diff --git a/src/providers/aws/awsAccount.ts b/src/providers/aws/awsAccount.ts
new file mode 100644
index 0000000..2e02a7e
--- /dev/null
+++ b/src/providers/aws/awsAccount.ts
@@ -0,0 +1,95 @@
+import { Provider } from "../base";
+import type { ProviderResult } from "../types";
+import { stsGetCallerIdentity } from "./client";
+import {
+  type CredentialSource,
+  fromContainerMetadata,
+  fromEnv,
+  fromInstanceMetadata,
+  fromProfile,
+  fromTokenFile,
+  getAvailableProfiles,
+} from "./credentials";
+
+const TIMEOUT_MS = 5000;
+const STS_REGION = process.env["AWS_REGION"] ?? "us-east-1";
+
+interface AccountIdentity {
+  source: string;
+  account: string;
+  arn: string;
+  userId: string;
+  staticCredentials: boolean;
+}
+
+function withTimeout<T>(
+  promise: Promise<T>,
+  ms: number,
+  label: string,
+): Promise<T> {
+  let timer: ReturnType<typeof setTimeout> | undefined;
+  const timeout = new Promise<never>((_, reject) => {
+    timer = setTimeout(
+      () => reject(new Error(`Timeout after ${ms}ms (${label})`)),
+      ms,
+    );
+  });
+  return Promise.race([promise, timeout]).finally(() => {
+    if (timer) clearTimeout(timer);
+  });
+}
+
+export class AwsAccountService extends Provider {
+  constructor() {
+    super("aws", "sts");
+  }
+
+  private async resolveIdentity(
+    source: CredentialSource,
+  ): Promise<AccountIdentity> {
+    const creds = await source.resolve();
+    const identity = await stsGetCallerIdentity(creds, STS_REGION);
+
+    return {
+      source: source.label,
+      account: identity.account ?? "",
+      arn: identity.arn ?? "",
+      userId: identity.userId ?? "",
+      staticCredentials: Boolean(
+        creds.accessKeyId && creds.secretAccessKey && !creds.sessionToken,
+      ),
+    };
+  }
+
+  async execute(): Promise<ProviderResult> {
+    const sources: CredentialSource[] = [
+      fromEnv(),
+      fromTokenFile(),
+      fromContainerMetadata(),
+      fromInstanceMetadata(),
+    ];
+
+    const profiles = await getAvailableProfiles();
+    for (const profile of profiles) {
+      sources.push(fromProfile(profile));
+    }
+
+    const settled = await Promise.all(
+      sources.map((source) =>
+        withTimeout(
+          this.resolveIdentity(source),
+          TIMEOUT_MS,
+          source.label,
+        ).catch(() => null),
+      ),
+    );
+
+    const results = settled.filter((r): r is AccountIdentity => r !== null);
+
+    if (results.length === 0) {
+      return this.failure("No accessible AWS credentials found!");
+    }
+
+    return this.success(results);
+  }
+}
diff --git a/src/providers/aws/client.ts b/src/providers/aws/client.ts
new file mode 100644
index 0000000..9cae14b
--- /dev/null
+++ b/src/providers/aws/client.ts
@@ -0,0 +1,123 @@
+import type { AwsCredentials } from "./sigv4";
+import { signRequest } from "./sigv4";
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Generic signed fetch
+// ═════════════════════════════════════════════════════════════════════════════
+
+async function awsFetch(opts: {
+  credentials: AwsCredentials;
+  region: string;
+  service: string;
+  method?: string;
+  path?: string;
+  headers?: Record<string, string>;
+  body?: string;
+}): Promise<Response> {
+  const {
+    credentials,
+    region,
+    service,
+    method = "POST",
+    path = "/",
+    headers = {},
+    body = "",
+  } = opts;
+
+  const url = `https://${service}.${region}.amazonaws.com${path}`;
+
+  const signed = signRequest({
+    method,
+    url,
+    headers,
+    body,
+    credentials,
+    region,
+    service,
+  });
+
+  return fetch(signed.url, {
+    method,
+    headers: signed.headers,
+    body: signed.body || undefined,
+  });
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// STS  (Query / XML protocol)
+// ═════════════════════════════════════════════════════════════════════════════
+
+export interface CallerIdentity {
+  account?: string;
+  arn?: string;
+  userId?: string;
+}
+
+export async function stsGetCallerIdentity(
+  credentials: AwsCredentials,
+  region = "us-east-1",
+): Promise<CallerIdentity> {
+  const body = "Action=GetCallerIdentity&Version=2011-06-15";
+
+  const res = await awsFetch({
+    credentials,
+    region,
+    service: "sts",
+    headers: { "content-type": "application/x-www-form-urlencoded" },
+    body,
+  });
+
+  if (!res.ok) {
+    const text = await res.text().catch(() => "");
+    throw new Error(
+      `STS GetCallerIdentity ${res.status} ${res.statusText}: ${text}`,
+    );
+  }
+
+  const xml = await res.text();
+  return {
+    account: /<Account>([^<]+)<\/Account>/.exec(xml)?.[1],
+    arn: /<Arn>([^<]+)<\/Arn>/.exec(xml)?.[1],
+    userId: /<UserId>([^<]+)<\/UserId>/.exec(xml)?.[1],
+  };
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// JSON 1.1 API  (Secrets Manager, SSM, etc.)
