diff --git a/_primitives/_rust/Cargo.lock b/_primitives/_rust/Cargo.lock
index 897a6ea..d469483 100644
--- a/_primitives/_rust/Cargo.lock
+++ b/_primitives/_rust/Cargo.lock
@@ -713,7 +713,7 @@ dependencies = [
  "rustls-pki-types",
  "tokio",
  "tokio-rustls 0.26.4",
- "tower",
+ "tower 0.5.3",
  "tracing",
 ]
 
@@ -889,7 +889,7 @@ dependencies = [
  "sync_wrapper 1.0.2",
  "tokio",
  "tokio-tungstenite 0.24.0",
- "tower",
+ "tower 0.5.3",
  "tower-layer",
  "tower-service",
  "tracing",
@@ -1574,12 +1574,11 @@ dependencies = [
 
 [[package]]
 name = "dashmap"
-version = "6.1.0"
+version = "5.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5041cc499144891f3790297212f32a74fb938e5136a14943f338ef9e0ae276cf"
+checksum = "978747c1d849a7d2ee5e8adc0159961c48fb7e5db2f06af6723b80123bb53856"
 dependencies = [
  "cfg-if",
- "crossbeam-utils",
  "hashbrown 0.14.5",
  "lock_api",
  "once_cell",
@@ -3186,6 +3185,18 @@ dependencies = [
  "thiserror 1.0.69",
 ]
 
+[[package]]
+name = "kei-buddy"
+version = "0.1.0"
+dependencies = [
+ "clap",
+ "serde",
+ "serde_json",
+ "thiserror 1.0.69",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "kei-cache"
 version = "0.1.0"
@@ -3366,7 +3377,7 @@ dependencies = [
  "tokio-stream",
  "tokio-util",
  "toml",
- "tower",
+ "tower 0.4.13",
  "tower-http 0.5.2",
  "url",
  "uuid",
@@ -3530,7 +3541,7 @@ dependencies = [
  "serde_json",
  "tempfile",
  "tokio",
- "tower",
+ "tower 0.4.13",
  "tracing",
  "tracing-subscriber",
 ]
@@ -3683,22 +3694,6 @@ dependencies = [
  "toml",
 ]
 
-[[package]]
-name = "kei-graph-stream"
-version = "0.1.0"
-dependencies = [
- "anyhow",
- "axum",
- "clap",
- "futures",
- "reqwest 0.12.28",
- "serde",
- "serde_json",
- "tempfile",
- "tokio",
- "tokio-tungstenite 0.29.0",
-]
-
 [[package]]
 name = "kei-hibernate"
 version = "0.1.0"
@@ -4500,11 +4495,11 @@ dependencies = [
 
 [[package]]
 name = "kqueue-sys"
-version = "1.0.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed9625ffda8729b85e45cf04090035ac368927b8cebc34898e7c120f52e4838b"
+checksum = "a7b65860415f949f23fa882e669f2dbd4a0f0eeb1acdd56790b30494afd7da2f"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.11.1",
  "libc",
 ]
 
@@ -5894,7 +5889,7 @@ dependencies = [
  "tokio",
  "tokio-rustls 0.26.4",
  "tokio-util",
- "tower",
+ "tower 0.5.3",
  "tower-http 0.6.8",
  "tower-service",
  "url",
@@ -7546,6 +7541,23 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
 
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tokio",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "tower"
 version = "0.5.3"
@@ -7557,7 +7569,6 @@ dependencies = [
  "pin-project-lite",
  "sync_wrapper 1.0.2",
  "tokio",
- "tokio-util",
  "tower-layer",
  "tower-service",
  "tracing",
@@ -7593,7 +7604,7 @@ dependencies = [
  "http-body 1.0.1",
  "iri-string",
  "pin-project-lite",
- "tower",
+ "tower 0.5.3",
  "tower-layer",
  "tower-service",
 ]
diff --git a/_primitives/_rust/Cargo.toml b/_primitives/_rust/Cargo.toml
index 4cabd3e..d7b6572 100644
--- a/_primitives/_rust/Cargo.toml
+++ b/_primitives/_rust/Cargo.toml
@@ -179,6 +179,8 @@ members = [
     "kei-db-contract",
     # Live runtime-graph exporter (registry + ledger → D3 space fragment)
     "kei-graph-export",
+    # KeiBuddy personal-assistant Telegram bot — onboarding FSM scaffold
+    "kei-buddy",
 ]
 
