diff --git a/PluralKit.API/Controllers/MemberController.cs b/PluralKit.API/Controllers/MemberController.cs
new file mode 100644
index 00000000..e2d4b678
--- /dev/null
+++ b/PluralKit.API/Controllers/MemberController.cs
@@ -0,0 +1,66 @@
+using System.Data;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc;
+using PluralKit.Core;
+
+namespace PluralKit.API.Controllers
+{
+    [ApiController]
+    [Route("m")]
+    public class MemberController: ControllerBase
+    {
+        private MemberStore _members;
+        private IDbConnection _conn;
+        private TokenAuthService _auth;
+
+        public MemberController(MemberStore members, IDbConnection conn, TokenAuthService auth)
+        {
+            _members = members;
+            _conn = conn;
+            _auth = auth;
+        }
+
+        [HttpGet("{hid}")]
+        public async Task<ActionResult<PKMember>> GetMember(string hid)
+        {
+            var member = await _members.GetByHid(hid);
+            if (member == null) return NotFound("Member not found.");
+
+            return Ok(member);
+        }
+
+        [HttpPatch("{hid}")]
+        [RequiresSystem]
+        public async Task<ActionResult<PKMember>> PatchMember(string hid, [FromBody] PKMember newMember)
+        {
+            var member = await _members.GetByHid(hid);
+            if (member == null) return NotFound("Member not found.");
+
+            if (member.System != _auth.CurrentSystem.Id) return Unauthorized($"Member '{hid}' is not part of your system.");
+
+            // Explicit bounds checks
+            if (newMember.Name.Length > Limits.MaxMemberNameLength)
+                return BadRequest($"Member name too long ({newMember.Name.Length} > {Limits.MaxMemberNameLength}.");
+            if (newMember.Pronouns.Length > Limits.MaxPronounsLength)
+                return BadRequest($"Member pronouns too long ({newMember.Pronouns.Length} > {Limits.MaxPronounsLength}.");
+            if (newMember.Description.Length > Limits.MaxDescriptionLength)
+                return BadRequest($"Member descriptions too long ({newMember.Description.Length} > {Limits.MaxDescriptionLength}.");
+
+            // Sanity bounds checks
+            if (newMember.AvatarUrl.Length > 1000 || newMember.Prefix.Length > 1000 || newMember.Suffix.Length > 1000)
+                return BadRequest();
+
+            member.Name = newMember.Name;
+            member.Color = newMember.Color;
+            member.AvatarUrl = newMember.AvatarUrl;
+            member.Birthday = newMember.Birthday;
+            member.Pronouns = newMember.Pronouns;
+            member.Description = newMember.Description;
+            member.Prefix = newMember.Prefix;
+            member.Suffix = newMember.Suffix;
+            await _members.Save(member);
+            
+            return Ok();
+        }
+    }
+}
\ No newline at end of file
diff --git a/PluralKit.API/Controllers/SystemController.cs b/PluralKit.API/Controllers/SystemController.cs
index 73d1fb14..3cedf147 100644
--- a/PluralKit.API/Controllers/SystemController.cs
+++ b/PluralKit.API/Controllers/SystemController.cs
@@ -99,9 +99,9 @@ namespace PluralKit.API.Controllers
         }
 
         [HttpPatch]
+        [RequiresSystem]
         public async Task<ActionResult<PKSystem>> EditSystem([FromBody] PKSystem newSystem)
         {
-            if (_auth.CurrentSystem == null) return Unauthorized("No token specified in Authorization header.");
             var system = _auth.CurrentSystem;
             
             system.Name = newSystem.Name;
@@ -115,10 +115,9 @@ namespace PluralKit.API.Controllers
         }
 
