diff --git a/rln/librln.h b/rln/librln.h
new file mode 100644
index 0000000..8cca80a
--- /dev/null
+++ b/rln/librln.h
@@ -0,0 +1,35 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef struct RLN_Bn256 RLN_Bn256;
+
+/**
+ * Buffer struct is taken from
+ * https://github.com/celo-org/celo-threshold-bls-rs/blob/master/crates/threshold-bls-ffi/src/ffi.rs
+ */
+typedef struct Buffer {
+  const uint8_t *ptr;
+  uintptr_t len;
+} Buffer;
+
+bool new_circuit_from_params(uintptr_t merkle_depth,
+                             const struct Buffer *parameters_buffer,
+                             struct RLN_Bn256 **ctx);
+
+bool generate_proof(const struct RLN_Bn256 *ctx,
+                    const struct Buffer *input_buffer,
+                    struct Buffer *output_buffer);
+
+bool verify(const struct RLN_Bn256 *ctx,
+            const struct Buffer *proof_buffer,
+            const struct Buffer *public_inputs_buffer,
+            uint32_t *result_ptr);
+
+bool hash(const struct RLN_Bn256 *ctx,
+          const struct Buffer *inputs_buffer,
+          const uintptr_t *input_len,
+          struct Buffer *output_buffer);
+
+bool key_gen(const struct RLN_Bn256 *ctx, struct Buffer *keypair_buffer);