diff --git a/get.js b/get.js
index 2bb3afa..6ea6914 100644
--- a/get.js
+++ b/get.js
@@ -2,6 +2,7 @@
 
 const BB = require('bluebird')
 
+const figgyPudding = require('figgy-pudding')
 const fs = require('fs')
 const index = require('./lib/entry-index')
 const memo = require('./lib/memoization')
@@ -10,6 +11,12 @@ const pipeline = require('mississippi').pipeline
 const read = require('./lib/content/read')
 const through = require('mississippi').through
 
+const GetOpts = figgyPudding({
+  integrity: {},
+  memoize: {},
+  size: {}
+})
+
 module.exports = function get (cache, key, opts) {
   return getData(false, cache, key, opts)
 }
@@ -17,7 +24,7 @@ module.exports.byDigest = function getByDigest (cache, digest, opts) {
   return getData(true, cache, digest, opts)
 }
 function getData (byDigest, cache, key, opts) {
-  opts = opts || {}
+  opts = GetOpts(opts)
   const memoized = (
     byDigest
     ? memo.get.byDigest(cache, key, opts)
@@ -58,7 +65,7 @@ function getData (byDigest, cache, key, opts) {
 
 module.exports.stream = getStream
 function getStream (cache, key, opts) {
-  opts = opts || {}
+  opts = GetOpts(opts)
   let stream = through()
   const memoized = memo.get(cache, key, opts)
   if (memoized && opts.memoize !== false) {
@@ -91,7 +98,6 @@ function getStream (cache, key, opts) {
     } else {
       memoStream = through()
     }
-    opts.size = opts.size == null ? entry.size : opts.size
     stream.emit('metadata', entry.metadata)
     stream.emit('integrity', entry.integrity)
     stream.emit('size', entry.size)
@@ -101,7 +107,9 @@ function getStream (cache, key, opts) {
       ev === 'size' && cb(entry.size)
     })
     pipe(
-      read.readStream(cache, entry.integrity, opts),
+      read.readStream(cache, entry.integrity, opts.concat({
+        size: opts.size == null ? entry.size : opts.size
+      })),
       memoStream,
       stream
     )
@@ -111,7 +119,7 @@ function getStream (cache, key, opts) {
 
 module.exports.stream.byDigest = getStreamDigest
 function getStreamDigest (cache, integrity, opts) {
-  opts = opts || {}
+  opts = GetOpts(opts)
   const memoized = memo.get.byDigest(cache, integrity, opts)
   if (memoized && opts.memoize !== false) {
     const stream = through()
@@ -143,7 +151,7 @@ function getStreamDigest (cache, integrity, opts) {
 
 module.exports.info = info
 function info (cache, key, opts) {
-  opts = opts || {}
+  opts = GetOpts(opts)
   const memoized = memo.get(cache, key, opts)
   if (memoized && opts.memoize !== false) {
     return BB.resolve(memoized.entry)
@@ -161,7 +169,7 @@ module.exports.copy.byDigest = function cpDigest (cache, digest, dest, opts) {
   return copy(true, cache, digest, dest, opts)
 }
 function copy (byDigest, cache, key, dest, opts) {
-  opts = opts || {}
+  opts = GetOpts(opts)
   if (read.copy) {
     return (
       byDigest ? BB.resolve(null) : index.find(cache, key, opts)
diff --git a/lib/content/read.js b/lib/content/read.js
index 7a4da3b..ec99962 100644
--- a/lib/content/read.js
+++ b/lib/content/read.js
@@ -3,6 +3,7 @@
 const BB = require('bluebird')
 
 const contentPath = require('./path')
+const figgyPudding = require('figgy-pudding')
 const fs = require('graceful-fs')
 const PassThrough = require('stream').PassThrough
 const pipe = BB.promisify(require('mississippi').pipe)
@@ -11,9 +12,13 @@ const Y = require('../util/y.js')
 
 BB.promisifyAll(fs)
 
