diff --git a/Cargo.toml b/Cargo.toml
index 4794b1e..253bbe1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,14 +4,13 @@ version = "0.1.0"
 edition = "2021"
 license = "Apache-2.0"
 description = "binary size-effective format used in Divan smart contracts, wasm bindings, network protocols, etc."
+homepage = "https://gitea.sergeych.net/Divan/bipack_ru"
+repository = "https://gitea.sergeych.net/Divan/bipack_ru"
+readme = "README.md"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-#anyhow = "1.0"
-lazy_static = "1.4.0"
-string-builder = "0.2.0"
 
 [dev-dependencies]
 base64 = "0.21.4"
-hex = "0.4.3"
-derive_more = "0.99.17"
\ No newline at end of file
+hex = "0.4.3"
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 308917b..d95c51b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -34,6 +34,8 @@
 //! - [tools::to_dump] utility function converts binary data into human-readable dump as in old goot
 //!   times (address, bytes, ASCII characters).
 //!
+//! - [tools::StringBuilder] minimalistic growing strings builder.
+//!
 //! ## About Bipack format
 //!
 //! This is a binary format created wround the idea of bit-effectiveness and not disclosing
@@ -190,7 +192,13 @@ mod tests {
             for u in 0..l {
                 d2.push(u as u8);
             }
-            println!("size {}\n{}", d2.len(), to_dump(&d2));
+            // println!("size {}\n{}", d2.len(), to_dump(&d2));
+            if d2.len() == 41 {
+                let x = to_dump(&d2);
+                assert_eq!(x, "0000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f |................|
+0010 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f |................|
+0020 20 21 22 23 24 25 26 27 28                      | !\"#$%&'(       |\n");
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/src/tools.rs b/src/tools.rs
index 661728e..0bedb65 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -12,7 +12,33 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use string_builder::Builder;
+// use string_builder::Builder;
+
+use std::string::FromUtf8Error;
+
+/// Absolutely minimalistic string builder (growing string implemented minimal and
+/// more or less effective). Just to avoid dependencies for better .wasm usage.
+pub struct StringBuilder(Vec<u8>);
+
+impl StringBuilder {
+    /// Append something string-like (you can use &str and String for example) to the buffer.
+    fn append<T: AsRef<str>>(self: &mut Self, text: T) {
+        for b in text.as_ref().bytes() { self.0.push(b) }
+    }
+
+    /// Append char as far as it is a valid char in rust limited sense:
+    fn append_char(self: &mut Self, c: char) {
+        self.append(String::from(c))
+    }
+
+    /// Finalize the builder and return the result string.
+    fn string(self: &mut Self) -> Result<String, FromUtf8Error> {
+        String::from_utf8(self.0.clone())
+    }
+
+    fn new() -> StringBuilder { StringBuilder(Vec::new()) }
+}
+
 
 /// Convert binary data into text dump, human readable, like:
 /// ```text
@@ -24,20 +50,20 @@ use string_builder::Builder;
 pub fn to_dump(data: &[u8]) -> String {
     let mut offset = 0usize;
     let mut counter = 0;
-    let mut result = Builder::default();
+    let mut result = StringBuilder::new();
 
-    fn ascii_dump(result: &mut Builder, counter: usize, data: &[u8], offset: usize) {
+    fn ascii_dump(result: &mut StringBuilder, counter: usize, data: &[u8], offset: usize) {
         for i in counter..16 { result.append("   "); }
         result.append("|");
         for i in 0..counter {
             let b = data[offset - counter + i];
             if b >= 32 && b <= 127 {
-                result.append(b as char)
+                result.append_char(b as char)
             } else {
-                result.append('.');
+                result.append_char('.');
             }
         }
-        for i in counter..16 { result.append(' '); }
+        for i in counter..16 { result.append_char(' '); }
         result.append("|\n");
     }