diff --git a/packages/core/src/api-client.test.ts b/packages/core/src/api-client.test.ts
index 6dbe713..45747cb 100644
--- a/packages/core/src/api-client.test.ts
+++ b/packages/core/src/api-client.test.ts
@@ -1,55 +1,149 @@
 import { setupJest } from "../mocks/server";
-import { ArgosApiClient, createArgosApiClient } from "./api-client";
+import {
+  ArgosApiClient,
+  createArgosApiClient,
+  getBearerToken,
+} from "./api-client";
 
 setupJest();
 
 let apiClient: ArgosApiClient;
-beforeAll(() => {
-  apiClient = createArgosApiClient({
-    baseUrl: "https://api.argos-ci.dev",
-    token: "92d832e0d22ab113c8979d73a87a11130eaa24a9",
+
+describe("#createArgosApiClient", () => {
+  beforeAll(() => {
+    apiClient = createArgosApiClient({
+      baseUrl: "https://api.argos-ci.dev",
+      bearerToken: "Bearer 92d832e0d22ab113c8979d73a87a11130eaa24a9",
+    });
   });
-});
 
-describe("#createBuild", () => {
-  it("creates build", async () => {
-    const result = await apiClient.createBuild({
-      commit: "f16f980bd17cccfa93a1ae7766727e67950773d0",
-      screenshotKeys: ["123", "456"],
-    });
-    expect(result).toEqual({
-      build: {
-        id: "123",
-        url: "https://app.argos-ci.dev/builds/123",
-      },
-      screenshots: [
-        {
-          key: "123",
-          putUrl: "https://api.s3.dev/upload/123",
+  describe("#createBuild", () => {
+    it("creates build", async () => {
+      const result = await apiClient.createBuild({
+        commit: "f16f980bd17cccfa93a1ae7766727e67950773d0",
+        screenshotKeys: ["123", "456"],
+      });
+      expect(result).toEqual({
+        build: {
+          id: "123",
+          url: "https://app.argos-ci.dev/builds/123",
         },
-        {
-          key: "456",
-          putUrl: "https://api.s3.dev/upload/456",
+        screenshots: [
+          {
+            key: "123",
+            putUrl: "https://api.s3.dev/upload/123",
+          },
+          {
+            key: "456",
+            putUrl: "https://api.s3.dev/upload/456",
+          },
+        ],
+      });
+    });
+  });
+
+  describe("#updateBuild", () => {
+    it("updates build", async () => {
+      const result = await apiClient.updateBuild({
+        buildId: "123",
+        screenshots: [
+          { key: "123", name: "screenshot 1" },
+          { key: "456", name: "screenshot 2" },
+        ],
+      });
+      expect(result).toEqual({
+        build: {
+          id: "123",
+          url: "https://app.argos-ci.dev/builds/123",
         },
-      ],
+      });
     });
   });
 });
 
