: a page of IDs
@@ -370,6 +405,12 @@ impl DripFactory {
         query::paginate(&env, all, offset, limit)
     }
 
+    /// Paginated list of stream IDs where `recipient` is the beneficiary.
+    ///
+    /// Returns at most `limit` IDs starting at `offset`. When `offset` exceeds
+    /// the total count an empty vector is returned (no error). `limit` is not
+    /// capped at the contract level — callers should use a reasonable value to
+    /// avoid oversized responses.
     pub fn streams_by_recipient(env: Env, recipient: Address, offset: u32, limit: u32) -> Vec<u64> {
         let all: Vec<u64> = env
             .storage()
diff --git a/contracts/factory/src/tests.rs b/contracts/factory/src/tests.rs
index 95636b1..8c16f11 100644
--- a/contracts/factory/src/tests.rs
+++ b/contracts/factory/src/tests.rs
@@ -217,4 +217,28 @@ fn bump_persistent_extends_ttl_of_persistent_entry() {
         let retrieved: Address = s.env.storage().persistent().get(&key).unwrap();
         assert_eq!(retrieved, dummy);
     });
+}
+
+// ── Issue #204: cancel_batch_streams ─────────────────────────────────────────
+
+#[test]
+fn cancel_batch_rejects_empty_list() {
+    let s = Setup::new();
+    let sender = Address::generate(&s.env);
+    let addresses: soroban_sdk::Vec<Address> = soroban_sdk::Vec::new(&s.env);
+
+    let result = s.client.try_cancel_batch_streams(&sender, &addresses);
+    assert_eq!(result, Err(Ok(Error::EmptyBatch)));
+}
+
+#[test]
+fn cancel_batch_rejects_oversized_list() {
+    let s = Setup::new();
+    let sender = Address::generate(&s.env);
+    let mut addresses: soroban_sdk::Vec<Address> = soroban_sdk::Vec::new(&s.env);
+    for _ in 0..101 {
+        addresses.push_back(Address::generate(&s.env));
+    }
+    let result = s.client.try_cancel_batch_streams(&sender, &addresses);
+    assert_eq!(result, Err(Ok(Error::BatchTooLarge)));
 }
\ No newline at end of file
diff --git a/contracts/oracle/src/lib.rs b/contracts/oracle/src/lib.rs
index 9c90606..c60c540 100644
--- a/contracts/oracle/src/lib.rs
+++ b/contracts/oracle/src/lib.rs
@@ -171,6 +171,17 @@ impl TwapOracle {
 
     // ── Reads ────────────────────────────────────────────────────────────
 
+    /// Reconfigure the oracle parameters. Admin-gated.
+    ///
+    /// When `decimals` or `asset_peg` changes relative to the currently stored
+    /// config, all existing price data (`DataKey::Price`, per-feeder
+    /// `DataKey::Submission` entries, and the `DataKey::Submitters` list) is
+    /// cleared. This prevents stale prices submitted under the old config from
+    /// being silently misinterpreted under the new parameters — the next
+    /// `get_twap_price` call will return `NoPriceAvailable` until a fresh
+    /// `submit_price` is made. Changes to `max_staleness` or `oracle_address`
+    /// alone do not clear price data, as those do not affect price magnitude
+    /// interpretation.
     pub fn configure_oracle(env: Env, caller: Address, config: OracleConfig) -> Result<(), Error> {
         require_role_or_admin(&env, &caller, Role::Admin)?;
 
