diff --git a/packages/sdk-core/tests/resources/Powerup.test.ts b/packages/sdk-core/tests/resources/Powerup.test.ts
new file mode 100644
index 0000000..57e4711
--- /dev/null
+++ b/packages/sdk-core/tests/resources/Powerup.test.ts
@@ -0,0 +1,181 @@
+import { UInt128, UInt64 } from "@wireio/sdk-core/chain/Integer"
+import { BNPrecision, PowerUpState, Resources } from "@wireio/sdk-core"
+import { PowerUpStateResourceCPU } from "@wireio/sdk-core/resources/powerup/Cpu"
+import { PowerUpStateResourceNET } from "@wireio/sdk-core/resources/powerup/Net"
+import { createSampleUsage } from "../support/resources"
+
+/** Matches `PowerUpStateResource` default block CPU limit (μs). */
+const DEFAULT_BLOCK_CPU_LIMIT = 200_000
+/** Matches `PowerUpStateResource` default block net limit (bytes). */
+const DEFAULT_BLOCK_NET_LIMIT = 1_048_576_000
+/**
+ * Day-window multiplier used by PowerUp `*_per_day` helpers:
+ * `limit * 2 * 60 * 60 * 24`.
+ */
+const POWERUP_DAY_WINDOW = 2 * 60 * 60 * 24
+
+/** Shared PowerUp resource fields for CPU/NET fixtures. */
+function powerUpResourceFields(overrides: Record<string, unknown> = {}) {
+  return {
+    version: 0,
+    weight: "100000000000000",
+    weight_ratio: "10000000000000",
+    assumed_stake_weight: "1",
+    initial_weight_ratio: "100000000000000",
+    target_weight_ratio: "10000000000000",
+    initial_timestamp: "2020-01-01T00:00:00",
+    target_timestamp: "2021-01-01T00:00:00",
+    exponent: "2",
+    decay_secs: 86_400,
+    min_price: "0.0000 SYS",
+    max_price: "1000.0000 SYS",
+    utilization: "0",
+    adjusted_utilization: "0",
+    utilization_timestamp: "2020-01-01T00:00:00",
+    ...overrides
+  }
+}
+
+function createCpuState(overrides: Record<string, unknown> = {}) {
+  return PowerUpStateResourceCPU.from(powerUpResourceFields(overrides))
+}
+
+function createNetState(overrides: Record<string, unknown> = {}) {
+  return PowerUpStateResourceNET.from(powerUpResourceFields(overrides))
+}
+
+function createPowerUpState(
+  overrides: Record<string, unknown> = {}
+): InstanceType<typeof PowerUpState> {
+  return PowerUpState.from({
+    version: 0,
+    net: powerUpResourceFields(),
+    cpu: powerUpResourceFields(),
+    powerup_days: 1,
+    min_powerup_fee: "0.0001 SYS",
+    ...overrides
+  })
+}
+
+/** Mocked `Resources` parent that returns a fixed `powup.state` table row. */
+function createPowerUpResources(state = createPowerUpState()) {
+  const getTableRows = jest.fn(async () => ({
+    rows: [state],
+    more: false
+  }))
+
+  const resources = new Resources({
+    api: {
+      v1: {
+        chain: {
+          get_table_rows: getTableRows
+        }
+      }
+    } as any
+  })
+
+  return { resources, getTableRows, state }
+}
+
+describe("PowerUpStateResourceCPU", () => {
+  test("us_per_day uses the default block CPU limit", () => {
+    expect(createCpuState().us_per_day()).toBe(
+      DEFAULT_BLOCK_CPU_LIMIT * POWERUP_DAY_WINDOW
+    )
+  })
+
+  test("us_per_day honors virtual_block_cpu_limit overrides", () => {
+    expect(
+      createCpuState().us_per_day({
+        virtual_block_cpu_limit: UInt64.from(100_000)
+      })
+    ).toBe(100_000 * POWERUP_DAY_WINDOW)
+  })
+
+  test("ms_per_day and per_day derive from us_per_day", () => {
+    const cpu = createCpuState()
+    expect(cpu.ms_per_day()).toBe(cpu.us_per_day() / 1000)
+    expect(cpu.per_day()).toBe(cpu.us_per_day())
+  })
+
+  test("weight_to_us and us_to_weight round-trip with BNPrecision", () => {
+    const cpu = createCpuState()
+    const sample = UInt128.from(100_000_000)
+    const weight = BNPrecision.toNumber()
+    const us = cpu.weight_to_us(sample, weight)
+    expect(us).toBe(100_000_000)
+    expect(cpu.us_to_weight(sample, us)).toBe(weight)
+  })
+
+  test("frac_by_ms multiplies microseconds by 1000", () => {
+    const cpu = createCpuState()
+    const sample = createSampleUsage()
+    expect(cpu.frac_by_ms(sample, 1)).toBe(cpu.frac_by_us(sample, 1000))
