diff --git a/examples/emissions/co2-sensor/Dockerfile b/examples/emissions/Dockerfile
similarity index 78%
rename from examples/emissions/co2-sensor/Dockerfile
rename to examples/emissions/Dockerfile
index a0a86d9..e13aef5 100644
--- a/examples/emissions/co2-sensor/Dockerfile
+++ b/examples/emissions/Dockerfile
@@ -1,3 +1,5 @@
+# An image with holochain, lair-keystore, hc and node tsx
+
 # We use ubuntu as it's glibc version is compatible with the prebuilt binaries
 FROM ubuntu
 
@@ -24,13 +26,9 @@ RUN chmod 755 /usr/local/bin/hc /usr/local/bin/holochain /usr/local/bin/lair-key
 WORKDIR /home/node
 RUN /bin/bash -c "source $NVM_DIR/nvm.sh && npm i tsx"
 
-# Copy the actual server script
-COPY ./co2-sensor.ts ./co2-sensor.ts
+COPY ./start.sh ./start.sh
+RUN chmod +x ./start.sh
 
 # So container runs with nvm loaded
 SHELL ["/bin/bash", "--login", "-c"]
-
-# The ./packages directory is mounted from the locally built npm workspace. We
-# npm install at launch to avoid the need for the package.json to know the 
-# latest version or features of the workspace.
-CMD npm install ./packages/types ./packages/sandbox; npx tsx ./co2-sensor.ts
+CMD ["./start.sh"]
\ No newline at end of file
diff --git a/examples/emissions/co2-sensor/co2-sensor.ts b/examples/emissions/agents/co2-sensor.ts
similarity index 90%
rename from examples/emissions/co2-sensor/co2-sensor.ts
rename to examples/emissions/agents/co2-sensor.ts
index 3830332..faa2c9f 100644
--- a/examples/emissions/co2-sensor/co2-sensor.ts
+++ b/examples/emissions/agents/co2-sensor.ts
@@ -18,6 +18,14 @@ async function main() {
     {
       bootstrapServerUrl: new URL("https://bootstrap-0.infra.holochain.org"),
       signalingServerUrl: new URL("wss://sbd-0.main.infra.holo.host"),
+      iceServers: [
+        "stun:stun-0.main.infra.holo.host:443",
+        "stun:stun-1.main.infra.holo.host:443",
+      ],
+      ephemeralPorts: {
+        min: "40000",
+        max: "40255",
+      },
       password: "password",
     }
   );
@@ -46,7 +54,7 @@ async function ensureListedAsPublisher(
 function arrEqual(arr1: Uint8Array, arr2: Uint8Array): boolean {
   if (arr1.length !== arr2.length) return false;
   for (let i = 0; i < arr1.length; i++) {
-    if (arr1![i] !== arr2[i]) return false;
+    if (arr1[i] !== arr2[i]) return false;
   }
   return true;
 }
diff --git a/examples/emissions/agents/token-mint-signer.ts b/examples/emissions/agents/token-mint-signer.ts
new file mode 100644
index 0000000..cd28fe0
--- /dev/null
+++ b/examples/emissions/agents/token-mint-signer.ts
@@ -0,0 +1,219 @@
+/**
+ * A mock CO₂ sensor, that emits a random measure in grams roughly every 2
+ * seconds. The "measurements" are published by a sandboxed holochain agent
+ * that serves no other role in the network.
+ */
+
+import { ensureAndConnectToHapp } from "@holoom/sandbox";
+import {
+  UsernameRegistryCoordinator,
+  RecordsCoordinator,
+  Recipe,
+  SignedEvmSigningOffer,
+  EvmU256Item,
+} from "@holoom/types";
+import { encodeHashToBase64, AppClient, AgentPubKey } from "@holochain/client";
+import {
+  BytesSigner,
+  EvmBytesSignerClient,
+  OfferCreator,
+} from "@holoom/authority";
+import { decodeAppEntry } from "@holoom/client";
+
+async function main() {
+  // Create a conductor sandbox (with holoom installed) at the specified
+  // directory if it doesn't already exist, and connect to it.
+  const { appWs } = await ensureAndConnectToHapp(
+    "/sandbox",
+    "/workdir/holoom.happ",
+    "emissions-local-test-2024-09-04T12:59",
+    {
+      bootstrapServerUrl: new URL("https://bootstrap-0.infra.holochain.org"),
+      signalingServerUrl: new URL("wss://sbd-0.main.infra.holo.host"),
+      iceServers: [
+        "stun:stun-0.main.infra.holo.host:443",
+        "stun:stun-1.main.infra.holo.host:443",
+      ],
+      ephemeralPorts: {
+        min: "40300",
+        max: "40555",
+      },
+      password: "password",
+    }
+  );
+  const app = new TokenMintSigner(appWs);
+  await app.run();
+}
+
+// Auto creates a recipe + offer as defined below and listens for signing requests
+class TokenMintSigner {
+  bytesSigner: BytesSigner;
+  offerCreator: OfferCreator;
+  usernameRegistryCoordinator: UsernameRegistryCoordinator;
+  recordsCoordinator: RecordsCoordinator;
+  evmBytesSignerClient: EvmBytesSignerClient;
+  constructor(appClient: AppClient) {
+    // First private key of seed phrase:
+    // test test test test test test test test test test test junk
+    const EVM_PRIVATE_KEY =
+      "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80";
+    this.bytesSigner = new BytesSigner(EVM_PRIVATE_KEY);
+    this.offerCreator = new OfferCreator(appClient, this.bytesSigner);
+    this.usernameRegistryCoordinator = new UsernameRegistryCoordinator(
+      appClient
+    );
+    this.recordsCoordinator = new RecordsCoordinator(appClient);