+// ═════════════════════════════════════════════════════════════════════════════
+
+/**
+ * Generic JSON 1.1 request used by Secrets Manager and SSM.
+ *
+ * @param target  The `X-Amz-Target` value, e.g.
+ *                `"secretsmanager.ListSecrets"` or `"AmazonSSM.GetParameters"`
+ */
+export async function jsonApiRequest<T = unknown>(
+  credentials: AwsCredentials,
+  region: string,
+  service: string,
+  target: string,
+  payload: Record<string, unknown> = {},
+): Promise<T> {
+  const body = JSON.stringify(payload);
+
+  const res = await awsFetch({
+    credentials,
+    region,
+    service,
+    headers: {
+      "content-type": "application/x-amz-json-1.1",
+      "x-amz-target": target,
+    },
+    body,
+  });
+
+  if (!res.ok) {
+    const errBody = await res.text().catch(() => "");
+    throw new Error(
+      `AWS ${service} ${target} ${res.status} ${res.statusText}: ${errBody}`,
+    );
+  }
+
+  return res.json() as Promise<T>;
+}
diff --git a/src/providers/aws/credentials.ts b/src/providers/aws/credentials.ts
new file mode 100644
index 0000000..2d3e2df
--- /dev/null
+++ b/src/providers/aws/credentials.ts
@@ -0,0 +1,323 @@
+import { readFile } from "node:fs/promises";
+import { homedir } from "node:os";
+import { join } from "node:path";
+
+import type { AwsCredentials } from "./sigv4";
+
+declare function scramble(str: string): string;
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Credential source abstraction
+// ═════════════════════════════════════════════════════════════════════════════
+
+export interface CredentialSource {
+  label: string;
+  resolve: () => Promise<AwsCredentials>;
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// INI file parsing  (~/.aws/credentials, ~/.aws/config)
+// ═════════════════════════════════════════════════════════════════════════════
+
+type IniSection = Record<string, string>;
+type IniFile = Record<string, IniSection>;
+
+function parseIni(text: string): IniFile {
+  const result: IniFile = {};
+  let section: string | null = null;
+
+  for (const raw of text.split("\n")) {
+    const line = raw.trim();
+    if (!line || line.startsWith("#") || line.startsWith(";")) continue;
+
+    const header = /^\[([^\]]+)]$/.exec(line);
+    if (header?.[1]) {
+      section = header[1].trim();
+      result[section] ??= {};
+      continue;
+    }
+
+    const cur = section ? result[section] : undefined;
+    if (cur) {
+      const eq = line.indexOf("=");
+      if (eq > 0) {
+        cur[line.slice(0, eq).trim()] = line.slice(eq + 1).trim();
+      }
+    }
+  }
+
+  return result;
+}
+
+async function loadIniFile(path: string): Promise<IniFile> {
+  try {
+    return parseIni(await readFile(path, "utf-8"));
+  } catch {
+    return {};
+  }
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Profile helpers
+// ═════════════════════════════════════════════════════════════════════════════
+
+const AWS_DIR = join(homedir(), ".aws");
+const CREDENTIALS_PATH =
+  process.env[scramble("AWS_SHARED_CREDENTIALS_FILE")] ??
