diff --git a/alchemiscale_fah/compute/client.py b/alchemiscale_fah/compute/client.py
index e69de29..5e33942 100644
--- a/alchemiscale_fah/compute/client.py
+++ b/alchemiscale_fah/compute/client.py
@@ -0,0 +1,215 @@
+#!/usr/bin/env python3
+
+import os
+import requests
+from typing import Optional
+from urllib.parse import urljoin
+
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import rsa
+from cryptography.hazmat.backends import default_backend
+from cryptography import x509
+from cryptography.x509.oid import NameOID
+from cryptography.hazmat.primitives import hashes
+
+
+# project_data = dict(
+#    core_id=0x22,
+#    gens=25000,
+#    atoms=288449,
+#    credit=56,
+#    timeout=0.002,
+#    deadline=0.005,
+# )
+
+
+class FahAdaptiveSamplingClient:
+    def __init__(
+        self,
+        as_api_url: str,
+        ws_api_url: str,
+        ws_ip_addr: str,
+        certificate_file: os.PathLike = "api-certificate.pem",
+        key_file: os.PathLike = "api-private.pem",
+        verify: bool = True,
+    ):
+        self.as_api_url = as_api_url
+        self.ws_api_url = ws_api_url
+        self.ws_ip_addr = ws_ip_addr
+
+        self.certificate = self.read_certificate(certificate_file)
+
+        if key_file is None:
+            self.key = self.create_key()
+        else:
+            self.key = self.read_key(key_file)
+
+        self.verify = verify
+
+    @staticmethod
+    def read_key(key_file):
+        with open(key_file, "rb") as f:
+            pem = f.read()
+
+        return serialization.load_pem_private_key(pem, None, default_backend())
+
+    @staticmethod
+    def read_certificate(certificate_file):
+        with open(certificate_file, "rb") as f:
+            pem = f.read()
+
+        return x509.load_pem_x509_certificate(pem, default_backend())
+
+    @classmethod
+    def create_key():
+        return rsa.generate_private_key(
+            backend=default_backend(), public_exponent=65537, key_size=4096
+        )
+
+    @classmethod
+    def write_key(key, key_file):
+        pem = key.private_bytes(
+            encoding=serialization.Encoding.PEM,
+            format=serialization.PrivateFormat.TraditionalOpenSSL,
+            encryption_algorithm=serialization.NoEncryption(),
+        )
+
+        with open(key_file, "wb") as f:
+            f.write(pem)
+
+    @classmethod
+    def generate_csr(key, csr_file):
+        """Generate certificate signing request (CSR) using private key.
+
+        It is necessary to create a CSR and present this to an AS in order to
+        receive a valid certificate. The CSR will be written in PEM format.
+
+        """
+        cn = x509.NameAttribute(NameOID.COMMON_NAME, "joe@example.com")
+        csr = x509.CertificateSigningRequestBuilder()
+        csr = csr.subject_name(x509.Name([cn]))
+        csr = csr.sign(key, hashes.SHA256())
+
+        with open(csr_file, "wb") as f:
+            f.write(csr.public_bytes(serialization.Encoding.PEM))
+
+    def _check_status(self, r):
+        if r.status_code != 200:
+            raise Exception("Request failed with %d: %s" % (r.status_code, r.text))
+
+    def _get(self, api_url, endpoint, **params):
+        url = urljoin(api_url, endpoint)
+        r = requests.get(url, cert=self.cert, params=params, verify=self.verify)
+        self._check_status(r)
+        return r.json()
+
+    def _put(self, api_url, endpoint, **data):
+        url = urljoin(api_url, endpoint)
+        r = requests.put(url, json=data, cert=self.cert, verify=self.verify)
+        self._check_status(r)
+
+    def _delete(self, api_url, endpoint):
+        url = urljoin(api_url, endpoint)
+        r = requests.delete(url, cert=self.cert, verify=self.verify)
+        self._check_status(r)
+
+    def _upload(self, api_url, endpoint, filename):
+        url = urljoin(api_url, endpoint)
+        with open(filename, "rb") as f:
+            r = requests.put(url, data=f, cert=self.cert, verify=self.verify)
+            self._check_status(r)
+
+    def _download(self, api_url, endpoint, filename):
+        url = urljoin(api_url, endpoint)
+        r = requests.get(url, cert=self.cert, verify=self.verify, stream=True)
+        self._check_status(r)
+
+        os.makedirs(os.path.dirname(filename), exist_ok=True)
+
+        with open(filename, "wb") as f:
+            for chunk in r.iter_content(chunk_size=8192):
+                f.write(chunk)
+
+        r.close()
+
+    def as_get_ws(self):
+        """Get work server attributes from assignment server."""
