diff --git a/package-lock.json b/package-lock.json
index d7bc4fd40..b4e05ee83 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,7 +8,7 @@
         "@snowpack/plugin-typescript": "^1.2.1",
         "ethers": "^5.0.31",
         "svelte": "^3.32.3",
-        "svelte-routing": "^1.5.0"
+        "svelte-routing": "^1.6.0"
       },
       "devDependencies": {
         "@snowpack/plugin-svelte": "^3.5.2",
@@ -852,6 +852,11 @@
         "node": ">= 8"
       }
     },
+    "node_modules/dedent-js": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dedent-js/-/dedent-js-1.0.1.tgz",
+      "integrity": "sha1-vuX7fJ5yfYXf+iRZDRDsGrElUwU="
+    },
     "node_modules/detect-indent": {
       "version": "6.0.0",
       "dev": true,
@@ -1148,6 +1153,14 @@
       "version": "0.5.7",
       "license": "MIT"
     },
+    "node_modules/lower-case": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/lower-case/-/lower-case-2.0.2.tgz",
+      "integrity": "sha512-7fm3l3NAF9WfN6W3JOmf5drwpVqX78JtoGJ3A6W0a6ZnldM41w2fV5D490psKFTpMds8TJse/eHLFFsNHHjHgg==",
+      "dependencies": {
+        "tslib": "^2.0.3"
+      }
+    },
     "node_modules/merge-stream": {
       "version": "2.0.0",
       "license": "MIT"
@@ -1191,6 +1204,15 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/no-case": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/no-case/-/no-case-3.0.4.tgz",
+      "integrity": "sha512-fgAN3jGAh+RoxUGZHTSOLJIqUc2wmoBwGR4tbpNAKmmovFoWq0OdRkb0VkldReO2a2iBT/OEulG9XSUc10r3zg==",
+      "dependencies": {
+        "lower-case": "^2.0.2",
+        "tslib": "^2.0.3"
+      }
+    },
     "node_modules/normalize-path": {
       "version": "3.0.0",
       "dev": true,
@@ -1256,6 +1278,15 @@
         "node": ">=6"
       }
     },
+    "node_modules/pascal-case": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/pascal-case/-/pascal-case-3.1.2.tgz",
+      "integrity": "sha512-uWlGT3YSnK9x3BQJaOdcZwrnV6hPpd8jFH1/ucpiLRPh/2zCVJKS19E4GvYHvaCcACn3foXZ0cLB9Wrx1KGe5g==",
+      "dependencies": {
+        "no-case": "^3.0.4",
+        "tslib": "^2.0.3"
+      }
+    },
     "node_modules/path-is-absolute": {
       "version": "1.0.1",
       "dev": true,
@@ -1527,12 +1558,29 @@
       }
     },
     "node_modules/svelte-routing": {
-      "version": "1.5.0",
-      "license": "MIT",
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/svelte-routing/-/svelte-routing-1.6.0.tgz",
+      "integrity": "sha512-+DbrSGttLA6lan7oWFz1MjyGabdn3tPRqn8Osyc471ut2UgCrzM5x1qViNMc2gahOP6fKbKK1aNtZMJEQP2vHQ==",
+      "dependencies": {
+        "svelte2tsx": "^0.1.157"
+      },
       "peerDependencies": {
         "svelte": "^3.20.x"
       }
     },
+    "node_modules/svelte2tsx": {
+      "version": "0.1.189",
+      "resolved": "https://registry.npmjs.org/svelte2tsx/-/svelte2tsx-0.1.189.tgz",
+      "integrity": "sha512-Mo4Sei1tNYthzSZx6biGSK7pI6/vj7nGvvmSevmLIiws/o1hyj1UIHn+AwqogeA9L46fcvy6WU3t7HxDg+LbLg==",
+      "dependencies": {
+        "dedent-js": "^1.0.1",
+        "pascal-case": "^3.1.1"
+      },
+      "peerDependencies": {
+        "svelte": "^3.24",
+        "typescript": "^4.1.2"
+      }
+    },
     "node_modules/to-regex-range": {
       "version": "5.0.1",
       "dev": true,
@@ -1544,6 +1592,11 @@
         "node": ">=8.0"
       }
     },
+    "node_modules/tslib": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.2.0.tgz",
+      "integrity": "sha512-gS9GVHRU+RGn5KQM2rllAlR3dU6m7AcpJKdtH8gFvQiC4Otgk98XnmMU+nZenHt/+VhnBPWwgrJsyrdcw6i23w=="
+    },
     "node_modules/typescript": {