+  })
+
+  test("price_per_us returns a finite non-negative fee", () => {
+    const price = createCpuState().price_per_us(createSampleUsage(), 1000)
+    expect(Number.isFinite(price)).toBe(true)
+    expect(price).toBeGreaterThanOrEqual(0)
+  })
+
+  test("allocated reflects the weight_ratio shift toward PowerUp", () => {
+    // 1 - (1e13 / 1e13 / 100) = 0.99
+    expect(createCpuState().allocated).toBeCloseTo(0.99)
+  })
+
+  test("symbol comes from min_price", () => {
+    expect(createCpuState().symbol.name).toBe("SYS")
+  })
+})
+
+describe("PowerUpStateResourceNET", () => {
+  test("bytes_per_day uses the default block net limit", () => {
+    expect(createNetState().bytes_per_day()).toBe(
+      DEFAULT_BLOCK_NET_LIMIT * POWERUP_DAY_WINDOW
+    )
+  })
+
+  test("kb_per_day and per_day derive from bytes_per_day", () => {
+    const net = createNetState()
+    expect(net.kb_per_day()).toBe(net.bytes_per_day() / 1000)
+    expect(net.per_day()).toBe(net.bytes_per_day())
+  })
+
+  test("weight_to_bytes and bytes_to_weight round-trip with BNPrecision", () => {
+    const net = createNetState()
+    const sample = UInt128.from(100_000_000)
+    const weight = BNPrecision.toNumber()
+    const bytes = net.weight_to_bytes(sample, weight)
+    expect(bytes).toBe(100_000_000)
+    expect(net.bytes_to_weight(sample, bytes)).toBe(weight)
+  })
+
+  test("frac_by_kb multiplies bytes by 1000", () => {
+    const net = createNetState()
+    const sample = createSampleUsage()
+    expect(net.frac_by_kb(sample, 1)).toBe(net.frac_by_bytes(sample, 1000))
+  })
+
+  test("price_per_byte returns a finite non-negative fee", () => {
+    const price = createNetState().price_per_byte(createSampleUsage(), 1000)
+    expect(Number.isFinite(price)).toBe(true)
+    expect(price).toBeGreaterThanOrEqual(0)
+  })
+})
+
+describe("PowerUpAPI", () => {
+  test("get_state reads sysio//powup.state and returns the first row", async () => {
+    const { resources, getTableRows, state } = createPowerUpResources()
+    const result = await resources.v1.powerup.get_state()
+
+    expect(result).toBe(state)
+    expect(result).toBeInstanceOf(PowerUpState)
+    expect(getTableRows).toHaveBeenCalledWith({
+      code: "sysio",
+      scope: "",
+      table: "powup.state",
+      type: PowerUpState
+    })
+  })
+})
diff --git a/packages/sdk-core/tests/resources/Ram.test.ts b/packages/sdk-core/tests/resources/Ram.test.ts
new file mode 100644
index 0000000..191a772
--- /dev/null
+++ b/packages/sdk-core/tests/resources/Ram.test.ts
@@ -0,0 +1,94 @@
+import { Asset } from "@wireio/sdk-core/chain/Asset"
+import { Int64 } from "@wireio/sdk-core/chain/Integer"
+import { Resources, RAMState } from "@wireio/sdk-core"
+
+/** Canonical RAM market row used by `sysio.system` bancor pricing tests. */
+function createRamState(
+  overrides: Record<string, unknown> = {}
+): InstanceType<typeof RAMState> {
+  return RAMState.from({
+    supply: "10000000000.0000 RAMCORE",
+    base: {
+      balance: "10000000000.0000 RAM",
+      weight: "0.50000000000000000"
+    },
+    quote: {
+      balance: "10000.0000 SYS",
+      weight: "0.50000000000000000"
+    },
+    ...overrides
+  })
+}
+
+/** Mocked `Resources` parent that returns a fixed `rammarket` table row. */
+function createRamResources(state = createRamState()) {
+  const getTableRows = jest.fn(async () => ({
+    rows: [state],
+    more: false
+  }))
+
+  const resources = new Resources({
+    api: {
+      v1: {
+        chain: {
+          get_table_rows: getTableRows
+        }
+      }
+    } as any
+  })
+
+  return { resources, getTableRows, state }
+}
+
+describe("RAMState", () => {
+  test("get_input ceil-divides quote * value by (base - value)", () => {
+    const state = createRamState()
+    // ceil((100 * 10) / (1000 - 10)) = ceil(1.0101...) = 2
+    expect(
+      Number(state.get_input(Int64.from(1000), Int64.from(100), Int64.from(10)))
+    ).toBe(2)
+  })
+
