diff --git a/apps/policy-engine/src/engine/core/service/signing.service.ts b/apps/policy-engine/src/engine/core/service/signing.service.ts
deleted file mode 100644
index 91e354463..000000000
--- a/apps/policy-engine/src/engine/core/service/signing.service.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import { Payload, PrivateKey, SigningAlg, buildSignerEip191, buildSignerEs256k, signJwt } from '@narval/signature'
-import { Injectable } from '@nestjs/common'
-type SignOptions = {
-  alg?: SigningAlg
-}
-
-@Injectable()
-export class SigningService {
-  constructor() {}
-
-  async sign(payload: Payload, jwk: PrivateKey, opts: SignOptions = {}): Promise<string> {
-    const alg: SigningAlg = opts.alg || jwk.alg
-    if (alg === SigningAlg.ES256K) {
-      const pk = jwk.d
-      const jwt = await signJwt(payload, jwk, opts, buildSignerEs256k(pk))
-
-      return jwt
-    } else if (alg === SigningAlg.EIP191) {
-      const pk = jwk.d
-
-      const jwt = await signJwt(payload, jwk, opts, buildSignerEip191(pk))
-
-      return jwt
-    }
-
-    throw new Error('Unsupported algorithm')
-  }
-}
diff --git a/apps/policy-engine/src/open-policy-agent/core/open-policy-agent.engine.ts b/apps/policy-engine/src/open-policy-agent/core/open-policy-agent.engine.ts
index 89c1d7fa9..c73d1f8ec 100644
--- a/apps/policy-engine/src/open-policy-agent/core/open-policy-agent.engine.ts
+++ b/apps/policy-engine/src/open-policy-agent/core/open-policy-agent.engine.ts
@@ -18,8 +18,6 @@ import {
   PrivateKey,
   PublicKey,
   SigningAlg,
-  base64UrlToHex,
-  buildSignerEip191,
   decode,
   hash,
   privateKeyToJwk,
@@ -320,6 +318,6 @@ export class OpenPolicyAgentEngine implements Engine<OpenPolicyAgentEngine> {
       })
     }
 
-    return signJwt(payload, engineJwk, { alg: SigningAlg.EIP191 }, buildSignerEip191(base64UrlToHex(engineJwk.d)))
+    return signJwt(payload, engineJwk, { alg: SigningAlg.EIP191 })
   }
 }
diff --git a/apps/policy-engine/src/shared/testing/evaluation.testing.ts b/apps/policy-engine/src/shared/testing/evaluation.testing.ts
index 861268e2f..c7774cb43 100644
--- a/apps/policy-engine/src/shared/testing/evaluation.testing.ts
+++ b/apps/policy-engine/src/shared/testing/evaluation.testing.ts
@@ -28,9 +28,9 @@ export const generateInboundEvaluationRequest = async (): Promise<EvaluationRequ
     requestHash: message
   }
 
-  const aliceSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Alice, Alg.ES256K), {})
-  const bobSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Bob, Alg.ES256K), {})
-  const carolSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Carol, Alg.ES256K), {})
+  const aliceSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Alice, Alg.ES256K))
+  const bobSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Bob, Alg.ES256K))
+  const carolSignature = await signJwt(payload, privateKeyToJwk(UNSAFE_PRIVATE_KEY.Carol, Alg.ES256K))
 
