diff --git a/README.md b/README.md
index 46f9cc480..0298262fc 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,35 @@ The autogenerated OSAL user's guide can be viewed at <https://github.com/nasa/cF
 
 ## Version History
 
+
+### Development Build: v5.1.0-rc1+dev345
+
+- Moves copyblock size to a macro and add comments. Defines `OS_CP_BLOCK_SIZE` and adds clear documentation that it could be adjusted for page size, performance, etc.
+- Removes while loop
+- Replaces all #includes of <os and <OSC_ matches with " to match coding standard.
+- Consolidates the duplicated switch in `OS_SocketOpen_Impl`
+- Add const to input pointers for `OS_FdSet_ConvertIn_Impl` and `OS_ObjectIdTransactionFinish`
+- Removes network prototypes defined in `osapi_sockets.h` that are also in `osapi_network.h`
+- Removes `NULL` redefine from `common_types.h`
+- Adds `Contributing.md` that points to bundle-level contribution guide
+- Reports test cases that "fail" as "not implemented" with new `UtAssert_NA` macro instead of `UtPrintf`
+- Calls to `OS_SelectSingle` and `OS_SelectMultiple` will fail if an FD within the set is outside the range of the underlying `FD_SETSIZE` from the C library.
+- Fixes calculation used for the relative time interval in the `select()` call. Also adds a UT case that specifically exercises the carryover described. Fixes delay when this carry condition is hit
+- Documents algorithm that provides application-controlled timeout on the connection initiation. Also adds a debug statement if the connect fails for a reason other than `EINPROGRESS`. No impact to normal behavior.
+- Adds check for `EAGAIN` if the system fails to allocate kernel-internal resources.
+- Adds a `CompileTimeAssert` to confirm that the size of the abstract buffer for socket addresses is large enough to store any of the enabled address types thereby removing the need for runtime tests.
+- With this change, if `OS_SOCKADDR_MAX_LENis` not large enough for the address type, osal will fail to compile. This enforces that the abstract size is large enough for any/all enabled address types, regardless of what is actually used.
+- Adds missing functional test for `OS_ShellOutputToFile`
+- Add test for `fcntl()` error return of -1 and report errno. If setting `O_NONBLOCK` fails, then debug message is printed and blocking mode is used and timeouts will not work as a result.
+- Improves error codes when attempting to seek on a pipe/socket. Translates the `OS_ERR_OPERATION_NOT_SUPPORTED` error rather than "not implemented". The `ESPIPE` errno means that seeking is not supported on the given file handle.
+- Renames `OS_U32ValueWrapper_t` as `OS_VoidPtrValueWrapper_t` to better indicate its purpose. The point is to pass a value through a `void*`. Adds a compile-time assert to check that this is only used to directly pass values which have a size of less than or equal to sizeof(void*).
+- Refactors the return statement for `OS_FileSys_FindVirtMountPoint()` so it is easier to read and adds some informational comments.
+- Reports an error if calling `timer_gettime` after `timer_settime` fails.
+- Returns `OS_ERROR` status to caller after an error on moduleInfoGet()
+- Removes an extraneous/unreachable OS_ObjectIdDefined check and its accompanying debug statement. The only way this check could have been reached would be if the normal unlock process was bypassed such that the underlying OS mutex was unlocked but OSAL state still had it owned by a task. This condition never happens at runtime.
+- Updates documentation for `OS_MAX_MODULE`
+- See <https://github.com/nasa/osal/pull/917>
+
 ### Development Build: v5.1.0-rc1+dev297
 
 - Fix #836, Add Testing Tools to the Security Policy
diff --git a/src/os/inc/osapi-version.h b/src/os/inc/osapi-version.h
index 45db59c9f..11367b8af 100644
--- a/src/os/inc/osapi-version.h
+++ b/src/os/inc/osapi-version.h
@@ -32,7 +32,7 @@
 /*
  * Development Build Macro Definitions
  */
-#define OS_BUILD_NUMBER   297
+#define OS_BUILD_NUMBER   345
 #define OS_BUILD_BASELINE "v5.1.0-rc1"
 
 /*