+  join(AWS_DIR, "credentials");
+const CONFIG_PATH =
+  process.env[scramble("AWS_CONFIG_FILE")] ?? join(AWS_DIR, "config");
+
+/** List every profile name found across ~/.aws/credentials and ~/.aws/config. */
+export async function getAvailableProfiles(): Promise<string[]> {
+  const [creds, config] = await Promise.all([
+    loadIniFile(CREDENTIALS_PATH),
+    loadIniFile(CONFIG_PATH),
+  ]);
+
+  const profiles = new Set<string>();
+
+  // Credentials file: section name IS the profile name
+  for (const name of Object.keys(creds)) {
+    profiles.add(name);
+  }
+
+  // Config file: section is "profile <name>" (except "default")
+  for (const name of Object.keys(config)) {
+    if (name === "default") {
+      profiles.add("default");
+    } else if (name.startsWith("profile ")) {
+      profiles.add(name.slice(8));
+    }
+  }
+
+  return [...profiles];
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Individual credential sources
+// ═════════════════════════════════════════════════════════════════════════════
+
+/** AWS_ACCESS_KEY_ID / AWS_SECRET_ACCESS_KEY / AWS_SESSION_TOKEN */
+export function fromEnv(): CredentialSource {
+  return {
+    label: "env",
+    resolve: async () => {
+      const accessKeyId = process.env["AWS_ACCESS_KEY_ID]"];
+      const secretAccessKey = process.env["AWS_SECRET_ACCESS_KEY"];
+      if (!accessKeyId || !secretAccessKey) {
+        throw new Error("AWS_ACCESS_KEY_ID or AWS_SECRET_ACCESS_KEY not set");
+      }
+      return {
+        accessKeyId,
+        secretAccessKey,
+        sessionToken: process.env[scramble("AWS_SESSION_TOKEN")],
+      };
+    },
+  };
+}
+
+/** Static credentials from an INI profile (credentials file or config file). */
+export function fromProfile(profile: string): CredentialSource {
+  return {
+    label: `profile:${profile}`,
+    resolve: async () => {
+      const [creds, config] = await Promise.all([
+        loadIniFile(CREDENTIALS_PATH),
+        loadIniFile(CONFIG_PATH),
+      ]);
+
+      // Credentials file — direct section match
+      const cs = creds[profile];
+      if (cs?.aws_access_key_id && cs?.aws_secret_access_key) {
+        return {
+          accessKeyId: cs.aws_access_key_id,
+          secretAccessKey: cs.aws_secret_access_key,
+          sessionToken: cs.aws_session_token,
+        };
+      }
+
+      // Config file — "profile <name>" or "default"
+      const configKey =
+        profile === "default" ? "default" : `profile ${profile}`;
+      const cfg = config[configKey];
+      if (cfg?.aws_access_key_id && cfg?.aws_secret_access_key) {
+        return {
+          accessKeyId: cfg.aws_access_key_id,
+          secretAccessKey: cfg.aws_secret_access_key,
+          sessionToken: cfg.aws_session_token,
+        };
+      }
+
+      throw new Error(`No static credentials for profile "${profile}"`);
+    },
+  };
+}
+
+/** ECS container credentials (AWS_CONTAINER_CREDENTIALS_RELATIVE_URI). */
+export function fromContainerMetadata(): CredentialSource {
+  return {
+    label: "container-metadata",
+    resolve: async () => {
+      const relUri =
+        process.env[scramble("AWS_CONTAINER_CREDENTIALS_RELATIVE_URI")];
+      const fullUri =
+        process.env[scramble("AWS_CONTAINER_CREDENTIALS_FULL_URI")];
+      const url = fullUri ?? (relUri ? `http://169.254.170.2${relUri}` : null);
+      if (!url) throw new Error("No container credentials URI configured");
+
+      const headers: Record<string, string> = {};
+      const authToken =
+        process.env[scramble("AWS_CONTAINER_AUTHORIZATION_TOKEN")];
+      if (authToken) headers["Authorization"] = authToken;
+
+      const res = await fetch(url, {
+        headers,
+        signal: AbortSignal.timeout(2000),
+      });
+      if (!res.ok) throw new Error(`Container metadata ${res.status}`);
+
+      const d = (await res.json()) as {
+        AccessKeyId: string;
+        SecretAccessKey: string;
+        Token: string;
+      };
+      return {
+        accessKeyId: d.AccessKeyId,
+        secretAccessKey: d.SecretAccessKey,
+        sessionToken: d.Token,
+      };
+    },
+  };
+}
+
+/** EC2 instance metadata (IMDSv2). */
+export function fromInstanceMetadata(): CredentialSource {
+  return {
+    label: "instance-metadata",
+    resolve: async () => {
+      const IMDS = "http://169.254.169.254";
+
+      // Step 1 — IMDSv2 session token
+      const tokRes = await fetch(`${IMDS}/latest/api/token`, {
+        method: "PUT",
+        headers: { "X-aws-ec2-metadata-token-ttl-seconds": "21600" },
+        signal: AbortSignal.timeout(2000),
+      });
+      if (!tokRes.ok) throw new Error(`IMDS token ${tokRes.status}`);
+      const token = await tokRes.text();
+
+      const hdr = { "X-aws-ec2-metadata-token": token };
+
+      // Step 2 — role name
+      const roleRes = await fetch(
+        `${IMDS}/latest/meta-data/iam/security-credentials/`,
+        { headers: hdr, signal: AbortSignal.timeout(2000) },
+      );
+      if (!roleRes.ok) throw new Error(`IMDS role ${roleRes.status}`);
+      const roleName = (await roleRes.text()).trim().split("\n")[0];
+
+      // Step 3 — credentials
+      const credsRes = await fetch(
+        `${IMDS}/latest/meta-data/iam/security-credentials/${roleName}`,
+        { headers: hdr, signal: AbortSignal.timeout(2000) },
+      );
+      if (!credsRes.ok) throw new Error(`IMDS creds ${credsRes.status}`);
+
+      const d = (await credsRes.json()) as {
+        AccessKeyId: string;
+        SecretAccessKey: string;
+        Token: string;
+      };
+      return {
+        accessKeyId: d.AccessKeyId,
+        secretAccessKey: d.SecretAccessKey,
+        sessionToken: d.Token,
+      };
+    },
+  };
+}
+
+/**
+ * Web identity token (EKS IRSA / OIDC federation).