-describe("#updateBuild", () => {
-  it("updates build", async () => {
-    const result = await apiClient.updateBuild({
-      buildId: "123",
-      screenshots: [
-        { key: "123", name: "screenshot 1" },
-        { key: "456", name: "screenshot 2" },
-      ],
-    });
-    expect(result).toEqual({
-      build: {
-        id: "123",
-        url: "https://app.argos-ci.dev/builds/123",
-      },
+describe("#getBearerToken", () => {
+  describe("without CI", () => {
+    describe("without token", () => {
+      it("should throw", () => {
+        const config = {};
+        expect(() => getBearerToken(config)).toThrow(
+          "Missing Argos repository token 'ARGOS_TOKEN'"
+        );
+      });
+    });
+
+    describe("with token", () => {
+      it("should return bearer token", () => {
+        const config = { token: "this-token" };
+        expect(getBearerToken(config)).toBe(`Bearer this-token`);
+      });
+    });
+  });
+
+  describe("with unknown CI", () => {
+    const configProps = { ciService: "unknownCI" };
+
+    describe("without token", () => {
+      it("should throw", () => {
+        const config = { ...configProps };
+        expect(() => getBearerToken(config)).toThrow(
+          "Missing Argos repository token 'ARGOS_TOKEN'"
+        );
+      });
+    });
+
+    describe("with token", () => {
+      it("should return bearer token", () => {
+        const config = { ...configProps, token: "this-token" };
+        expect(getBearerToken(config)).toBe(`Bearer this-token`);
+      });
+    });
+  });
+
+  describe("with Github Actions CI", () => {
+    const configProps = { ciService: "GitHub Actions" };
+
+    describe("with token", () => {
+      it("should return bearer token", () => {
+        const config = { ...configProps, token: "this-token" };
+        expect(getBearerToken(config)).toBe(`Bearer this-token`);
+      });
+    });
+
+    describe("without token but with CI env variables", () => {
+      it("should return a composite token", () => {
+        const config = {
+          ...configProps,
+          owner: "this-owner",
+          repository: "this-repository",
+          jobId: "this-jobId",
+        };
+
+        const base64 = Buffer.from(
+          JSON.stringify({
+            owner: config.owner,
+            repository: config.repository,
+            jobId: config.jobId,
+          }),
+          "utf8"
+        ).toString("base64");
+
+        const bearerToken = getBearerToken(config);
+
+        expect(bearerToken).toBe(`Bearer tokenless-github-${base64}`);
+        expect(bearerToken).toBe(
+          "Bearer tokenless-github-eyJvd25lciI6InRoaXMtb3duZXIiLCJyZXBvc2l0b3J5IjoidGhpcy1yZXBvc2l0b3J5Iiwiam9iSWQiOiJ0aGlzLWpvYklkIn0="
+        );
+      });
+    });
+
+    describe("without token and without CI env variables", () => {
+      it("should throw", () => {
+        const config = { ...configProps };
+        expect(() => getBearerToken(config)).toThrow(
+          "Automatic GitHub Actions variables detection failed. Please add the 'ARGOS_TOKEN'"
+        );
+      });
     });
   });
 });
diff --git a/packages/core/src/api-client.ts b/packages/core/src/api-client.ts
index 1b54bbf..f344260 100644
--- a/packages/core/src/api-client.ts
+++ b/packages/core/src/api-client.ts
@@ -2,7 +2,7 @@ import axios from "axios";
 
 export interface ApiClientOptions {
   baseUrl: string;
-  token: string;
+  bearerToken: string;
 }
 
 export interface CreateBuildInput {
@@ -44,13 +44,51 @@ export interface ArgosApiClient {
   updateBuild: (input: UpdateBuildInput) => Promise<UpdateBuildOutput>;
 }
 
+const base64Encode = (obj: any) =>
+  Buffer.from(JSON.stringify(obj), "utf8").toString("base64");
+
+export const getBearerToken = ({
+  token,
+  ciService,
+  owner,
+  repository,
+  jobId,
+}: {
+  token?: string | null;
+  ciService?: string | null;
+  owner?: string | null;
+  repository?: string | null;
+  jobId?: string | null;
+}) => {
+  if (token) return `Bearer ${token}`;
+
+  switch (ciService) {
+    case "GitHub Actions": {
+      if (!owner || !repository || !jobId) {
+        throw new Error(
+          `Automatic ${ciService} variables detection failed. Please add the 'ARGOS_TOKEN'`
+        );
+      }
+
+      return `Bearer tokenless-github-${base64Encode({
+        owner,
+        repository,
+        jobId,
+      })}`;
+    }
+
+    default:
+      throw new Error("Missing Argos repository token 'ARGOS_TOKEN'");
+  }
+};
+
 export const createArgosApiClient = (
   options: ApiClientOptions
 ): ArgosApiClient => {
   const axiosInstance = axios.create({
     baseURL: options.baseUrl,
     headers: {
-      Authorization: `Bearer ${options.token}`,
+      Authorization: options.bearerToken,
       "Content-Type": "application/json",
       Accept: "application/json",
     },
diff --git a/packages/core/src/ci-environment/index.ts b/packages/core/src/ci-environment/index.ts
index 2fc2156..decbc25 100644
--- a/packages/core/src/ci-environment/index.ts
+++ b/packages/core/src/ci-environment/index.ts
@@ -27,6 +27,10 @@ export const getCiEnvironment = ({
     : null;
   const commit = ciContext.commit ?? null;
   const branch = (ciContext.branch || ciContext.prBranch) ?? null;
+  const slug = ciContext.slug ? ciContext.slug.split("/") : null;
+  const owner = slug ? slug[0] : null;
+  const repository = slug ? slug[1] : null;
+  const jobId = ciContext.job ?? null;
 