+    this.evmBytesSignerClient = new EvmBytesSignerClient(
+      appClient,
+      this.bytesSigner
+    );
+  }
+
+  async run() {
+    await this.autoPublishSigningOfferAndRecipe();
+    // Start listening for requests
+    await this.evmBytesSignerClient.setup();
+  }
+
+  // In a more realistic setup this step would be action manually by a human who
+  // has convinced themselves of which agent(s) they want to use as a data
+  // source. This example automates this step to reduce test tedium.
+  async autoPublishSigningOfferAndRecipe() {
+    console.log("Waiting for co2-sensor author to appear");
+    const co2SensorAuthor = await this.untilTrustedAuthorSelected();
+    console.log(
+      `Trusting ${encodeHashToBase64(co2SensorAuthor)} as co2-sensor author`
+    );
+
+    await this.ensureRecipe(...recipeForMint(co2SensorAuthor));
+  }
+
+  async untilTrustedAuthorSelected() {
+    while (true) {
+      const publishers =
+        await this.usernameRegistryCoordinator.getAllPublishers();
+      const pair = publishers.find(([_, tag]) => tag === "co2-sensor");
+      if (pair) return pair[0];
+      await new Promise((r) => setTimeout(r, 1000));
+    }
+  }
+
+  async ensureRecipe(expectedRecipe: Recipe, expectU256Items: EvmU256Item[]) {
+    const offerAhs =
+      await this.usernameRegistryCoordinator.getSigningOfferAhsForEvmAddress(
+        this.bytesSigner.address
+      );
+
+    for (const offerAh of offerAhs) {
+      const offerRecord = await this.recordsCoordinator.getRecord(offerAh);
+      if (!offerRecord) {
+        console.warn(
+          `Signing offer record ${encodeHashToBase64(offerAh)} not found`
+        );
+        continue;
+      }
+      const signedSigningOffer =
+        decodeAppEntry<SignedEvmSigningOffer>(offerRecord);
+      const recipeRecord = await this.recordsCoordinator.getRecord(
+        signedSigningOffer.offer.recipe_ah
+      );
+      if (!recipeRecord) {
+        console.warn(`Recipe record ${encodeHashToBase64(offerAh)} not found`);
+        continue;
+      }
+      const recipe = decodeAppEntry<Recipe>(recipeRecord);
+      if (
+        deepEqual(recipe, expectedRecipe) &&
+        deepEqual(signedSigningOffer.offer.u256_items, expectU256Items)
+      ) {
+        console.log(
+          `Found existing matching signing offer ${encodeHashToBase64(
+            offerAh
+          )} and recipe ${encodeHashToBase64(
+            recipeRecord.signed_action.hashed.hash
+          )}`
+        );
+      }
+    }
+    const createdRecipeRecord =
+      await this.usernameRegistryCoordinator.createRecipe(expectedRecipe);
+    const createdSigningOfferRecord = await this.offerCreator.createOffer(
+      "mint-credit",
+      createdRecipeRecord.signed_action.hashed.hash,
+      expectU256Items
+    );
+    console.log(
+      `Create recipe ${encodeHashToBase64(
+        createdRecipeRecord.signed_action.hashed.hash
+      )} with offer ${createdSigningOfferRecord.signed_action.hashed.hash}`
+    );
+  }
+}
+
+const JQ_RANGE_TO_NAMES = `
+[range(.from | tonumber; .until | tonumber)] |
+map("co2-sensor/time/\\(.)")
+`;
+
+const JQ_ADD_READINGS = `
+map(.gramsCo2) | add | [.]
+`;
+
+function recipeForMint(
+  trustedCo2SensorAuthor: AgentPubKey
+): [Recipe, EvmU256Item[]] {
+  const recipe: Recipe = {
+    trusted_authors: [trustedCo2SensorAuthor],
+    arguments: [
+      ["from", { type: "String" }],
+      ["until", { type: "String" }],
+    ],
+    instructions: [
+      [
+        "reading_names",
+        {
+          type: "Jq",
+          input_var_names: { type: "List", var_names: ["from", "until"] },
+          program: JQ_RANGE_TO_NAMES,
+        },
+      ],
+      ["readings", { type: "GetDocsListedByVar", var_name: "reading_names" }],
+      [
+        "$return",
+        {
+          type: "Jq",
+          input_var_names: { type: "Single", var_name: "readings" },
+          program: JQ_ADD_READINGS,
+        },
+      ],
+    ],
+  };
+  const items: EvmU256Item[] = [{ type: "Uint" }];
+  return [recipe, items];
+}
+
+function deepEqual(x: unknown, y: unknown) {
+  if (x === y) {
+    return true;
+  }
+  // Not shallowly equal, therefore only possible to be deeply equal if both
+  // are instances.
+  if (typeof x !== "object" || !x || typeof y !== "object" || !y) {
+    return false;
+  }
+  if (Object.keys(x).length != Object.keys(y).length) {
+    return false;
+  }
+  for (const prop in x) {
+    if (!y.hasOwnProperty(prop)) {
+      return false;
+    }
+    if (!deepEqual(x[prop as keyof typeof x], y[prop as keyof typeof x])) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+main();
diff --git a/examples/emissions/docker-compose.yaml b/examples/emissions/docker-compose.yaml
index 66b718e..165c8cd 100644
--- a/examples/emissions/docker-compose.yaml
+++ b/examples/emissions/docker-compose.yaml
@@ -1,7 +1,19 @@
 services:
 
