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OSTK
SYSTEM_ARCHITECTURE // 02

The ostk Stack

ostk is a set of independently useful local components. Use the pieces that match your workflow; support and integration depth vary by model, harness, provider route, and platform.

The kernel owns local project substrate and kernel-mediated operations. Recall indexes configured local sources. Cache is an optional context-efficiency route. libostk supports client integration. None of those components makes every harness expose the same guarantees.

HOW_TO_READ_THE_STACK

ostk kernel

Owns project state and the guarantees attached to kernel-mediated operations.

ostk-recall

Indexes configured local sources so a new model or harness can recover relevant context.

ostk-cache

Adds optional, route-specific context-efficiency behavior; it is not the continuity boundary.

libostk

Supports client integrations. Available capabilities and depth vary by client and route.

STACK_MATRIX // COMPARISON

COMPONENT LICENSE INTERFACE / SOCKET CORE MECHANISM
ostk (kernel) AGPL-3.0 CLI & Daemon
ostk boot / run 		Landlock/Seatbelt process sandbox limits, WAL audit logging, OCC check constraints.
ostk-recall AGPL-3.0 Stdio MCP / Socket
.ostk/recall.sock 		LanceDB vector store + Tantivy BM25, fastembed-rs reranker, debounce file watcher loop.
ostk-cache AGPL-3.0 Transparent HTTP Proxy
localhost:8080 		Anthropic/OpenAI wire proxy, synthetic projection mutations, local soft-cap tiering (A-D).
libostk MIT JSON-RPC 2.0 over
.ostk/ostk.sock 		Inode-based log rotation tracking, GPG/Ed25519 signature checks, custom platform envelope parsing.

1. ostk Kernel & CLI

AGPL-3.0 LICENSE

The central local coordinator. ostk exposes the System ABI, owns project substrate, and can apply OS-native containment such as Landlock (Linux) or Seatbelt (macOS) on supported launch paths. Native client tools are not transparently intercepted.

Kernel-mediated dispatches append local audit rows. CAS file mutations are record-first and fail closed if their audit row cannot be written; shell audit is best-effort after execution. Rows are hash-chained and are Ed25519-signed when a signing key is available.

KERNEL SPECS
  • Isolation: Landlock / Seatbelt
  • Journal: journal.jsonl (WAL)
  • Coordination: OCC gen_table
  • Identity: Ed25519 / DSSE, legacy GPG
View kernel docs →

2. ostk-recall Memory

AGPL-3.0 LICENSE

When a model or harness changes, relevant project context should not disappear with it. ostk-recall builds a local hybrid index over configured sources so supported clients can search the same owned corpus.

The database is updated in real-time by a socket file watcher listening on recall.sock. Changes are debounced in userspace to prevent performance degradation during batch file writes. Queries are routed through a fastembed-rs reranking model locally, delivering precise context matches to agent systems.

MCP TOOLS
  • recall_search
  • recall_view
  • recall_scan
  • recall_watch
  • recall_status
View recall docs →

3. ostk-cache Proxy

AGPL-3.0 LICENSE

ostk-cache is an optional local proxy for compatible provider routes. It can preserve stable request regions and apply route-specific context-efficiency behavior; provider caching and measured savings remain dependent on the selected model, API, and harness.

The proxy operates across 4 dynamic reduction tiers (A to D) based on response lengths and confidence metrics. In Rebuild and RebuildKernel modes, the cache coordinates with the daemon via IPC to rebuild projections and invalidate outdated blocks whenever the codebase changes.

SPECIFICATIONS
  • Wire formats: Anthropic, OpenAI
  • Default proxy port: 8080
  • Audit logging: .ostk/memory/ledger.jsonl
  • Invalidation: IPC signals
View cache docs →

4. libostk Client Library

MIT LICENSE

libostk is the foundational client-side layer. Written in pure Rust with lightweight language wrappers, it provides a stable interface to negotiate capability scopes with the ostk daemon. By making libostk completely MIT licensed, developers can build custom integrations inside closed-source IDE overlays or proprietary automation scripts without licensing restrictions.

Its audit_tail driver tracks inode changes so a client can reopen a journal after rotation, truncation, or replacement. That improves continuity for supported consumers without turning the client library into a universal delivery guarantee.

INTEGRATIONS
  • Windmill pipelines
  • Discord bot dispatch
  • Windmill action runners
  • Windmill/Cursor extensions
View libostk docs →