 [workspace.package]
diff --git a/_primitives/_rust/kei-buddy/Cargo.toml b/_primitives/_rust/kei-buddy/Cargo.toml
new file mode 100644
index 0000000..1f77f50
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/Cargo.toml
@@ -0,0 +1,33 @@
+[package]
+name = "kei-buddy"
+version = "0.1.0"
+edition.workspace = true
+rust-version.workspace = true
+description = "KeiBuddy personal-assistant Telegram bot — onboarding state-machine + skeleton driver. Concept-level scaffold."
+authors.workspace = true
+license.workspace = true
+
+[[bin]]
+name = "kei-buddy"
+path = "src/bin/kei-buddy.rs"
+
+[lib]
+name = "kei_buddy"
+path = "src/lib.rs"
+
+[dependencies]
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
+tracing = "0.1"
+clap = { workspace = true, features = ["derive"] }
+
+[features]
+# future: pulls in kei-notify-telegram for real Telegram transport
+telegram = []
+
+[package.metadata.keisei]
+maturity = "concept"
+description = "KeiBuddy personal-assistant: onboarding FSM + bot driver scaffold"
+authors = ["Denis Parfionovich <parfionovich@keilab.io>"]
diff --git a/_primitives/_rust/kei-buddy/README.md b/_primitives/_rust/kei-buddy/README.md
new file mode 100644
index 0000000..48b6cde
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/README.md
@@ -0,0 +1,37 @@
+# kei-buddy
+
+**Maturity:** concept / scaffold — no business logic yet.
+
+## Purpose
+
+`kei-buddy` is the runtime crate that composes existing KeiSeiKit
+primitives (`kei-pet`, `kei-memory-sqlite`, `kei-cortex`,
+`kei-notify-telegram`) into a personal-assistant Telegram bot called
+KeiBuddy.
+
+On first contact the bot walks the user through an 11-state onboarding
+flow: name, tone, interests, hobbies, per-topic decomposition (specifics
+→ now-or-later → research preference → source selection), and digest
+schedule. After onboarding the bot enters ongoing conversation mode,
+drawing on the stored persona and memory.
+
+This crate provides the state-machine enum and skeleton driver. The
+onboarding FSM is ported from
+`keisei-marketplace/src/lib/keibuddy/chat-onboard.ts`.
+
+## Status
+
+Scaffold only. The `OnboardState` enum and `TransitionInput` struct are
+defined. All transition logic is stubbed (`next()` returns `self.clone()`).
+The binary entry point prints a placeholder message and exits 0.
+
+## Roadmap
+
+- **State-machine transition logic** — port `handleStep` from
+  `chat-onboard.ts`; wire per-state LLM-extract calls through kei-cortex.
+- **Memory binding** — persist scratchpad and finalised persona via
+  kei-memory-sqlite; implement `getChatState` / `setChatStep` equivalents.
+- **Persona binding** — read persona manifest via `kei-pet`; apply tone
+  overlay to outgoing replies.
+- **Transport binding** — wire kei-notify-telegram for outbound messages;
+  add a real Telegram webhook server (or kei-gateway adapter) for inbound.
diff --git a/_primitives/_rust/kei-buddy/src/bin/kei-buddy.rs b/_primitives/_rust/kei-buddy/src/bin/kei-buddy.rs
new file mode 100644
index 0000000..7511b45
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/bin/kei-buddy.rs
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: Apache-2.0
+//! kei-buddy binary entry point.
+//!
+//! Scaffold — the `serve` subcommand is a no-op stub until the
+//! Telegram webhook driver and memory layer are wired in.
+
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(
+    name = "kei-buddy",
+    about = "KeiBuddy personal-assistant bot (scaffold)",
+    version
+)]
+struct Cli {
+    #[command(subcommand)]
+    command: Command,
+}
+
+#[derive(Subcommand)]
+enum Command {
+    /// Start the Telegram webhook listener (not yet implemented).
+    Serve,
+}
+
+#[tokio::main]
+async fn main() {
+    let cli = Cli::parse();
+    match cli.command {
+        Command::Serve => {
+            println!("kei-buddy serve: not yet implemented, scaffold only");
+        }
+    }
+}
diff --git a/_primitives/_rust/kei-buddy/src/error.rs b/_primitives/_rust/kei-buddy/src/error.rs
new file mode 100644
index 0000000..72bf828
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/error.rs
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+//! Error type for kei-buddy operations.
+//!
+//! Three categories cover the three integration layers that will be
+//! wired in follow-up tasks: state-machine, memory store, transport.
+
+use thiserror::Error;
+
+/// Top-level error type for the KeiBuddy crate.
+///
+/// Variants will gain `#[from]` impls once the concrete dependencies
+/// (kei-memory-sqlite, kei-notify-telegram, kei-cortex) are wired.
+#[derive(Debug, Error)]
+pub enum BuddyError {
+    /// Error originating in the onboarding state machine.
+    #[error("state machine error: {0}")]
+    StateMachine(String),
+
+    /// Error originating in the memory persistence layer.
+    #[error("memory error: {0}")]
+    Memory(String),
+
+    /// Error originating in the Telegram (or other) transport layer.
+    #[error("transport error: {0}")]
+    Transport(String),
+}
diff --git a/_primitives/_rust/kei-buddy/src/lib.rs b/_primitives/_rust/kei-buddy/src/lib.rs
new file mode 100644
index 0000000..4f07e74
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/lib.rs
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: Apache-2.0