+const ReadOpts = figgyPudding({
+  size: {}
+})
+
 module.exports = read
 function read (cache, integrity, opts) {
-  opts = opts || {}
+  opts = ReadOpts(opts)
   return pickContentSri(cache, integrity).then(content => {
     const sri = content.sri
     const cpath = contentPath(cache, sri)
@@ -32,7 +37,7 @@ function read (cache, integrity, opts) {
 module.exports.stream = readStream
 module.exports.readStream = readStream
 function readStream (cache, integrity, opts) {
-  opts = opts || {}
+  opts = ReadOpts(opts)
   const stream = new PassThrough()
   pickContentSri(
     cache, integrity
@@ -56,7 +61,7 @@ if (fs.copyFile) {
   module.exports.copy = copy
 }
 function copy (cache, integrity, dest, opts) {
-  opts = opts || {}
+  opts = ReadOpts(opts)
   return pickContentSri(cache, integrity).then(content => {
     const sri = content.sri
     const cpath = contentPath(cache, sri)
diff --git a/lib/content/write.js b/lib/content/write.js
index a79ae92..c713634 100644
--- a/lib/content/write.js
+++ b/lib/content/write.js
@@ -28,7 +28,9 @@ function write (cache, data, opts) {
   if (typeof opts.size === 'number' && data.length !== opts.size) {
     return BB.reject(sizeError(opts.size, data.length))
   }
-  const sri = ssri.fromData(data, opts)
+  const sri = ssri.fromData(data, {
+    algorithms: opts.algorithms
+  })
   if (opts.integrity && !ssri.checkData(data, opts.integrity, opts)) {
     return BB.reject(checksumError(opts.integrity, sri))
   }
diff --git a/lib/entry-index.js b/lib/entry-index.js
index fe1cd06..226f654 100644
--- a/lib/entry-index.js
+++ b/lib/entry-index.js
@@ -4,6 +4,7 @@ const BB = require('bluebird')
 
 const contentPath = require('./content/path')
 const crypto = require('crypto')
+const figgyPudding = require('figgy-pudding')
 const fixOwner = require('./util/fix-owner')
 const fs = require('graceful-fs')
 const hashToSegments = require('./util/hash-to-segments')
@@ -29,9 +30,16 @@ module.exports.NotFoundError = class NotFoundError extends Error {
   }
 }
 
+const IndexOpts = figgyPudding({
+  metadata: {},
+  size: {},
+  uid: {},
+  gid: {}
+})
+
 module.exports.insert = insert
 function insert (cache, key, integrity, opts) {
-  opts = opts || {}
+  opts = IndexOpts(opts)
   const bucket = bucketPath(cache, key)
   const entry = {
     key,
diff --git a/lib/util/tmp.js b/lib/util/tmp.js
index 4fc4512..65fc4b2 100644
--- a/lib/util/tmp.js
+++ b/lib/util/tmp.js
@@ -2,14 +2,21 @@
 
 const BB = require('bluebird')
 
+const figgyPudding = require('figgy-pudding')
 const fixOwner = require('./fix-owner')
 const path = require('path')
 const rimraf = BB.promisify(require('rimraf'))
 const uniqueFilename = require('unique-filename')
 
+const TmpOpts = figgyPudding({
+  tmpPrefix: {},
+  uid: {},
+  gid: {}
+})
+
 module.exports.mkdir = mktmpdir
 function mktmpdir (cache, opts) {
-  opts = opts || {}
+  opts = TmpOpts(opts)
   const tmpTarget = uniqueFilename(path.join(cache, 'tmp'), opts.tmpPrefix)
   return fixOwner.mkdirfix(tmpTarget, opts.uid, opts.gid).then(() => {
     return tmpTarget
@@ -22,11 +29,12 @@ function withTmp (cache, opts, cb) {
     cb = opts
     opts = null
   }
-  opts = opts || {}
+  opts = TmpOpts(opts)
   return BB.using(mktmpdir(cache, opts).disposer(rimraf), cb)
 }
 