@@ -179,6 +190,30 @@ impl TwapOracle {
         }
 
         bump_instance(&env);
+
+        // Check if decimals or asset_peg changed relative to existing config.
+        // If so, clear all stored price data to prevent magnitude misinterpretation.
+        let existing: Option<OracleConfig> = env.storage().instance().get(&DataKey::Config);
+        if let Some(old) = existing {
+            if old.decimals != config.decimals || old.asset_peg != config.asset_peg {
+                // Clear the legacy single-value price slot.
+                env.storage().instance().remove(&DataKey::Price);
+
+                // Clear every per-feeder submission and the submitter list itself.
+                let submitters: Vec<Address> = env
+                    .storage()
+                    .instance()
+                    .get(&DataKey::Submitters)
+                    .unwrap_or(Vec::new(&env));
+                for feeder in submitters.iter() {
+                    env.storage()
+                        .instance()
+                        .remove(&DataKey::Submission(feeder));
+                }
+                env.storage().instance().remove(&DataKey::Submitters);
+            }
+        }
+
         env.storage().instance().set(&DataKey::Config, &config);
         events::oracle_configured(&env, &caller, config);
         Ok(())
@@ -1313,4 +1348,103 @@ mod tests {
             .as_contract(&client.address, || env.storage().instance().get_ttl());
         assert!(ttl >= 100_000, "instance TTL after submit_price: {ttl}");
     }
+
+    // ── Issue #206: configure_oracle clears stale price on decimals change ────
+
+    #[test]
+    fn configure_oracle_clears_price_when_decimals_change() {
+        let (env, client, admin) = setup();
+        client.initialize(&admin);
+
+        let oracle_addr = Address::generate(&env);
+        let config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 8,
+            asset_peg: 1,
+            max_staleness: 300,
+        };
+        client.configure_oracle(&admin, &config);
+        client.submit_price(&admin, &50_000_000);
+
+        // Price exists and is fresh
+        let price = client.get_twap_price();
+        assert_eq!(price, 50_000_000);
+
+        // Reconfigure with different decimals
+        let new_config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 6,
+            asset_peg: 1,
+            max_staleness: 300,
+        };
+        client.configure_oracle(&admin, &new_config);
+
+        // After decimals change, old price data should be cleared
+        let result = client.try_get_twap_price();
+        assert_eq!(result, Err(Ok(Error::NoPriceAvailable)));
+    }
+
+    #[test]
+    fn configure_oracle_clears_price_when_asset_peg_changes() {
+        let (env, client, admin) = setup();
+        client.initialize(&admin);
+
+        let oracle_addr = Address::generate(&env);
+        let config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 8,
+            asset_peg: 1,
+            max_staleness: 300,
+        };
+        client.configure_oracle(&admin, &config);
+        client.submit_price(&admin, &50_000_000);
+
+        let price = client.get_twap_price();
+        assert_eq!(price, 50_000_000);
+
+        // Reconfigure with different asset_peg
+        let new_config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 8,
+            asset_peg: 2,
+            max_staleness: 300,
+        };
+        client.configure_oracle(&admin, &new_config);
+
+        // After asset_peg change, old price data should be cleared
+        let result = client.try_get_twap_price();
+        assert_eq!(result, Err(Ok(Error::NoPriceAvailable)));
+    }
+
+    #[test]
+    fn configure_oracle_preserves_price_when_only_staleness_changes() {
+        let (env, client, admin) = setup();
+        client.initialize(&admin);
+
+        let oracle_addr = Address::generate(&env);
+        let config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 8,
+            asset_peg: 1,
+            max_staleness: 300,
+        };
+        client.configure_oracle(&admin, &config);
+        client.submit_price(&admin, &50_000_000);
+
+        let price = client.get_twap_price();
+        assert_eq!(price, 50_000_000);
+
+        // Reconfigure with only max_staleness changed
+        let new_config = OracleConfig {
+            oracle_address: oracle_addr.clone(),
+            decimals: 8,
+            asset_peg: 1,
+            max_staleness: 600,
+        };
+        client.configure_oracle(&admin, &new_config);
+
+        // Price should still be available — only staleness window changed
+        let price_after = client.get_twap_price();
+        assert_eq!(price_after, 50_000_000);
+    }
 }
diff --git a/contracts/stream/src/lib.rs b/contracts/stream/src/lib.rs
index d0c81ed..6500a98 100644
--- a/contracts/stream/src/lib.rs
+++ b/contracts/stream/src/lib.rs
@@ -399,6 +399,73 @@ impl DripStream {
         Ok(())
     }
 