   return {
     authentication: aliceSignature,
diff --git a/packages/signature/src/index.ts b/packages/signature/src/index.ts
index bc5640ef4..9bf44efef 100644
--- a/packages/signature/src/index.ts
+++ b/packages/signature/src/index.ts
@@ -4,5 +4,5 @@ export * from './lib/hash-request'
 export * from './lib/schemas'
 export * from './lib/sign'
 export * from './lib/types'
-export * from './lib/utils'
+export { generateJwk, privateKeyToHex, privateKeyToJwk, publicKeyToHex, publicKeyToJwk } from './lib/utils'
 export * from './lib/verify'
diff --git a/packages/signature/src/lib/__test__/unit/sign.spec.ts b/packages/signature/src/lib/__test__/unit/sign.spec.ts
index 4b6725c35..da0cc10f4 100644
--- a/packages/signature/src/lib/__test__/unit/sign.spec.ts
+++ b/packages/signature/src/lib/__test__/unit/sign.spec.ts
@@ -2,16 +2,18 @@ import { secp256k1 } from '@noble/curves/secp256k1'
 import { sha256 as sha256Hash } from '@noble/hashes/sha256'
 import { exportJWK, importPKCS8 } from 'jose'
 import { createPublicKey } from 'node:crypto'
-import { toHex, verifyMessage } from 'viem'
+import { signatureToHex, toHex, verifyMessage } from 'viem'
 import { privateKeyToAccount, signMessage } from 'viem/accounts'
-import { buildSignerEip191, buildSignerEs256k, signJwt } from '../../sign'
-import { Alg, Curves, Jwk, KeyTypes, Payload, SigningAlg } from '../../types'
+import { buildSignerEip191, buildSignerEs256k, signJwt, signSecp256k1 } from '../../sign'
+import { Alg, Curves, Jwk, KeyTypes, Payload, PrivateKey, SigningAlg } from '../../types'
 import {
   base64UrlToBytes,
   base64UrlToHex,
-  ellicpticPublicKeyToHex,
   ellipticPrivateKeyToHex,
-  ellipticPrivateKeyToJwk,
+  ellipticPublicKeyToHex,
+  hexToBase64Url,
+  privateKeyToHex,
+  secp256k1PrivateKeyToJwk,
   secp256k1PublicKeyToJwk
 } from '../../utils'
 import { verifyJwt } from '../../verify'
@@ -56,7 +58,7 @@ describe('sign', () => {
   })
 
   it('should build & sign a EIP191 JWT', async () => {
-    const jwk = ellipticPrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const jwk = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
     const signer = buildSignerEip191(UNSAFE_PRIVATE_KEY)
 
     const jwt = await signJwt(payload, jwk, { alg: SigningAlg.EIP191 }, signer)
@@ -157,7 +159,7 @@ describe('sign', () => {
     const viemPubKey = privateKeyToAccount(`0x${UNSAFE_PRIVATE_KEY}`).publicKey
     expect(toHex(publicKey)).toBe(viemPubKey) // Confirm that our key is in fact the same as what viem would give.
 
-    const jwk = ellipticPrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const jwk = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
 
     const k = await createPublicKey({
       format: 'jwk',
@@ -168,7 +170,7 @@ describe('sign', () => {
   })
 
   it('should convert to and from jwk', async () => {
-    const jwk = ellipticPrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const jwk = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
     const pk = ellipticPrivateKeyToHex(jwk)
     expect(pk).toBe(`0x${UNSAFE_PRIVATE_KEY}`)
   })
@@ -176,7 +178,60 @@ describe('sign', () => {
   it('should convert to and from public jwk', async () => {
     const publicKey = secp256k1.getPublicKey(UNSAFE_PRIVATE_KEY, false)
     const jwk = secp256k1PublicKeyToJwk(toHex(publicKey))
-    const pk = ellicpticPublicKeyToHex(jwk)
+    const pk = ellipticPublicKeyToHex(jwk)
     expect(pk).toBe(toHex(publicKey))
   })
+
+  it('should sign using a custom signer and a key without material', async () => {
+    const privateKey = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const mapOfKeys = new Map<string, PrivateKey>().set(privateKey.kid, privateKey)
+
+    function createSignerWithKid(kid: string): (message: string) => Promise<string> {
+      return async (message: string) => {
+        const privateKeyMaterial = mapOfKeys.get(kid)
+        if (!privateKeyMaterial) {
+          throw new Error(`Key material for kid ${kid} not found.`)
+        }
+        const hash = sha256Hash(message)
+        const key = privateKeyToHex(privateKeyMaterial)
+
+        const signature = signSecp256k1(hash, key)
+        const hexSignature = signatureToHex(signature)
+        return hexToBase64Url(hexSignature)
+      }
+    }
+    // Custom function that mimic a custom signer that would fetch the key material from the kid
+
+    const signer = createSignerWithKid(privateKey.kid)
+    // It would need to have kid context before being passed to signing
+    // TODO: maybe signer should take both the message and the key
+
+    const jwt = await signJwt(payload, privateKey, { alg: SigningAlg.ES256K }, signer)
+    const verified = await verifyJwt(jwt, privateKey)
+    expect(verified.payload).toEqual(payload)
+  })
+
+  it('should sign with default signer and specified algorithm', async () => {
+    const privateKey = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const jwt = await signJwt(payload, privateKey, { alg: SigningAlg.EIP191 })
+    const verified = await verifyJwt(jwt, privateKey)
+    expect(verified.payload).toEqual(payload)
+  })
+
+  it('should sign with default signer and no options provided', async () => {
+    const privateKey = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    const jwt = await signJwt(payload, privateKey)
+    const verified = await verifyJwt(jwt, privateKey)
+    expect(verified.payload).toEqual(payload)
+  })
+
+  it('throws if specified algorithm is not supported by the key', async () => {
+    const privateKey = secp256k1PrivateKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    await expect(signJwt(payload, privateKey, { alg: SigningAlg.ES256 })).rejects.toThrow()
+  })
+
+  it('throws if no signer is provided and key material is not present', async () => {
+    const publicKey = secp256k1PublicKeyToJwk(`0x${UNSAFE_PRIVATE_KEY}`)
+    await expect(signJwt(payload, publicKey)).rejects.toThrow()
+  })
 })
diff --git a/packages/signature/src/lib/__test__/unit/verify.spec.ts b/packages/signature/src/lib/__test__/unit/verify.spec.ts
index c18fcf388..f09e5c18e 100644
--- a/packages/signature/src/lib/__test__/unit/verify.spec.ts
+++ b/packages/signature/src/lib/__test__/unit/verify.spec.ts
@@ -3,7 +3,7 @@ import { hash } from '../../hash-request'
 import { secp256k1PublicKeySchema } from '../../schemas'
 import { signSecp256k1 } from '../../sign'
 import { Alg, Payload, Secp256k1PublicKey } from '../../types'
-import { ellipticPrivateKeyToJwk, privateKeyToJwk } from '../../utils'
+import { privateKeyToJwk, secp256k1PrivateKeyToJwk } from '../../utils'
 import { validate } from '../../validate'
 import { verifyJwt, verifySepc256k1 } from '../../verify'
 