 module.exports.fix = fixtmpdir
 function fixtmpdir (cache, opts) {
+  opts = TmpOpts(opts)
   return fixOwner(path.join(cache, 'tmp'), opts.uid, opts.gid)
 }
diff --git a/lib/verify.js b/lib/verify.js
index 6a01004..80d59bd 100644
--- a/lib/verify.js
+++ b/lib/verify.js
@@ -3,6 +3,7 @@
 const BB = require('bluebird')
 
 const contentPath = require('./content/path')
+const figgyPudding = require('figgy-pudding')
 const finished = BB.promisify(require('mississippi').finished)
 const fixOwner = require('./util/fix-owner')
 const fs = require('graceful-fs')
@@ -14,10 +15,22 @@ const ssri = require('ssri')
 
 BB.promisifyAll(fs)
 
+const VerifyOpts = figgyPudding({
+  concurrency: {
+    default: 20
+  },
+  filter: {},
+  log: {
+    default: { silly () {} }
+  },
+  uid: {},
+  gid: {}
+})
+
 module.exports = verify
 function verify (cache, opts) {
-  opts = opts || {}
-  opts.log && opts.log.silly('verify', 'verifying cache at', cache)
+  opts = VerifyOpts(opts)
+  opts.log.silly('verify', 'verifying cache at', cache)
   return BB.reduce([
     markStartTime,
     fixPerms,
@@ -40,7 +53,7 @@ function verify (cache, opts) {
     })
   }, {}).tap(stats => {
     stats.runTime.total = stats.endTime - stats.startTime
-    opts.log && opts.log.silly('verify', 'verification finished for', cache, 'in', `${stats.runTime.total}ms`)
+    opts.log.silly('verify', 'verification finished for', cache, 'in', `${stats.runTime.total}ms`)
   })
 }
 
@@ -53,7 +66,7 @@ function markEndTime (cache, opts) {
 }
 
 function fixPerms (cache, opts) {
-  opts.log && opts.log.silly('verify', 'fixing cache permissions')
+  opts.log.silly('verify', 'fixing cache permissions')
   return fixOwner.mkdirfix(cache, opts.uid, opts.gid).then(() => {
     // TODO - fix file permissions too
     return fixOwner.chownr(cache, opts.uid, opts.gid)
@@ -70,11 +83,11 @@ function fixPerms (cache, opts) {
 // 5. If content is not marked as live, rimraf it.
 //
 function garbageCollect (cache, opts) {
-  opts.log && opts.log.silly('verify', 'garbage collecting content')
+  opts.log.silly('verify', 'garbage collecting content')
   const indexStream = index.lsStream(cache)
   const liveContent = new Set()
   indexStream.on('data', entry => {
-    if (opts && opts.filter && !opts.filter(entry)) { return }
+    if (opts.filter && !opts.filter(entry)) { return }
     liveContent.add(entry.integrity.toString())
   })
   return finished(indexStream).then(() => {
@@ -117,7 +130,7 @@ function garbageCollect (cache, opts) {
             })
           })
         }
-      }, {concurrency: opts.concurrency || 20}))
+      }, {concurrency: opts.concurrency}))
     })
   })
 }
@@ -141,7 +154,7 @@ function verifyContent (filepath, sri) {
 }
 
 function rebuildIndex (cache, opts) {
-  opts.log && opts.log.silly('verify', 'rebuilding index')
+  opts.log.silly('verify', 'rebuilding index')
   return index.ls(cache).then(entries => {
     const stats = {
       missingContent: 0,
@@ -153,7 +166,7 @@ function rebuildIndex (cache, opts) {
       if (entries.hasOwnProperty(k)) {
         const hashed = index._hashKey(k)
         const entry = entries[k]
-        const excluded = opts && opts.filter && !opts.filter(entry)
+        const excluded = opts.filter && !opts.filter(entry)
         excluded && stats.rejectedEntries++
         if (buckets[hashed] && !excluded) {
           buckets[hashed].push(entry)
@@ -170,7 +183,7 @@ function rebuildIndex (cache, opts) {
     }
     return BB.map(Object.keys(buckets), key => {
       return rebuildBucket(cache, buckets[key], stats, opts)
-    }, {concurrency: opts.concurrency || 20}).then(() => stats)
+    }, {concurrency: opts.concurrency}).then(() => stats)
   })
 }
 