       "version": "4.2.4",
       "license": "Apache-2.0",
@@ -2033,6 +2086,11 @@
         "which": "^2.0.1"
       }
     },
+    "dedent-js": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dedent-js/-/dedent-js-1.0.1.tgz",
+      "integrity": "sha1-vuX7fJ5yfYXf+iRZDRDsGrElUwU="
+    },
     "detect-indent": {
       "version": "6.0.0",
       "dev": true
@@ -2222,6 +2280,14 @@
     "js-sha3": {
       "version": "0.5.7"
     },
+    "lower-case": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/lower-case/-/lower-case-2.0.2.tgz",
+      "integrity": "sha512-7fm3l3NAF9WfN6W3JOmf5drwpVqX78JtoGJ3A6W0a6ZnldM41w2fV5D490psKFTpMds8TJse/eHLFFsNHHjHgg==",
+      "requires": {
+        "tslib": "^2.0.3"
+      }
+    },
     "merge-stream": {
       "version": "2.0.0"
     },
@@ -2249,6 +2315,15 @@
       "version": "1.2.5",
       "dev": true
     },
+    "no-case": {
+      "version": "3.0.4",
+      "resolved": "https://registry.npmjs.org/no-case/-/no-case-3.0.4.tgz",
+      "integrity": "sha512-fgAN3jGAh+RoxUGZHTSOLJIqUc2wmoBwGR4tbpNAKmmovFoWq0OdRkb0VkldReO2a2iBT/OEulG9XSUc10r3zg==",
+      "requires": {
+        "lower-case": "^2.0.2",
+        "tslib": "^2.0.3"
+      }
+    },
     "normalize-path": {
       "version": "3.0.0",
       "dev": true
@@ -2287,6 +2362,15 @@
         "callsites": "^3.0.0"
       }
     },
+    "pascal-case": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/pascal-case/-/pascal-case-3.1.2.tgz",
+      "integrity": "sha512-uWlGT3YSnK9x3BQJaOdcZwrnV6hPpd8jFH1/ucpiLRPh/2zCVJKS19E4GvYHvaCcACn3foXZ0cLB9Wrx1KGe5g==",
+      "requires": {
+        "no-case": "^3.0.4",
+        "tslib": "^2.0.3"
+      }
+    },
     "path-is-absolute": {
       "version": "1.0.1",
       "dev": true
@@ -2416,8 +2500,21 @@
       }
     },
     "svelte-routing": {
-      "version": "1.5.0",
-      "requires": {}
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/svelte-routing/-/svelte-routing-1.6.0.tgz",
+      "integrity": "sha512-+DbrSGttLA6lan7oWFz1MjyGabdn3tPRqn8Osyc471ut2UgCrzM5x1qViNMc2gahOP6fKbKK1aNtZMJEQP2vHQ==",
+      "requires": {
+        "svelte2tsx": "^0.1.157"
+      }
+    },
+    "svelte2tsx": {
+      "version": "0.1.189",
+      "resolved": "https://registry.npmjs.org/svelte2tsx/-/svelte2tsx-0.1.189.tgz",
+      "integrity": "sha512-Mo4Sei1tNYthzSZx6biGSK7pI6/vj7nGvvmSevmLIiws/o1hyj1UIHn+AwqogeA9L46fcvy6WU3t7HxDg+LbLg==",
+      "requires": {
+        "dedent-js": "^1.0.1",
+        "pascal-case": "^3.1.1"
+      }
     },
     "to-regex-range": {
       "version": "5.0.1",
@@ -2426,6 +2523,11 @@
         "is-number": "^7.0.0"
       }
     },
+    "tslib": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.2.0.tgz",
+      "integrity": "sha512-gS9GVHRU+RGn5KQM2rllAlR3dU6m7AcpJKdtH8gFvQiC4Otgk98XnmMU+nZenHt/+VhnBPWwgrJsyrdcw6i23w=="
+    },
     "typescript": {
       "version": "4.2.4"
     },
diff --git a/package.json b/package.json
index 7c889af92..5418d9edf 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,6 @@
     "@snowpack/plugin-typescript": "^1.2.1",
     "ethers": "^5.0.31",
     "svelte": "^3.32.3",
-    "svelte-routing": "^1.5.0"
+    "svelte-routing": "^1.6.0"
   }
 }
diff --git a/src/Header.svelte b/src/Header.svelte
index 11f0bf42a..92e42c6f1 100644
--- a/src/Header.svelte
+++ b/src/Header.svelte
@@ -12,11 +12,12 @@
   import type { Session } from '@app/session';
   import Logo from './Logo.svelte';
   import Connect from './Connect.svelte';
+  import type { Config } from '@app/config';
 