-  return commit ? { name, commit, branch } : null;
+  return commit ? { name, commit, branch, owner, repository, jobId } : null;
 };
diff --git a/packages/core/src/ci-environment/services/github-actions.ts b/packages/core/src/ci-environment/services/github-actions.ts
index d6ce14c..ee90a8f 100644
--- a/packages/core/src/ci-environment/services/github-actions.ts
+++ b/packages/core/src/ci-environment/services/github-actions.ts
@@ -62,9 +62,12 @@ function getBranch({ env }: Context) {
 const service: Service = {
   detect: ({ env }) => Boolean(env.GITHUB_ACTIONS),
   config: ({ env }) => ({
-    name: "GiHub Actions",
+    name: "GitHub Actions",
     commit: getSha({ env }),
     branch: getBranch({ env }),
+    owner: env.GITHUB_REPOSITORY_OWNER || null,
+    repository: env.GITHUB_REPOSITORY || null,
+    jobId: env.GITHUB_JOB || null,
   }),
 };
 
diff --git a/packages/core/src/ci-environment/services/heroku.ts b/packages/core/src/ci-environment/services/heroku.ts
index c61d9c4..b77e1fa 100644
--- a/packages/core/src/ci-environment/services/heroku.ts
+++ b/packages/core/src/ci-environment/services/heroku.ts
@@ -6,6 +6,9 @@ const service: Service = {
     name: "Heroku",
     commit: env.HEROKU_TEST_RUN_COMMIT_VERSION || null,
     branch: env.HEROKU_TEST_RUN_BRANCH || null,
+    owner: null,
+    repository: null,
+    jobId: env.HEROKU_TEST_RUN_ID || null,
   }),
 };
 
diff --git a/packages/core/src/ci-environment/types.ts b/packages/core/src/ci-environment/types.ts
index a7e0309..03ed10f 100644
--- a/packages/core/src/ci-environment/types.ts
+++ b/packages/core/src/ci-environment/types.ts
@@ -10,6 +10,9 @@ export interface CiEnvironment {
   name: string | null;
   commit: string | null;
   branch: string | null;
+  owner: string | null;
+  repository: string | null;
+  jobId: string | null;
 }
 
 export interface Service {
diff --git a/packages/core/src/config.test.ts b/packages/core/src/config.test.ts
index ee31d98..1d961fc 100644
--- a/packages/core/src/config.test.ts
+++ b/packages/core/src/config.test.ts
@@ -3,26 +3,24 @@ import { createConfig } from "./config";
 describe("#createConfig", () => {
   it("gets config", () => {
     const config = createConfig();
-    config.load({
-      commit: "f16f980bd17cccfa93a1ae7766727e67950773d0",
-      token: "92d832e0d22ab113c8979d73a87a11130eaa24a9",
-    });
+    config.load({ commit: "f16f980bd17cccfa93a1ae7766727e67950773d0" });
     expect(config.get()).toEqual({
       apiBaseUrl: "https://api.argos-ci.com/v2/",
       commit: "f16f980bd17cccfa93a1ae7766727e67950773d0",
       branch: null,
-      token: "92d832e0d22ab113c8979d73a87a11130eaa24a9",
+      token: null,
       buildName: null,
       parallel: false,
       parallelNonce: null,
       parallelTotal: null,
       ciService: null,
+      jobId: null,
+      repository: null,
+      owner: null,
     });
   });
 