@@ -195,13 +208,13 @@ function rebuildBucket (cache, bucket, stats, opts) {
 }
 
 function cleanTmp (cache, opts) {
-  opts.log && opts.log.silly('verify', 'cleaning tmp directory')
+  opts.log.silly('verify', 'cleaning tmp directory')
   return rimraf(path.join(cache, 'tmp'))
 }
 
 function writeVerifile (cache, opts) {
   const verifile = path.join(cache, '_lastverified')
-  opts.log && opts.log.silly('verify', 'writing verifile to ' + verifile)
+  opts.log.silly('verify', 'writing verifile to ' + verifile)
   return fs.writeFileAsync(verifile, '' + (+(new Date())))
 }
 
diff --git a/package-lock.json b/package-lock.json
index a655ab5..e86e173 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1375,6 +1375,11 @@
       "integrity": "sha1-PYpcZog6FqMMqGQ+hR8Zuqd5eRc=",
       "dev": true
     },
+    "figgy-pudding": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/figgy-pudding/-/figgy-pudding-3.1.0.tgz",
+      "integrity": "sha512-Gi2vIue0ec6P/7LNpueGhLuvfF2ztuterl8YFBQn1yKgIS46noGxCbi+vviPdObNYtgUSh5FpHy5q0Cw9XhxKQ=="
+    },
     "figures": {
       "version": "1.7.0",
       "resolved": "https://registry.npmjs.org/figures/-/figures-1.7.0.tgz",
diff --git a/package.json b/package.json
index f3dda96..876dda2 100644
--- a/package.json
+++ b/package.json
@@ -60,6 +60,7 @@
   "dependencies": {
     "bluebird": "^3.5.1",
     "chownr": "^1.0.1",
+    "figgy-pudding": "^3.1.0",
     "glob": "^7.1.2",
     "graceful-fs": "^4.1.11",
     "lru-cache": "^4.1.1",
diff --git a/put.js b/put.js
index fe1293e..0b0ee14 100644
--- a/put.js
+++ b/put.js
@@ -1,17 +1,31 @@
 'use strict'
 
+const figgyPudding = require('figgy-pudding')
 const index = require('./lib/entry-index')
 const memo = require('./lib/memoization')
 const write = require('./lib/content/write')
 const to = require('mississippi').to
 
+const PutOpts = figgyPudding({
+  algorithms: {
+    default: ['sha512']
+  },
+  integrity: {},
+  memoize: {},
+  metadata: {},
+  size: {},
+  tmpPrefix: {},
+  uid: {},
+  gid: {}
+})
+
 module.exports = putData
 function putData (cache, key, data, opts) {
-  opts = opts || {}
+  opts = PutOpts(opts)
   return write(cache, data, opts).then(res => {
-    // TODO - stop modifying opts
-    opts.size = res.size
-    return index.insert(cache, key, res.integrity, opts).then(entry => {
+    return index.insert(
+      cache, key, res.integrity, opts.concat({size: res.size})
+    ).then(entry => {
       if (opts.memoize) {
         memo.put(cache, entry, data, opts)
       }
@@ -22,7 +36,7 @@ function putData (cache, key, data, opts) {
 
 module.exports.stream = putStream
 function putStream (cache, key, opts) {
-  opts = opts || {}
+  opts = PutOpts(opts)
   let integrity
   let size
   const contentStream = write.stream(
@@ -45,9 +59,7 @@ function putStream (cache, key, opts) {
     })
   }, cb => {
     contentStream.end(() => {
-      // TODO - stop modifying `opts`
-      opts.size = size
-      index.insert(cache, key, integrity, opts).then(entry => {
+      index.insert(cache, key, integrity, opts.concat({size})).then(entry => {
         if (opts.memoize) {
           memo.put(cache, entry, Buffer.concat(memoData, memoTotal), opts)
         }