+  test("price_per returns a SYS asset for the requested byte count", () => {
+    const price = createRamState().price_per(1024)
+    expect(price).toBeInstanceOf(Asset)
+    expect(price.symbol.name).toBe("SYS")
+    expect(price.units.value.gtn(0)).toBe(true)
+  })
+
+  test("price_per_kb prices one kilobyte as 1000 bytes", () => {
+    const state = createRamState()
+    expect(state.price_per_kb(1).equals(state.price_per(1000))).toBe(true)
+  })
+
+  test("price_per scales up for larger byte requests on a shallow market", () => {
+    const state = createRamState({
+      base: {
+        balance: "100000.0000 RAM",
+        weight: "0.50000000000000000"
+      },
+      quote: {
+        balance: "10000.0000 SYS",
+        weight: "0.50000000000000000"
+      }
+    })
+    expect(
+      state.price_per(20_000).units.value.gt(state.price_per(1_000).units.value)
+    ).toBe(true)
+  })
+})
+
+describe("RAMAPI", () => {
+  test("get_state reads sysio/sysio/rammarket and returns the first row", async () => {
+    const { resources, getTableRows, state } = createRamResources()
+    const result = await resources.v1.ram.get_state()
+
+    expect(result).toBe(state)
+    expect(getTableRows).toHaveBeenCalledWith({
+      code: "sysio",
+      scope: "sysio",
+      table: "rammarket",
+      type: RAMState
+    })
+  })
+})
diff --git a/packages/sdk-core/tests/resources/Resources.test.ts b/packages/sdk-core/tests/resources/Resources.test.ts
new file mode 100644
index 0000000..79d6700
--- /dev/null
+++ b/packages/sdk-core/tests/resources/Resources.test.ts
@@ -0,0 +1,93 @@
+import { UInt128 } from "@wireio/sdk-core/chain/Integer"
+import { BNPrecision, Resources } from "@wireio/sdk-core"
+import BN from "bn.js"
+
+/** Account shape required by `Resources.getSampledUsage`. */
+function createAccountObject(overrides: Record<string, unknown> = {}) {
+  return {
+    cpu_limit: { max: UInt128.from(200_000) },
+    net_limit: { max: UInt128.from(1_048_576) },
+    cpu_weight: UInt128.from(10_000),
+    net_weight: UInt128.from(20_000),
+    ...overrides
+  }
+}
+
+describe("Resources", () => {
+  test("throws when neither url nor api is provided", () => {
+    expect(() => new Resources({} as any)).toThrow("Missing url or api client")
+  })
+
+  test("accepts an injected api client and default sample settings", () => {
+    const api = { v1: { chain: {} } } as any
+    const resources = new Resources({ api })
+
+    expect(resources.api).toBe(api)
+    expect(resources.sampleAccount).toBe("greymassfuel")
+    expect(resources.symbol).toBe("4,SYS")
+    expect(resources.v1.ram).toBeDefined()
+    expect(resources.v1.rex).toBeDefined()
+    expect(resources.v1.powerup).toBeDefined()
+  })
+
+  test("honors sampleAccount and symbol overrides", () => {
+    const resources = new Resources({
+      api: { v1: { chain: {} } } as any,
+      sampleAccount: "fuel.sample",
+      symbol: "4,WIRE"
+    })
+
+    expect(resources.sampleAccount).toBe("fuel.sample")
+    expect(resources.symbol).toBe("4,WIRE")
+  })
+
+  test("BNPrecision is 1e8", () => {
+    expect(BNPrecision.eq(new BN(100_000_000))).toBe(true)
+  })
+
+  test("getSampledUsage samples the configured account and ceil-divides weights", async () => {
+    const account = createAccountObject()
+    const getAccount = jest.fn(async () => account)
+    const resources = new Resources({
+      api: {
+        v1: {
+          chain: {
+            get_account: getAccount
+          }
+        }
+      } as any,
+      sampleAccount: "fuel.sample"
+    })
+
+    const sample = await resources.getSampledUsage()
+
+    expect(getAccount).toHaveBeenCalledWith("fuel.sample")
+    expect(sample.account).toBe(account)
+    expect(sample.cpu).toBeInstanceOf(UInt128)
+    expect(sample.net).toBeInstanceOf(UInt128)
+
+    // Mirror Resources.divCeil: (limit * BNPrecision) / weight, then
+    // subtract one when there is a remainder and the quotient is > 1.
