diff --git a/docs/api.md b/docs/api.md
index 1fa3ea2..847ab3e 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -3,6 +3,7 @@
 ### system
 #### spawn(*name*, *function*, *environment*)
 Spawns a process from *function* called *name* with *environment*.
+
 ### os
 #### os.getenv(*k*)
 Gets the *k* environment variable for the current process.
@@ -12,35 +13,70 @@ Sets the *k* environment variable to *v* for the current process.
 Returns a list of current processes running, the key being the pid and the value being the name.
 #### os.taskinfo(*pid*)
 Returns the name, parent process, and user ID for process *pid*.
+
 ### event
 #### event.get()
 Gets the next event in the event queue for the process.
 #### event.pull(*type*)
 Gets, and possibly waits, for an event, optionally with *type
+
 ### buffer
 #### buffer.create(*w*, *c*)
 Creates a buffer with worker function *w* and close function *c*. *w* is called on creation with the buffer as the argument.
-### I/O stuff
-#### write(...)
+
+### filesystem
+#### fs.mount(*mp*, *pr*)
+Mounts the component proxy *pr* to mountpoint *mp*.
+#### fs.simplify(*path*)
+Simplifies *path* by resolving .. and . and similar.
+#### fs.resolve(*path*)
+Resolves *path* to a table of path elements, a mountpoint and a relative filesystem path.
+#### fs.open(*path*,*mode*)
+Returns a system file handle usable by other fs functions for *path* in *mode*. Modes can be r, w, a, rb, wb, ab.
+#### fs.close(*handle*)
+Closes a system file handle.
+#### fs.read(*handle*,*length*)
+Reads *length* bytes of data from *handle*. *length* is usually limited to 2048.
+#### fs.write(*handle*,*data*)
+Writes *data* to *handle*.
+#### fs.readall(*handle*)
+Returns as much data as can be read from *handle*.
+
+### io
+#### write(...) or io.write(...)
 Writes its arguments to the I/O device.
 #### print(...)
 Writes its arguments to the I/O device, with a newline after each.
-#### readln(*rch*)
-Reads a line from the I/O device, optionally replacing the echoed characters with *rch*.
+#### readln(*rch*) or io.read(...)
+Reads a line from the I/O device, optionally replacing the echoed characters with *rch*.a
+#### io.open(*path*,*mode*)
+Returns a file object for *path* in *mode*.
+##### fobj:read(*len*)
+If *len* is a number, reads *len* bytes from *fobj*. If *len* is "\*a", it reads all the data from *fobj*. If *len* is "\*l", it reads a line from *fobj*.
+##### fobj:write(*data*)
+Writes *data* to *fobj* (if in write mode)
+##### fobj:close()
+Closes *fobj*, flushing buffers and removing the object from memory.
+
 ### drivers
 #### tty(*gA*, *sA*, *sI*, *fg*, *bg*)
 Creates a GPU driver instance for GPU *gA* and screen *sA* attached to session *sI*, optionally with foreground and background colours *fg* and *bg*.
 #### kbd(*kA*, *sI*)
 Creates a keyboard driver instance for keyboard *kA* attached to session *sI*.
+
+
 ## Events
 ### Network
 #### net\_msg, *from*, *port*, *message*
 Queued when the system receives message *message* from *from* on port *port*.
+
 ### Terminal I/O
 #### key, *session*, *char*, *code*
 A key with value *char* and code *code* was pressed and parsed by a keyboard handler attached to session *session*
 #### display, *session*, *text*
 This is triggered to make a tty driver attached to *session* write *text* to the screen. Ideally, use write(), not the raw event.
+
+
 ## Applications
 ### luash(*sI*)
 Spawns a luash instance for session *sI*