@@ -11,7 +11,7 @@ describe('verify', () => {
   const ENGINE_PRIVATE_KEY = '7cfef3303797cbc7515d9ce22ffe849c701b0f2812f999b0847229c47951fca5'
 
   it('should verify a EIP191-signed JWT', async () => {
-    const jwk = ellipticPrivateKeyToJwk(`0x${ENGINE_PRIVATE_KEY}`)
+    const jwk = secp256k1PrivateKeyToJwk(`0x${ENGINE_PRIVATE_KEY}`)
 
     const header = {
       kid: '0x2c4895215973CbBd778C32c456C074b99daF8Bf1',
diff --git a/packages/signature/src/lib/schemas.ts b/packages/signature/src/lib/schemas.ts
index 1e6ac7744..8fdf1eb8b 100644
--- a/packages/signature/src/lib/schemas.ts
+++ b/packages/signature/src/lib/schemas.ts
@@ -84,6 +84,8 @@ export const secp256k1KeySchema = z.union([secp256k1PublicKeySchema, secp256k1Pr
 
 export const p256KeySchema = z.union([p256PublicKeySchema, p256PrivateKeySchema])
 
+export const ellipticKeySchema = z.union([secp256k1KeySchema, p256KeySchema])
+
 const dynamicKeySchema = z.object({}).catchall(z.unknown())
 
 export const jwkSchema = dynamicKeySchema.extend({
diff --git a/packages/signature/src/lib/sign.ts b/packages/signature/src/lib/sign.ts
index f8e277391..0c0598789 100644
--- a/packages/signature/src/lib/sign.ts
+++ b/packages/signature/src/lib/sign.ts
@@ -69,22 +69,40 @@ export async function signJwt(
  */
 export async function signJwt(payload: Payload, jwk: Jwk, opts: { alg?: SigningAlg }): Promise<string>
 
+/**
+ * Signs using default signers per algorithm. Key private material is required.
+ * opts are not provided
+ * @param payload
+ * @param jwk
+ * @returns
+ */
+export async function signJwt(payload: Payload, jwk: Jwk): Promise<string>
+
 export async function signJwt(
   payload: Payload,
   jwk: Jwk,
-  opts: { alg?: SigningAlg } = {},
+  optsOrSigner?: { alg?: SigningAlg } | ((payload: string) => Promise<string>),
   signer?: (payload: string) => Promise<string>
 ): Promise<string> {
+  let opts: { alg?: SigningAlg } = {}
+  let actualSigner: ((payload: string) => Promise<string>) | undefined = undefined
+
+  if (typeof optsOrSigner === 'function') {
+    actualSigner = optsOrSigner
+  } else {
+    opts = optsOrSigner || {}
+    actualSigner = signer
+  }
+
   const header = buildHeader(jwk, opts.alg)
   const encodedHeader = base64url.encode(JSON.stringify(header))
   const encodedPayload = base64url.encode(JSON.stringify(payload))
   const messageToSign = `${encodedHeader}.${encodedPayload}`
 