+    const expectedCpu = divCeilSample(
+      account.cpu_limit.max.value,
+      account.cpu_weight.value
+    )
+    const expectedNet = divCeilSample(
+      account.net_limit.max.value,
+      account.net_weight.value
+    )
+
+    expect(Number(sample.cpu)).toBe(Number(expectedCpu))
+    expect(Number(sample.net)).toBe(Number(expectedNet))
+  })
+})
+
+/** Local copy of `Resources` sampling math for assertion expected values. */
+function divCeilSample(limit: BN, weight: BN): BN {
+  const num = limit.mul(BNPrecision)
+  let quotient = num.div(weight)
+  if (num.mod(weight).gtn(0) && quotient.gtn(1)) {
+    quotient = quotient.subn(1)
+  }
+  return quotient
+}
diff --git a/packages/sdk-core/tests/resources/Rex.test.ts b/packages/sdk-core/tests/resources/Rex.test.ts
new file mode 100644
index 0000000..4d887fe
--- /dev/null
+++ b/packages/sdk-core/tests/resources/Rex.test.ts
@@ -0,0 +1,92 @@
+import { Asset } from "@wireio/sdk-core/chain/Asset"
+import { Resources, REXState } from "@wireio/sdk-core"
+import { createSampleUsage } from "../support/resources"
+
+/** Canonical REX pool row for pricing and exchange helpers. */
+function createRexState(
+  overrides: Record<string, unknown> = {}
+): InstanceType<typeof REXState> {
+  return REXState.from({
+    version: 0,
+    total_lent: "1000.0000 SYS",
+    total_unlent: "9000.0000 SYS",
+    total_rent: "100.0000 SYS",
+    total_lendable: "10000.0000 SYS",
+    total_rex: "10000.0000 REX",
+    namebid_proceeds: "0.0000 SYS",
+    loan_num: 1,
+    ...overrides
+  })
+}
+
+/** Mocked `Resources` parent that returns a fixed `rexpool` table row. */
+function createRexResources(state = createRexState()) {
+  const getTableRows = jest.fn(async () => ({
+    rows: [state],
+    more: false
+  }))
+
+  const resources = new Resources({
+    api: {
+      v1: {
+        chain: {
+          get_table_rows: getTableRows
+        }
+      }
+    } as any
+  })
+
+  return { resources, getTableRows, state }
+}
+
+describe("REXState", () => {
+  test("reserved is the lent / lendable ratio", () => {
+    expect(createRexState().reserved).toBe(0.1)
+  })
+
+  test("symbol and precision come from total_lent", () => {
+    const state = createRexState()
+    expect(state.symbol.name).toBe("SYS")
+    expect(state.precision).toBe(4)
+  })
+
+  test("value is (lent + unlent) / total_rex in units", () => {
+    // (10000000 + 90000000) / 100000000 = 1
+    expect(createRexState().value).toBe(1)
+  })
+
+  test("exchange converts REX into system tokens at the pool rate", () => {
+    const exchanged = createRexState().exchange(Asset.from("1.0000 REX"))
+    expect(exchanged.toString()).toBe("1.0000 SYS")
+  })
+
+  test("price_per returns a positive SYS fee for sampled CPU", () => {
+    const price = createRexState().price_per(createSampleUsage(), 1000)
+    expect(typeof price).toBe("number")
+    expect(price).toBeGreaterThan(0)
+  })
+
+  test("price_per scales linearly with the requested unit count", () => {
+    const state = createRexState()
+    const sample = createSampleUsage()
+    expect(state.price_per(sample, 2000)).toBeCloseTo(
+      state.price_per(sample, 1000) * 2,
+      8
+    )
+  })
+})
+
+describe("REXAPI", () => {
+  test("get_state reads sysio/sysio/rexpool and returns the first row", async () => {
+    const { resources, getTableRows, state } = createRexResources()
+    const result = await resources.v1.rex.get_state()
+
+    expect(result).toBe(state)
+    expect(getTableRows).toHaveBeenCalledWith({
+      code: "sysio",
+      scope: "sysio",
+      table: "rexpool",
+      type: REXState
+    })
+  })
+})
diff --git a/packages/sdk-core/tests/support/resources.ts b/packages/sdk-core/tests/support/resources.ts
new file mode 100644
index 0000000..4bc596e
--- /dev/null
+++ b/packages/sdk-core/tests/support/resources.ts
@@ -0,0 +1,14 @@
+import { UInt128 } from "@wireio/sdk-core/chain/Integer"
+import { SampleUsage } from "@wireio/sdk-core"
+
+/** Minimal sampled usage used by REX / PowerUp pricing helpers. */
+export function createSampleUsage(
+  overrides: Partial<SampleUsage> = {}
+): SampleUsage {
+  return {
+    account: {} as SampleUsage["account"],
+    cpu: UInt128.from(100_000_000),
+    net: UInt128.from(100_000_000),
+    ...overrides
+  }
+}