+    /// Sender (or operator) tops up and extends the stream in a single call.
+    ///
+    /// Combines [`top_up`](Self::top_up) and [`extend_duration`](Self::extend_duration)
+    /// into one authorized transaction, reducing round-trips and the risk of a
+    /// sender performing only one half of the pair (which would leave the
+    /// stream either underfunded for the extended duration or with idle funds
+    /// past the original `end_time`).
+    ///
+    /// `amount` is deposited into the stream and `extra_time_seconds` is added
+    /// to `end_time`. Both must be non-zero. Open-ended streams (`end_time == 0`)
+    /// cannot be extended — use `top_up` alone instead.
+    pub fn top_up_and_extend(
+        env: Env,
+        caller: Address,
+        amount: i128,
+        extra_time_seconds: u64,
+    ) -> Result<(), Error> {
+        state::with_guard(&env, |env| {
+            Self::_top_up_and_extend(env, &caller, amount, extra_time_seconds)
+        })
+    }
+
+    fn _top_up_and_extend(
+        env: &Env,
+        caller: &Address,
+        amount: i128,
+        extra_time_seconds: u64,
+    ) -> Result<(), Error> {
+        if amount <= 0 {
+            return Err(Error::InvalidAmount);
+        }
+        if extra_time_seconds == 0 {
+            return Err(Error::InvalidTimeRange);
+        }
+
+        let info = state::load(env);
+        require_sender_or_operator(env, caller, &info.sender)?;
+
+        ttl::bump(env);
+        state::assert_not_cancelled(&info)?;
+
+        if info.end_time == 0 {
+            return Err(Error::InvalidTimeRange);
+        }
+
+        let tk = token::Client::new(env, &info.token);
+        let contract_addr = env.current_contract_address();
+
+        // Transfer funds from sender into the contract
+        tk.transfer(&info.sender, &contract_addr, &amount);
+
+        // Update end_time with overflow check
+        let new_end_time = info
+            .end_time
+            .checked_add(extra_time_seconds)
+            .ok_or(Error::ArithmeticOverflow)?;
+
+        let mut updated = info.clone();
+        updated.end_time = new_end_time;
+        state::save(env, &updated);
+
+        let new_balance = tk.balance(&contract_addr);
+        events::topped_up(env, caller, amount, new_balance);
+
+        Ok(())
+    }
+
     /// Sender reclaims unstreamed tokens (only if clawback was enabled).
     pub fn clawback(env: Env, caller: Address) -> Result<i128, Error> {
         state::with_guard(&env, |env| Self::_clawback(env, &caller))
diff --git a/contracts/stream/src/tests.rs b/contracts/stream/src/tests.rs
index ba5e6f9..9d8ace7 100644
--- a/contracts/stream/src/tests.rs
+++ b/contracts/stream/src/tests.rs
@@ -985,3 +985,69 @@ fn cancelled_flag_is_durable_across_invocations() {
     assert_eq!(s.client.withdrawable(), 0);
     assert_eq!(s.client.streamed_total(), 0);
 }
+
+// ── Issue #205: top_up_and_extend convenience ────────────────────────────────
+
+#[test]
+fn top_up_and_extend_updates_balance_and_end_time() {
+    let s = Setup::new(100, 3_600, false);
+    let before_end = s.client.info().end_time;
+
+    // Mint exact deposit needed: 100 rate × 200s = 20_000
+    let token_admin = token::StellarAssetClient::new(&s.env, &s.token.address);
+    token_admin.mint(&s.sender, &20_000);
+
+    let contract_before = s.token.balance(&s.client.address);
+    s.client.top_up_and_extend(&s.sender, &20_000, &200);
+
+    assert_eq!(s.client.info().end_time, before_end + 200);
+    assert_eq!(s.token.balance(&s.client.address), contract_before + 20_000);
+}
+
+#[test]
+fn top_up_and_extend_rejects_zero_amount() {
+    let s = Setup::new(100, 3_600, false);
+    let result = s.client.try_top_up_and_extend(&s.sender, &0, &100);
+    assert_eq!(result, Err(Ok(Error::InvalidAmount)));
+}
+
+#[test]
+fn top_up_and_extend_rejects_zero_extra_time() {
+    let s = Setup::new(100, 3_600, false);
+    let result = s.client.try_top_up_and_extend(&s.sender, &10_000, &0);
+    assert_eq!(result, Err(Ok(Error::InvalidTimeRange)));
+}
+
+#[test]
+fn top_up_and_extend_rejected_on_cancelled_stream() {
+    let s = Setup::new(100, 3_600, false);
+    s.client.cancel(&s.sender);
+
+    let token_admin = token::StellarAssetClient::new(&s.env, &s.token.address);
+    token_admin.mint(&s.sender, &10_000);
+
+    let result = s.client.try_top_up_and_extend(&s.sender, &10_000, &100);
+    assert!(result.is_err());
+}
+
+#[test]
+fn top_up_and_extend_rejected_for_open_ended_stream() {
+    let env = Env::default();
+    env.mock_all_auths();
+
+    let sender = Address::generate(&env);
+    let recipient = Address::generate(&env);
+    let token_admin = Address::generate(&env);
+    let token_addr = env
+        .register_stellar_asset_contract_v2(token_admin.clone())
+        .address();
+
+    let now: u64 = 1_000_000;
+    let stream_id = env.register_contract(None, DripStream);
+    let client = DripStreamClient::new(&env, &stream_id);
+
+    client.initialize(&sender, &recipient, &token_addr, &100, &now, &0, &false);
+
+    let result = client.try_top_up_and_extend(&sender, &10_000, &100);
+    assert_eq!(result, Err(Ok(Error::InvalidTimeRange)));
+}