   export let session: Session | null;
-  export let config;
+  export let config: Config;
 
-  let sessionButton = null;
+  let sessionButton: HTMLElement | null = null;
   let sessionButtonHover = false;
 
   $: address = session && session.address;
diff --git a/src/Modal.svelte b/src/Modal.svelte
index b7a370109..b8433924f 100644
--- a/src/Modal.svelte
+++ b/src/Modal.svelte
@@ -2,7 +2,7 @@
   import { createEventDispatcher } from 'svelte';
 
   export let floating = false;
-  export let error = null;
+  export let error: Error | null = null;
 
   let dispatch = createEventDispatcher();
 
diff --git a/src/base/orgs/CreateOrg.svelte b/src/base/orgs/CreateOrg.svelte
index ab209fd00..b4521a666 100644
--- a/src/base/orgs/CreateOrg.svelte
+++ b/src/base/orgs/CreateOrg.svelte
@@ -15,8 +15,8 @@
   }
 
   let state = State.Idle;
-  let error = null;
-  let org = null;
+  let error: Error | null = null;
+  let org: Org | null = null;
 
   const dispatch = createEventDispatcher();
   const createOrg = async () => {
diff --git a/src/base/orgs/Org.ts b/src/base/orgs/Org.ts
index b4246864b..e0b2b6c65 100644
--- a/src/base/orgs/Org.ts
+++ b/src/base/orgs/Org.ts
@@ -20,12 +20,16 @@ export class Org {
     this.safe = safe;
   }
 
-  static fromReceipt(receipt: ContractReceipt): Org {
-    let event = receipt.events.find(e => e.event === 'OrgCreated');
-    let address = event.args[0];
-    let safe = event.args[1];
+  static fromReceipt(receipt: ContractReceipt): Org | null {
+    let event = receipt.events?.find(e => e.event === 'OrgCreated');
 
-    return new Org(address, safe);
+    if (event && event.args) {
+      let address = event.args[0];
+      let safe = event.args[1];
+
+      return new Org(address, safe);
+    }
+    return null;
   }
 
   static async create(
diff --git a/src/base/orgs/Orgs.svelte b/src/base/orgs/Orgs.svelte
index 8e39b299e..c62c23826 100644
--- a/src/base/orgs/Orgs.svelte
+++ b/src/base/orgs/Orgs.svelte
@@ -6,12 +6,13 @@
   import { error } from '@app/error';
   import { session } from '@app/session';
   import CreateOrg from '@app/base/orgs/CreateOrg.svelte';
+  import type { Config } from '@app/config';
 
   enum State {
     Idle,
   }
 
-  export let config;
+  export let config: Config;
   export const query = {};
 
   let modal = null;
diff --git a/src/base/orgs/Routes.svelte b/src/base/orgs/Routes.svelte
index f1a910dc7..f60907345 100644
--- a/src/base/orgs/Routes.svelte
+++ b/src/base/orgs/Routes.svelte
@@ -1,8 +1,9 @@
 <script lang="typescript">
   import { Route } from "svelte-routing";
   import Orgs from '@app/base/orgs/Orgs.svelte';
+  import type { Config } from '@app/config';
 