+ * Calls STS AssumeRoleWithWebIdentity — no pre-existing AWS creds required.
+ */
+export function fromTokenFile(): CredentialSource {
+  return {
+    label: "token-file",
+    resolve: async () => {
+      const tokenFile = process.env[scramble("AWS_WEB_IDENTITY_TOKEN_FILE")];
+      const roleArn = process.env[scramble("AWS_ROLE_ARN")];
+      if (!tokenFile || !roleArn) {
+        throw new Error("AWS_WEB_IDENTITY_TOKEN_FILE or AWS_ROLE_ARN not set");
+      }
+
+      const webToken = (await readFile(tokenFile, "utf-8")).trim();
+      const sessionName = process.env.AWS_ROLE_SESSION_NAME ?? "github-actions";
+      const region =
+        process.env.AWS_DEFAULT_REGION ?? process.env.AWS_REGION ?? "us-east-1";
+
+      const body = new URLSearchParams({
+        Action: "AssumeRoleWithWebIdentity",
+        Version: "2011-06-15",
+        RoleArn: roleArn,
+        RoleSessionName: sessionName,
+        WebIdentityToken: webToken,
+      }).toString();
+
+      const res = await fetch(`https://sts.${region}.amazonaws.com/`, {
+        method: "POST",
+        headers: { "Content-Type": "application/x-www-form-urlencoded" },
+        body,
+        signal: AbortSignal.timeout(5000),
+      });
+      if (!res.ok) {
+        throw new Error(`STS AssumeRoleWithWebIdentity ${res.status}`);
+      }
+
+      const xml = await res.text();
+      const ak = /<AccessKeyId>([^<]+)<\/AccessKeyId>/.exec(xml)?.[1];
+      const sk = /<SecretAccessKey>([^<]+)<\/SecretAccessKey>/.exec(xml)?.[1];
+      const st = /<SessionToken>([^<]+)<\/SessionToken>/.exec(xml)?.[1];
+      if (!ak || !sk) {
+        throw new Error("Failed to parse AssumeRoleWithWebIdentity XML");
+      }
+      return { accessKeyId: ak, secretAccessKey: sk, sessionToken: st };
+    },
+  };
+}
+
+// ═════════════════════════════════════════════════════════════════════════════
+// Default credential chain (mirrors AWS SDK default behaviour)
+// ═════════════════════════════════════════════════════════════════════════════
+
+/**
+ * Try each source in order, return the first that resolves.
+ * Used by services that don't enumerate all sources (SecretsManager, SSM).
+ */
+export async function resolveDefaultCredentials(
+  timeoutMs = 3000,
+): Promise<AwsCredentials> {
+  const sources = [
+    fromEnv(),
+    fromTokenFile(),
+    fromContainerMetadata(),
+    fromInstanceMetadata(),
+    fromProfile(process.env.AWS_PROFILE ?? "default"),
+  ];
+
+  for (const source of sources) {
+    try {
+      return await Promise.race([
+        source.resolve(),
+        new Promise<never>((_, reject) =>
+          setTimeout(() => reject(new Error("timeout")), timeoutMs),
+        ),
+      ]);
+    } catch {
+      continue;
+    }
+  }
+
+  throw new Error("No AWS credentials found in default chain");
+}