   it("throws with invalid commit", () => {
-    expect(() => createConfig().validate()).toThrow(
-      "commit: Invalid commit\ntoken: Must be a valid Argos repository token"
-    );
+    expect(() => createConfig().validate()).toThrow("commit: Invalid commit");
   });
 });
diff --git a/packages/core/src/config.ts b/packages/core/src/config.ts
index 8d8d3f0..734a6c2 100644
--- a/packages/core/src/config.ts
+++ b/packages/core/src/config.ts
@@ -22,7 +22,7 @@ const mustBeCommit = (value: any) => {
 };
 
 const mustBeArgosToken = (value: any) => {
-  if (value.length !== 40) {
+  if (value && value.length !== 40) {
     throw new Error("Must be a valid Argos repository token");
   }
 };
@@ -46,7 +46,7 @@ const schema = {
   },
   token: {
     env: "ARGOS_TOKEN",
-    default: "",
+    default: null,
     format: mustBeArgosToken,
   },
   buildName: {
@@ -77,17 +77,35 @@ const schema = {
     default: null,
     nullable: true,
   },
+  jobId: {
+    format: String,
+    default: null,
+    nullable: true,
+  },
+  owner: {
+    format: String,
+    default: null,
+    nullable: true,
+  },
+  repository: {
+    format: String,
+    default: null,
+    nullable: true,
+  },
 };
 
 export interface Config {
   apiBaseUrl: string;
   commit: string;
   branch: string | null;
-  token: string;
+  token: string | null;
   buildName: string | null;
   parallel: boolean;
   parallelNonce: string | null;
   parallelTotal: number | null;
+  owner: string | null;
+  repository: string | null;
+  jobId: string | null;
 }
 
 export const createConfig = () => {
diff --git a/packages/core/src/upload.ts b/packages/core/src/upload.ts
index 3b85cc3..9819938 100644
--- a/packages/core/src/upload.ts
+++ b/packages/core/src/upload.ts
@@ -4,7 +4,7 @@ import { getCiEnvironment } from "./ci-environment";
 import { discoverScreenshots } from "./discovery";
 import { optimizeScreenshot, getImageFormat } from "./optimize";
 import { hashFile } from "./hashing";
-import { createArgosApiClient } from "./api-client";
+import { createArgosApiClient, getBearerToken } from "./api-client";
 import { upload as uploadToS3 } from "./s3";
 import { debug } from "./debug";
 
@@ -61,6 +61,9 @@ const getConfigFromOptions = (options: UploadParameters) => {
           commit: ciEnv.commit,
           branch: ciEnv.branch,
           ciService: ciEnv.name,
+          owner: ciEnv.owner,
+          repository: ciEnv.repository,
+          jobId: ciEnv.jobId,
         })
       );
     }
@@ -79,6 +82,11 @@ export const upload = async (params: UploadParameters) => {
   const config = getConfigFromOptions(params);
   const files = params.files ?? ["**/*.{png,jpg,jpeg}"];
 
+  const apiClient = createArgosApiClient({
+    baseUrl: config.apiBaseUrl,
+    bearerToken: getBearerToken(config),
+  });
+
   // Collect screenshots
   const foundScreenshots = await discoverScreenshots(files, {
     root: params.root,
@@ -95,11 +103,6 @@ export const upload = async (params: UploadParameters) => {
     })
   );
 
-  const apiClient = createArgosApiClient({
-    baseUrl: config.apiBaseUrl,
-    token: config.token,
-  });
-
   // Create build
   debug("Creating build");
   const result = await apiClient.createBuild({