         [HttpPost("switches")]
+        [RequiresSystem]
         public async Task<IActionResult> PostSwitch([FromBody] PostSwitchParams param)
         {
-            if (_auth.CurrentSystem == null) return Unauthorized("No token specified in Authorization header.");
-
             if (param.Members.Distinct().Count() != param.Members.Count())
                 return BadRequest("Duplicate members in member list.");
             
diff --git a/PluralKit.API/RequiresSystemAttribute.cs b/PluralKit.API/RequiresSystemAttribute.cs
new file mode 100644
index 00000000..381cf29e
--- /dev/null
+++ b/PluralKit.API/RequiresSystemAttribute.cs
@@ -0,0 +1,23 @@
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace PluralKit.API
+{
+    public class RequiresSystemAttribute: ActionFilterAttribute
+    {
+
+        public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
+        {
+            var auth = context.HttpContext.RequestServices.GetRequiredService<TokenAuthService>();
+            if (auth.CurrentSystem == null)
+            {
+                context.Result = new UnauthorizedObjectResult("Invalid or missing token in Authorization header.");
+                return;
+            }
+
+            await base.OnActionExecutionAsync(context, next);
+        }
+    }
+}
\ No newline at end of file
diff --git a/PluralKit.Bot/Commands/MemberCommands.cs b/PluralKit.Bot/Commands/MemberCommands.cs
index 968c5fc2..a2ad4867 100644
--- a/PluralKit.Bot/Commands/MemberCommands.cs
+++ b/PluralKit.Bot/Commands/MemberCommands.cs
@@ -6,6 +6,7 @@ using System.Threading.Tasks;
 using Discord;
 using Discord.Commands;
 using NodaTime;
+using PluralKit.Core;
 using Image = SixLabors.ImageSharp.Image;
 
 namespace PluralKit.Bot.Commands
diff --git a/PluralKit.Bot/Commands/SystemCommands.cs b/PluralKit.Bot/Commands/SystemCommands.cs
index 6a964324..477c02c3 100644
--- a/PluralKit.Bot/Commands/SystemCommands.cs
+++ b/PluralKit.Bot/Commands/SystemCommands.cs
@@ -9,6 +9,7 @@ using NodaTime;
 using NodaTime.Extensions;
 using NodaTime.Text;
 using NodaTime.TimeZones;
+using PluralKit.Core;
 
 namespace PluralKit.Bot.Commands
 {
diff --git a/PluralKit.Bot/Errors.cs b/PluralKit.Bot/Errors.cs
index 5cd76df9..6e346fe7 100644
--- a/PluralKit.Bot/Errors.cs
+++ b/PluralKit.Bot/Errors.cs
@@ -4,6 +4,7 @@ using System.Linq;
 using System.Net;
 using Humanizer;
 using NodaTime;
+using PluralKit.Core;
 
 namespace PluralKit.Bot {
     public static class Errors {
diff --git a/PluralKit.Bot/Utils.cs b/PluralKit.Bot/Utils.cs
index e1fc6531..f55458ed 100644
--- a/PluralKit.Bot/Utils.cs
+++ b/PluralKit.Bot/Utils.cs
@@ -12,6 +12,7 @@ using Discord.Commands.Builders;
 using Discord.WebSocket;
 using Microsoft.Extensions.DependencyInjection;
 using NodaTime;
+using PluralKit.Core;
 using Image = SixLabors.ImageSharp.Image;
 
 namespace PluralKit.Bot
diff --git a/PluralKit.Bot/Limits.cs b/PluralKit.Core/Limits.cs
similarity index 94%
rename from PluralKit.Bot/Limits.cs
rename to PluralKit.Core/Limits.cs
index 3f7b3ec5..37f56ea7 100644
--- a/PluralKit.Bot/Limits.cs
+++ b/PluralKit.Core/Limits.cs
@@ -1,4 +1,4 @@
-namespace PluralKit.Bot {
+namespace PluralKit.Core {
     public static class Limits {
         public static readonly int MaxSystemNameLength = 100;
         public static readonly int MaxSystemTagLength = 31;