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capsule-memory

Cross-session memory. Reads local memory state and injects it into the system prompt through hooks. Part of Unicity AOS.

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Created 2026-03-16 · Updated 2026-10-05 · #18720 today
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astrid-capsule-memory

License: MIT OR Apache-2.0 MSRV: 1.94

Cross-session memory for Astrid OS agents.

In the OS model, this capsule is the persistent swap file. It carries context across session boundaries so the agent remembers what happened last time.

How it works

Hooks into prompt_builder.v1.hook.before_build. On each prompt assembly cycle:

  1. Reads .astrid/memory.md from the workspace via the VFS
  2. Wraps the content in a # Memory section
  3. Publishes an appendSystemContext hook response on the per-request response topic

If the file is missing or empty, the capsule is a no-op.

Size cap

Agent-written content can grow without limit (unlike human-authored AGENTS.md), so a 32KB hard cap prevents unbounded context window consumption. Content beyond the limit is truncated at a UTF-8 character boundary with a [Memory truncated] marker.

Read-only

This capsule handles the read/inject side only. The agent writes to .astrid/memory.md using existing filesystem tools (write_file, replace_in_file) from astrid-capsule-fs. No new tools needed.

Development

cargo build --target wasm32-unknown-unknown --release

License

Dual-licensed under MIT and Apache 2.0.

Copyright (c) 2025-2026 Joshua J. Bouw and Unicity Labs.