diff --git a/Cargo.lock b/Cargo.lock
index 8a314f5..7e69b62 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1792,7 +1792,7 @@ dependencies = [
 
 [[package]]
 name = "imcp2"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "anyhow",
  "axum",
@@ -1822,7 +1822,7 @@ dependencies = [
 
 [[package]]
 name = "imcp2-core"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "base64 0.22.1",
  "candid",
@@ -1845,7 +1845,7 @@ dependencies = [
 
 [[package]]
 name = "imcp2-local"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "anyhow",
  "axum",
diff --git a/Cargo.toml b/Cargo.toml
index 0633b11..9e1b282 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "imcp2"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 description = "Minimal MCP server that bridges an LLM to the Internet Computer, speaking textual Candid."
 license = "Apache-2.0"
@@ -44,7 +44,7 @@ dist = false
 # codec, and candid lines can never drift between imcp2-core, imcp2, and
 # imcp2-local.
 [workspace.dependencies]
-imcp2-core = { path = "crates/imcp2-core", version = "0.3.0" }
+imcp2-core = { path = "crates/imcp2-core", version = "0.4.0" }
 rmcp = "1.7"
 axum = "0.8"
 anyhow = "1"
diff --git a/README.md b/README.md
index 6ea4589..7eedca1 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,7 @@ Published on [crates.io](https://crates.io/crates/imcp2), API docs on
 
 ```toml
 [dependencies]
-imcp2 = "0.3"
+imcp2 = "0.4"
 ```
 
 One `McpServer` serves one Internet Identity instance as two
diff --git a/crates/imcp2-core/Cargo.toml b/crates/imcp2-core/Cargo.toml
index 4ef83f7..6991afb 100644
--- a/crates/imcp2-core/Cargo.toml
+++ b/crates/imcp2-core/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "imcp2-core"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 description = "Transport-agnostic components of the IMCP2 Internet Computer MCP server: the tool surface, the Internet Identity session engine, and the II connect-handshake primitives."
 license = "Apache-2.0"
diff --git a/crates/imcp2-local/Cargo.toml b/crates/imcp2-local/Cargo.toml
index 29f44f2..7227136 100644
--- a/crates/imcp2-local/Cargo.toml
+++ b/crates/imcp2-local/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "imcp2-local"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 description = "Local MCP server for the Internet Computer: the imcp2 tool surface over stdio, with a built-in Internet Identity browser login."
 license = "Apache-2.0"