   co2-sensor:
-    build: ./co2-sensor
+    build: .
     volumes:
+      - ./agents/co2-sensor.ts:/home/node/agent.ts
       - ../../packages:/home/node/packages
-      - ../../workdir:/workdir
\ No newline at end of file
+      - ../../workdir:/workdir
+    ports:
+      - 40000-40255:40000-40255
+
+  token-mint-signer:
+    build: .
+    volumes:
+      - ./agents/token-mint-signer.ts:/home/node/agent.ts
+      - ../../packages:/home/node/packages
+      - ../../workdir:/workdir
+    ports:
+      - 40300-40555:40300-40555
\ No newline at end of file
diff --git a/examples/emissions/start.sh b/examples/emissions/start.sh
new file mode 100644
index 0000000..ed2bfe6
--- /dev/null
+++ b/examples/emissions/start.sh
@@ -0,0 +1,20 @@
+#! /bin/bash
+set -e
+npm install ./packages/types ./packages/authority ./packages/client ./packages/sandbox
+
+# Link installed modules to volume for latest changes
+cd ./packages/types
+npm link
+cd ../authority
+npm link
+cd ../client
+npm link
+cd ../sandbox
+npm link
+cd ../..
+npm link @holoom/types
+npm link @holoom/authority
+npm link @holoom/client
+npm link @holoom/sandbox
+
+npx tsx watch ./agent.ts
diff --git a/packages/authority/src/evm-bytes-signer/offer-creator.ts b/packages/authority/src/evm-bytes-signer/offer-creator.ts
index ca6df50..a717025 100644
--- a/packages/authority/src/evm-bytes-signer/offer-creator.ts
+++ b/packages/authority/src/evm-bytes-signer/offer-creator.ts
@@ -1,6 +1,5 @@
 import { ActionHash, AppClient, Record } from "@holochain/client";
 import {
-  CreateEvmSigningOfferPayload,
   EvmSigningOffer,
   EvmU256Item,
   RecordsCoordinator,
@@ -23,7 +22,7 @@ export class OfferCreator {
 