-  // Signature logic based on the presence of a custom signer
+  // Determine the signing logic based on the presence of a custom signer
   let signature: string
-  if (signer) {
-    // Custom signer provided
-    signature = await signer(messageToSign)
+  if (actualSigner) {
+    signature = await actualSigner(messageToSign)
   } else {
     // Default signer logic
     // Validate JWK as a private key for default signing
@@ -105,6 +123,7 @@ export async function signJwt(
         return fallbackSigner(privateKey, payload, header)
     }
   }
+
   return `${messageToSign}.${signature}`
 }
 
diff --git a/packages/signature/src/lib/types.ts b/packages/signature/src/lib/types.ts
index 9a657724a..1bfe18519 100644
--- a/packages/signature/src/lib/types.ts
+++ b/packages/signature/src/lib/types.ts
@@ -1,5 +1,6 @@
 import { z } from 'zod'
 import {
+  ellipticKeySchema,
   jwkBaseSchema,
   jwkEoaSchema,
   jwkSchema,
@@ -63,6 +64,7 @@ export type RsaKey = RsaPrivateKey | RsaPublicKey
 export type EoaPublicKey = z.infer<typeof jwkEoaSchema>
 export type Secp256k1PublicKey = z.infer<typeof secp256k1PublicKeySchema>
 export type Secp256k1Key = z.infer<typeof secp256k1KeySchema>
+export type EllipticKey = z.infer<typeof ellipticKeySchema>
 export type PublicKey = z.infer<typeof publicKeySchema>
 export type PrivateKey = z.infer<typeof privateKeySchema>
 export type PartialJwk = z.infer<typeof jwkBaseSchema>
diff --git a/packages/signature/src/lib/utils.ts b/packages/signature/src/lib/utils.ts
index 925e7db8e..e9c555f71 100644
--- a/packages/signature/src/lib/utils.ts
+++ b/packages/signature/src/lib/utils.ts
@@ -5,10 +5,11 @@ import { exportJWK, generateKeyPair } from 'jose'
 import { toHex } from 'viem'
 import { publicKeyToAddress } from 'viem/utils'
 import { JwtError } from './error'
-import { privateKeySchema, rsaPrivateKeySchema, rsaPublicKeySchema, secp256k1KeySchema } from './schemas'
+import { ellipticKeySchema, privateKeySchema, rsaPrivateKeySchema, rsaPublicKeySchema } from './schemas'
 import {
   Alg,
   Curves,
+  EllipticKey,
   Hex,
   Jwk,
   KeyTypes,
@@ -17,7 +18,6 @@ import {
   PrivateKey,
   RsaPrivateKey,
   RsaPublicKey,
-  Secp256k1Key,
   Secp256k1PrivateKey,
   Secp256k1PublicKey,
   Use
@@ -90,7 +90,7 @@ export const p256PublicKeyToJwk = (publicKey: Hex, keyId?: string): P256PublicKe
 }
 
 // ES256k
-export const ellipticPrivateKeyToJwk = (privateKey: Hex, keyId?: string): Secp256k1PrivateKey => {
+export const secp256k1PrivateKeyToJwk = (privateKey: Hex, keyId?: string): Secp256k1PrivateKey | P256PrivateKey => {
   const publicKey = toHex(secp256k1.getPublicKey(privateKey.slice(2), false))
   const publicJwk = secp256k1PublicKeyToJwk(publicKey, keyId)
   return {
@@ -108,9 +108,9 @@ export const p256PrivateKeyToJwk = (privateKey: Hex, keyId?: string): P256Privat
   }
 }
 
-export const ellicpticPublicKeyToHex = (jwk: Jwk): Hex => {
-  const key = validate<Secp256k1Key>({
-    schema: secp256k1KeySchema,
+export const ellipticPublicKeyToHex = (jwk: Jwk): Hex => {
+  const key = validate<EllipticKey>({
+    schema: ellipticKeySchema,
     jwk: jwk,
     errorMessage: 'Invalid Public Key'
   })
@@ -134,6 +134,20 @@ export const ellicpticPublicKeyToHex = (jwk: Jwk): Hex => {
   return `0x04${x.slice(2)}${y.slice(2)}`
 }
 