-  export let config;
+  export let config: Config;
   export let query;
 </script>
 
diff --git a/src/base/register/registrar.ts b/src/base/register/registrar.ts
index fa05e3030..58d90502a 100644
--- a/src/base/register/registrar.ts
+++ b/src/base/register/registrar.ts
@@ -1,9 +1,11 @@
 // TODO: Show "look at your wallet" / "confirm tx" before state change.
 // TODO: Two registration actions with same label
-import { ethers } from "ethers";
+import { ethers } from 'ethers';
+import type { BigNumber } from 'ethers';
 import { State, state } from './state';
 import * as session from '@app/session';
 import { Failure } from '@app/error';
+import type { Config } from '@app/config';
 
 const registrarAbi = [
   {"anonymous":false,"inputs":[{"indexed":false,"internalType":"bytes32","name":"commitment","type":"bytes32"},{"indexed":false,"internalType":"uint256","name":"blockNumber","type":"uint256"}],"name":"CommitmentMade","type":"event"},
@@ -20,15 +22,15 @@ const registrarAbi = [
   {"inputs":[{"internalType":"string","name":"name","type":"string"}],"name":"valid","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"}
 ];
 
-export function registrar(config) {
+export function registrar(config: Config) {
   return new ethers.Contract(config.registrar.address, registrarAbi, config.provider);
 }
 
-export async function registrationFee(config) {
+export async function registrationFee(config: Config) {
   return await registrar(config).registrationFeeRad();
 }
 
-export async function registerName(name, owner, config) {
+export async function registerName(name: string, owner: string, config: Config) {
   if (! name) return;
 
   let commitmentJson = window.localStorage.getItem('commitment');
@@ -47,14 +49,14 @@ export async function registerName(name, owner, config) {
   }
 }
 
-async function approveRegistrar(owner, config) {
+async function approveRegistrar(owner: string, config: Config) {
   state.set(State.Approving);
 
   const amount = await registrationFee(config);
   await session.approveSpender(config.registrar.address, amount, config);
 }
 
-async function commitAndRegister(name, owner, config) {
+async function commitAndRegister(name: string, owner: string, config: Config) {
   let salt = ethers.utils.randomBytes(32);
   let minAge = (await registrar(config).minCommitmentAge()).toNumber();
   let fee = await registrationFee(config);
@@ -71,14 +73,14 @@ async function commitAndRegister(name, owner, config) {
   await register(name, owner, salt, config);
 }
 
-async function commit(commitment, fee, minAge, config) {
+async function commit(commitment: string, fee: BigNumber, minAge: number, config: Config) {
   state.set(State.Committing);
 
   const signer = config.provider.getSigner();
   const tx = await registrar(config)
     .connect(signer)
     .commit(commitment, { gasLimit: 150000 })
-    .catch(e => console.error(e));
+    .catch((e: Error) => console.error(e));
 
   await tx.wait(1);
   session.state.updateBalance(fee.mul(-1));
@@ -88,7 +90,7 @@ async function commit(commitment, fee, minAge, config) {
   await tx.wait(minAge + 1);
 }
 
-async function register(name, owner, salt, config) {
+async function register(name: string, owner: string, salt: Uint8Array, config: Config) {
   state.set(State.Registering);
 
   const signer = config.provider.getSigner();
@@ -102,7 +104,7 @@ async function register(name, owner, salt, config) {
   state.set(State.Registered);
 }
 