   async createOffer(
     identifier: string,
-    recipeAh: number[],
+    recipeAh: ActionHash,
     items: EvmU256Item[]
   ) {
     const offer: EvmSigningOffer = {
@@ -45,8 +44,7 @@ export class OfferCreator {
         },
       });
     console.log("Created record", record);
-    const actionHash = Array.from(record.signed_action.hashed.hash);
-    return actionHash;
+    return record;
   }
 
   private async untilRecipeGossiped(recipeAh: ActionHash) {
diff --git a/packages/sandbox/src/sandbox.ts b/packages/sandbox/src/sandbox.ts
index d4e5125..05c70a6 100644
--- a/packages/sandbox/src/sandbox.ts
+++ b/packages/sandbox/src/sandbox.ts
@@ -5,6 +5,8 @@ import yaml from "yaml";
 export interface SandboxOptions {
   bootstrapServerUrl: URL;
   signalingServerUrl: URL;
+  iceServers: string[];
+  ephemeralPorts?: { min: string; max: string };
   password: string;
 }
 
@@ -86,12 +88,25 @@ export async function createSandbox(path: string, options: SandboxOptions) {
   });
   await createConductorPromise;
 
-  // Disable dpki
+  // Tweak conductor config
   const conductorConfigPath = `${path}/conductor-config.yaml`;
   const conductorConfig = yaml.parse(
     await fs.readFile(conductorConfigPath, "utf8")
   );
+  // Disable dpki
   conductorConfig.dpki.no_dpki = true;
+  // Set WebRTC config
+  conductorConfig.network.transport_pool[0].webrtc_config = options.iceServers
+    .length
+    ? { iceServers: options.iceServers.map((url) => ({ url })) }
+    : null;
+  // Set ephemeral port range
+  if (options.ephemeralPorts) {
+    conductorConfig.network.tuning_params.tx5_min_ephemeral_udp_port =
+      options.ephemeralPorts.min;
+    conductorConfig.network.tuning_params.tx5_max_ephemeral_udp_port =
+      options.ephemeralPorts.max;
+  }
   await fs.writeFile(conductorConfigPath, yaml.stringify(conductorConfig));
 }
 
diff --git a/packages/tryorama/src/e2e/signing-offer.test.ts b/packages/tryorama/src/e2e/signing-offer.test.ts
index 79f7b0b..90c1932 100644
--- a/packages/tryorama/src/e2e/signing-offer.test.ts
+++ b/packages/tryorama/src/e2e/signing-offer.test.ts
@@ -68,7 +68,7 @@ test("e2e signing offer", async () => {
     // This would normally be behind an admin authorised POST endpoint
     await evmBytesSignerService.offerCreator.createOffer(
       "123",
-      Array.from(recipeRecord.signed_action.hashed.hash),
+      recipeRecord.signed_action.hashed.hash,
       [
         { type: "Uint" },
         { type: "Hex" },
@@ -95,7 +95,8 @@ test("e2e signing offer", async () => {
       });
 
     const evmSignedResult = await new HoloomClient(
-      alice.appWs as AppClient
+      alice.appWs as AppClient,
+      authority.agentPubKey
     ).requestEvmSignatureOverRecipeExecutionResult(
       recipeExecutionRecord.signed_action.hashed.hash,
       signingOfferAh