+export const publicKeyToJwk = (jwk: Hex, alg: Alg): Jwk => {
+  switch (alg) {
+    case Alg.ES256K:
+      return secp256k1PublicKeyToJwk(jwk)
+    case Alg.ES256:
+      return p256PublicKeyToJwk(jwk)
+    case Alg.RS256:
+      throw new JwtError({
+        message: 'Conversion from Hex to JWK not supported for RSA keys',
+        context: { jwk }
+      })
+  }
+}
+
 export const ellipticPrivateKeyToHex = (jwk: P256PrivateKey | Secp256k1PrivateKey): Hex => {
   return base64UrlToHex(jwk.d)
 }
@@ -199,7 +213,7 @@ const rsaPrivateKeyToHex = (jwk: Jwk): Hex => {
 
 export const publicKeyToHex = (jwk: Jwk): Hex => {
   if (jwk.kty === KeyTypes.EC) {
-    return ellicpticPublicKeyToHex(jwk)
+    return ellipticPublicKeyToHex(jwk)
   }
   return rsaPubKeyToHex(jwk)
 }
@@ -219,7 +233,7 @@ export const privateKeyToHex = (jwk: Jwk): Hex => {
 export const privateKeyToJwk = (jwk: Hex, alg: Alg): PrivateKey => {
   switch (alg) {
     case Alg.ES256K:
-      return ellipticPrivateKeyToJwk(jwk)
+      return secp256k1PrivateKeyToJwk(jwk)
     case Alg.ES256:
       return p256PrivateKeyToJwk(jwk)
     case Alg.RS256:
@@ -282,7 +296,7 @@ export const generateJwk = async <T = Jwk>(
   switch (alg) {
     case Alg.ES256K: {
       const privateKeyK1 = toHex(secp256k1.utils.randomPrivateKey())
-      return ellipticPrivateKeyToJwk(privateKeyK1, opts?.keyId) as T
+      return secp256k1PrivateKeyToJwk(privateKeyK1, opts?.keyId) as T
     }
     case Alg.ES256: {
       const privateKeyP256 = toHex(p256.utils.randomPrivateKey())
diff --git a/packages/signature/src/lib/verify.ts b/packages/signature/src/lib/verify.ts
index 83b6b5137..ea7739d4d 100644
--- a/packages/signature/src/lib/verify.ts
+++ b/packages/signature/src/lib/verify.ts
@@ -6,7 +6,7 @@ import { JwtError } from './error'
 import { eip191Hash } from './sign'
 import { isSepc256k1PublicKeyJwk } from './typeguards'
 import { Alg, Hex, Jwk, Jwt, Payload, PublicKey, Secp256k1PublicKey, SigningAlg } from './types'
-import { base64UrlToHex, ellicpticPublicKeyToHex, publicKeyToHex } from './utils'
+import { base64UrlToHex, ellipticPublicKeyToHex, publicKeyToHex } from './utils'
 
 const checkTokenExpiration = (payload: Payload): boolean => {
   const now = Math.floor(Date.now() / 1000)
@@ -45,7 +45,7 @@ const verifyEip191WithPublicKey = async (sig: Hex, hash: Uint8Array, jwk: Public
 }
 
 export const verifySepc256k1 = async (sig: Hex, hash: Uint8Array, jwk: Secp256k1PublicKey): Promise<boolean> => {
-  const pubKey = ellicpticPublicKeyToHex(jwk)
+  const pubKey = ellipticPublicKeyToHex(jwk)
   const isValid = secp256k1.verify(sig.slice(2, 130), hash, pubKey.slice(2)) === true
   return isValid
 }
diff --git a/packages/transaction-request-intent/src/lib/intent.types.ts b/packages/transaction-request-intent/src/lib/intent.types.ts
index c1dce01c7..796ea4854 100644
--- a/packages/transaction-request-intent/src/lib/intent.types.ts
+++ b/packages/transaction-request-intent/src/lib/intent.types.ts
@@ -1,7 +1,7 @@
-import { AccountId, AssetId, Hex } from '@narval/policy-engine-shared'
+import { AccountId, AssetId, Eip712Domain, Hex } from '@narval/policy-engine-shared'
 import { Alg } from '@narval/signature'
 import { Address } from 'viem'
-import { Eip712Domain, Intents } from './domain'
+import { Intents } from './domain'
 
 export type TransferNative = {
   type: Intents.TRANSFER_NATIVE