-function makeCommitment(name, owner, salt) {
+function makeCommitment(name: string, owner: string, salt: Uint8Array): string {
   let bytes = ethers.utils.concat([
     ethers.utils.toUtf8Bytes(name),
     ethers.utils.getAddress(owner),
diff --git a/src/base/vesting/vesting.ts b/src/base/vesting/vesting.ts
index 33ecd53ac..13738f887 100644
--- a/src/base/vesting/vesting.ts
+++ b/src/base/vesting/vesting.ts
@@ -2,6 +2,7 @@ import { ethers } from "ethers";
 import { formatBalance } from "@app/utils";
 import * as session from "@app/session";
 import { State, state } from "./state";
+import type { Config } from "@app/config";
 
 const abi = [
   "function token() view returns (address)",
@@ -20,7 +21,7 @@ const tokenAbi = [
   "function symbol() view returns (string)",
 ];
 
-export async function withdrawVested(address, config) {
+export async function withdrawVested(address: string, config: Config) {
   const contract = new ethers.Contract(address, abi, config.provider);
   const signer = config.provider.getSigner();
 
@@ -34,7 +35,7 @@ export async function withdrawVested(address, config) {
   state.set(State.Withdrawn);
 }
 
-export async function getInfo(address, config) {
+export async function getInfo(address: string, config: Config) {
   const contract = new ethers.Contract(address, abi, config.provider);
   const signer = config.provider.getSigner();
 
diff --git a/src/session.ts b/src/session.ts
index aeccb94f7..c1b456dbb 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -1,6 +1,7 @@
 // TODO: Handle wallet account change.
 import { get, writable, derived, Writable } from "svelte/store";
 import { ethers } from "ethers";
+import type { BigNumber } from 'ethers';
 import type { TransactionReceipt, TransactionResponse } from '@ethersproject/providers';
 import type { Config } from "@app/config";
 import { Unreachable, assert, assertEq } from "@app/error";
@@ -62,7 +63,7 @@ export const createState = (initial: State) => {
       }
     },
 
-    updateBalance: n => {
+    updateBalance: (n: BigNumber) => {
       store.update((s) => {
         assert(s.connection === Connection.Connected);
         s.session.tokenBalance = s.session.tokenBalance.add(n);
@@ -70,7 +71,7 @@ export const createState = (initial: State) => {
       });
     },
 
-    refreshBalance: async (config) => {
+    refreshBalance: async (config: Config) => {
       let state = get(store);
       assert(state.connection === Connection.Connected);
       const addr = state.session.address;
@@ -102,6 +103,9 @@ export const createState = (initial: State) => {
       store.update(s => {
         switch (s.connection) {
           case Connection.Connected:
+            assert(s.session.tx !== null);
+            assert(s.session.tx.state === 'signing');
+
             s.session.tx = { state: 'pending', hash: tx.hash };
             return s;
           default:
@@ -114,6 +118,7 @@ export const createState = (initial: State) => {
       store.update(s => {
         switch (s.connection) {
           case Connection.Connected:
+            assert(s.session.tx !== null);
             assert(s.session.tx.state === 'pending');
 
             if (tx.status === 1) {
@@ -159,7 +164,7 @@ const tokenAbi = [
   "function allowance(address, address) view returns (uint256)",
 ];
 
-export async function approveSpender(spender, amount, config) {
+export async function approveSpender(spender: string, amount: BigNumber, config: Config) {
   const token = new ethers.Contract(config.radToken.address, tokenAbi, config.provider);
   const signer = config.provider.getSigner();
   const addr = await signer.getAddress();
diff --git a/src/utils.ts b/src/utils.ts
index e4ed12da5..e77162c24 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,10 +1,11 @@
 import { ethers } from "ethers";
+import type { BigNumber } from "ethers";
 
-export function formatBalance(n) {
+export function formatBalance(n: BigNumber) {
   return ethers.utils.commify(parseFloat(ethers.utils.formatUnits(n)).toFixed(2));
 }
 
-export function formatAddress(addr) {
+export function formatAddress(addr: string) {
   return addr.substring(0, 6)
     + '...'
     + addr.substring(addr.length - 4, addr.length);