+        return self._get(self.as_api_url, f"/ws/{self.ws_ip_addr}")
+
+    def as_set_ws(self, as_workserver_data):
+        """Set work server attributes on assignment server."""
+        return self._put(
+            self.as_api_url, f"/ws/{self.ws_ip_addr}", **as_workserver_data
+        )
+
+    def as_get_project(self, project_id):
+        """Set project attributes on the assignment server."""
+        self._gut(
+            self.as_api_url,
+            f"/ws/{self.ws_ip_addr}/projects/{project_id}",
+        )
+
+    def as_set_project(self, project_id, weight, constraints):
+        """Set project attributes on the assignment server."""
+        self._put(
+            self.as_api_url,
+            f"/ws/{self.ws_ip_addr}/projects/{project_id}",
+            weight=weight,
+            constraints=constraints,
+        )
+
+    def as_reset_project(self, project_id):
+        """Set project attributes to default on the assignment server.
+
+        Sets project weight to 0, drops all constraints.
+
+        """
+        self._put(
+            self.as_api_url,
+            f"/ws/{self.ws_ip_addr}/projects/{project_id}",
+            weight=0,
+            constraints="",
+        )
+
+    def create_project(self, project_id, project_data):
+        self._put(self.ws_api_url, f"/projects/{project_id}", **project_data)
+
+    def delete_project(self, project_id):
+        self._delete(self.ws_api_url, f"/projects/{project_id}")
+
+    def start_run(self, project_id, run_id, clones=0):
+        """Start a new run."""
+        self._put(
+            self.ws_api_url,
+            f"/projects/{project_id}/runs/{run_id}/create",
+            clones=clones,
+        )
+
+    def upload_project_files(self, project_id):
+        files = "core.xml integrator.xml.bz2 state.xml.bz2 system.xml.bz2".split()
+
+        for name in files:
+            self._upload(self.ws_api_url, f"/projects/{project_id}/files/{name}", name)
+
+    def get_project(self, project_id):
+        return self._get(self.ws_api_url, f"/projects/{project_id}")
+
+    def get_job_files(self, project_id, run_id, clone_id):
+        return self._get(
+            self.ws_api_url,
+            f"/projects/{project_id}/runs/{run_id}/clones/{clone_id}/files",
+        )
+
+    def get_xtcs(self, project_id, run_id, clone_id):
+        data = self._get(
+            self.ws_api_url,
+            f"/projects/{project_id}/runs/{run_id}/clones/{clone_id}/files",
+        )
+
+        for info in data:
+            if info["path"].endswith(".xtc"):
+                self._download(
+                    self.ws_api_url,
+                    f"/projects/{project_id}/runs/{run_id}/clones/{clone_id}/files/{info['path']}",
+                    info["path"],
+                )
diff --git a/alchemiscale_fah/compute/service.py b/alchemiscale_fah/compute/service.py
index aa55571..f798be5 100644
--- a/alchemiscale_fah/compute/service.py
+++ b/alchemiscale_fah/compute/service.py
@@ -3,7 +3,88 @@
 ===============================================================================================
 
 """
+import os
+from typing import Union, Optional, List, Dict, Tuple
+from pathlib import Path
+from uuid import uuid4
+import time
+import logging
 
+from alchemiscale.models import Scope, ScopedKey
+from alchemiscale.storage.models import Task, TaskHub, ComputeServiceID
+from alchemiscale.compute.client import AlchemiscaleComputeClient
+from alchemiscale.compute.service import SynchronousComputeService, InterruptableSleep
 
-class FAHComputeService:
-    ...
+from .settings import FAHSynchronousComputeServiceSettings
+from .client import FahWorkServerClient
+
+
+class FahSynchronousComputeService(SynchronousComputeService):
+    """Fully synchronous compute service for utilizing a Folding@Home work server.
+
+    This service is intended for use as a reference implementation, and for
+    testing/debugging protocols.
+
+    """
+
+    def __init__(self, settings: FAHSynchronousComputeServiceSettings):
+        """Create a `FAHSynchronousComputeService` instance."""
+        self.settings = settings
+
+        self.api_url = self.settings.api_url
+        self.name = self.settings.name
+        self.sleep_interval = self.settings.sleep_interval
+        self.heartbeat_interval = self.settings.heartbeat_interval
+        self.claim_limit = self.settings.claim_limit
+
+        self.client = AlchemiscaleComputeClient(
+            self.settings.api_url,
+            self.settings.identifier,
+            self.settings.key,
+            max_retries=self.settings.client_max_retries,
+            retry_base_seconds=self.settings.client_retry_base_seconds,
+            retry_max_seconds=self.settings.client_retry_max_seconds,
+            verify=self.settings.client_verify,
+        )
+
+        self.fah_client = FahWorkServerClient(...)