+//! kei-buddy — KeiBuddy personal-assistant Telegram bot scaffold.
+//!
+//! Concept-level crate. This file declares the public module surface.
+//! No business logic lives here; see individual modules.
+//!
+//! Module layout (Constructor Pattern — one file, one responsibility):
+//!   * `state`      — `OnboardState` enum + `next()` stub
+//!   * `transition` — `TransitionInput` input struct
+//!   * `error`      — `BuddyError` error type
+//!
+//! Follow-up tasks will add:
+//!   * LLM extraction via kei-cortex
+//!   * Memory persistence via kei-memory-sqlite
+//!   * Telegram webhook driver (kei-notify-telegram)
+
+pub mod error;
+pub mod state;
+pub mod transition;
+
+pub use error::BuddyError;
+pub use state::OnboardState;
+pub use transition::TransitionInput;
diff --git a/_primitives/_rust/kei-buddy/src/state.rs b/_primitives/_rust/kei-buddy/src/state.rs
new file mode 100644
index 0000000..0949a99
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/state.rs
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: Apache-2.0
+//! Onboarding state-machine enum.
+//!
+//! Ported from `keisei-marketplace/src/lib/keibuddy/chat-onboard.ts`.
+//! Each variant corresponds to one `Step` in the TypeScript source.
+//! Transitions are stubs; real logic arrives in a follow-up task.
+
+use serde::{Deserialize, Serialize};
+
+use crate::transition::TransitionInput;
+
+/// 11-state onboarding finite-state machine.
+///
+/// Mirrors the TypeScript `Step` union type exactly:
+/// `intro | ask_name | ask_tone | ask_interests | ask_hobbies |
+///  topic_specifics | topic_now_later | topic_research |
+///  topic_sources | ask_schedule | ready`
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum OnboardState {
+    /// Initial greeting — bot explains itself.
+    Intro,
+    /// Collecting user's display name.
+    AskName,
+    /// Collecting preferred communication tone.
+    AskTone,
+    /// Collecting list of interests.
+    AskInterests,
+    /// Collecting list of hobbies.
+    AskHobbies,
+    /// Per-topic: "what specifically interests you here?"
+    TopicSpecifics,
+    /// Per-topic: "discuss now or save for later?"
+    TopicNowLater,
+    /// Per-topic: "want ongoing source monitoring?"
+    TopicResearch,
+    /// Per-topic: "here are proposed sources, which to add?"
+    TopicSources,
+    /// Collecting digest schedule (morning/evening hours + timezone).
+    AskSchedule,
+    /// Onboarding complete; regular conversation mode.
+    Ready,
+}
+
+impl OnboardState {
+    /// Advance to the next state given user input.
+    ///
+    /// **Stub** — returns `self.clone()` until transition logic is ported.
+    /// Real implementation will extract fields via kei-cortex and follow
+    /// the per-topic queue logic from `chat-onboard.ts::handleStep`.
+    pub fn next(&self, _input: &TransitionInput) -> Self {
+        // TODO: port transition logic from chat-onboard.ts::handleStep
+        self.clone()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Smoke test: every variant round-trips through JSON serialisation.
+    #[test]
+    fn all_variants_serde_roundtrip() {
+        let variants = [
+            OnboardState::Intro,
+            OnboardState::AskName,
+            OnboardState::AskTone,
+            OnboardState::AskInterests,
+            OnboardState::AskHobbies,
+            OnboardState::TopicSpecifics,
+            OnboardState::TopicNowLater,
+            OnboardState::TopicResearch,
+            OnboardState::TopicSources,
+            OnboardState::AskSchedule,
+            OnboardState::Ready,
+        ];
+        for variant in &variants {
+            let json = serde_json::to_string(variant)
+                .unwrap_or_else(|e| panic!("serialize {:?}: {e}", variant));
+            let back: OnboardState = serde_json::from_str(&json)
+                .unwrap_or_else(|e| panic!("deserialize {:?} from {json:?}: {e}", variant));
+            assert_eq!(variant, &back, "round-trip failed for {:?}", variant);
+        }
+    }
+}
diff --git a/_primitives/_rust/kei-buddy/src/transition.rs b/_primitives/_rust/kei-buddy/src/transition.rs
new file mode 100644
index 0000000..2f2c540
--- /dev/null
+++ b/_primitives/_rust/kei-buddy/src/transition.rs
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: Apache-2.0
+//! Input struct for state-machine transitions.
+//!
+//! `TransitionInput` carries the raw user message and any structured
+//! fields that an LLM extractor has already parsed from it.
+//! In the scaffold phase the `extracted_fields` value is always `null`.
+
+use serde::{Deserialize, Serialize};
+
+/// Input to `OnboardState::next()`.
+///
+/// `user_text` is the verbatim Telegram message body.
+/// `extracted_fields` will hold the result of an LLM-extract call
+/// (e.g. `extractName`, `extractTone`, `extractList` from
+/// `chat-onboard-extract.ts`) once kei-cortex integration is wired.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TransitionInput {
+    /// Raw message text from the user, UTF-8, already trimmed.
+    pub user_text: String,
+
+    /// Structured fields extracted by an LLM call.
+    /// `serde_json::Value::Null` until kei-cortex integration is added.
+    pub extracted_fields: serde_json::Value,
+}