+
+        if self.settings.scopes is None:
+            self.scopes = [Scope()]
+        else:
+            self.scopes = self.settings.scopes
+
+        self.shared_basedir = Path(self.settings.shared_basedir).absolute()
+        self.shared_basedir.mkdir(exist_ok=True)
+        self.keep_shared = self.settings.keep_shared
+
+        self.scratch_basedir = Path(self.settings.scratch_basedir).absolute()
+        self.scratch_basedir.mkdir(exist_ok=True)
+        self.keep_scratch = self.settings.keep_scratch
+
+        self.compute_service_id = ComputeServiceID(f"{self.name}-{uuid4()}")
+
+        self.int_sleep = InterruptableSleep()
+
+        self._stop = False
+
+        # logging
+        extra = {"compute_service_id": str(self.compute_service_id)}
+        logger = logging.getLogger("AlchemiscaleSynchronousComputeService")
+        logger.setLevel(self.settings.loglevel)
+
+        formatter = logging.Formatter(
+            "[%(asctime)s] [%(compute_service_id)s] [%(levelname)s] %(message)s"
+        )
+        formatter.converter = time.gmtime  # use utc time for logging timestamps
+
+        sh = logging.StreamHandler()
+        sh.setFormatter(formatter)
+        logger.addHandler(sh)
+
+        if self.settings.logfile is not None:
+            fh = logging.FileHandler(self.settings.logfile)
+            fh.setFormatter(formatter)
+            logger.addHandler(fh)
+
+        self.logger = logging.LoggerAdapter(logger, extra)
diff --git a/alchemiscale_fah/compute/settings.py b/alchemiscale_fah/compute/settings.py
new file mode 100644
index 0000000..0370e1e
--- /dev/null
+++ b/alchemiscale_fah/compute/settings.py
@@ -0,0 +1,80 @@
+import os
+from typing import Union, Optional, List, Dict, Tuple
+from pydantic import BaseModel
+
+from alchemiscale.models import Scope, ScopedKey
+
+
+class FAHSynchronousComputeServiceSettings(BaseModel):
+    api_url: str
+    identifier: str
+    key: str
+    name: str
+    shared_basedir: os.PathLike
+    scratch_basedir: os.PathLike
+    keep_shared: bool = False
+    keep_scratch: bool = False
+    sleep_interval: int = 30
+    heartbeat_interval: int = 300
+    scopes: Optional[List[Scope]] = None
+    claim_limit: int = 1
+    loglevel = "WARN"
+    logfile: Optional[os.PathLike] = None
+    client_max_retries = (5,)
+    client_retry_base_seconds = 2.0
+    client_retry_max_seconds = 60.0
+    client_verify = True
+
+
+"""
+        Parameters
+        ----------
+        api_url
+            URL of the compute API to execute Tasks for.
+        identifier
+            Identifier for the compute identity used for authentication.
+        key
+            Credential for the compute identity used for authentication.
+        name
+            The name to give this compute service; used for Task provenance, so
+            typically set to a distinct value to distinguish different compute
+            resources, e.g. different hosts or HPC clusters.
+        shared_basedir
+            Filesystem path to use for `ProtocolDAG` `shared` space.
+        scratch_basedir
+            Filesystem path to use for `ProtocolUnit` `scratch` space.
+        keep_shared
+            If True, don't remove shared directories for `ProtocolDAG`s after
+            completion.
+        keep_scratch
+            If True, don't remove scratch directories for `ProtocolUnit`s after
+            completion.
+        sleep_interval
+            Time in seconds to sleep if no Tasks claimed from compute API.
+        heartbeat_interval
+            Frequency at which to send heartbeats to compute API.
+        scopes
+            Scopes to limit Task claiming to; defaults to all Scopes accessible
+            by compute identity.
+        claim_limit
+            Maximum number of Tasks to claim at a time from a TaskHub.
+        loglevel
+            The loglevel at which to report; see the :mod:`logging` docs for
+            available levels.
+        logfile
+            Path to file for logging output; if not set, logging will only go
+            to STDOUT.
+        client_max_retries
+            Maximum number of times to retry a request. In the case the API
+            service is unresponsive an expoenential backoff is applied with
+            retries until this number is reached. If set to -1, retries will
+            continue indefinitely until success.
+        client_retry_base_seconds
+            The base number of seconds to use for exponential backoff.
+            Must be greater than 1.0.
+        client_retry_max_seconds
+            Maximum number of seconds to sleep between retries; avoids runaway
+            exponential backoff while allowing for many retries.
+        client_verify
+            Whether to verify SSL certificate presented by the API server.
+"""