diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..2ada1b8
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,118 @@
+# AGENTS.md — tines
+
+Instructions for AI agents working on **tines**: opportunistic shared memory
+for mostly-offline robots. Read this before touching code.
+
+## What tines is
+
+Small robots collect facts about the world while mostly offline. When two of
+them happen to meet in range, they swap what they know so each one's picture of
+the world improves. No robot depends on receiving anything, but there is no
+reason not to share.
+
+`tines` is the library that does this: a store of timestamped-by-age
+observations, a belief layer derived from them, and a delay-tolerant exchange
+protocol over any datagram link. Read the full intent, goals, anti-goals, and
+architecture in the **spec first**:
+
+- **Spec (authoritative):** `docs/superpowers/specs/2026-10-16-tines-design.md`
+- **Implementation plan (how to build it):** `docs/superpowers/plans/2026-10-16-tines-core-and-sim.md`
+
+The plan argues from the spec. Where the plan is silent, the **spec rules**.
+Do not edit the spec or the plan — they are design history, not source.
+
+## Architecture (three layers)
+
+```
+ memory — "my priors": beliefs per topic, derived from storage under a policy
+ storage — append-only log of raw observations; local trimming policy
+ comms   — contact-driven exchange of observations; transport trait + adapters
+```
+
+Only observations cross the wire. Memory is a pure function of storage plus a
+policy and is never transmitted. See the spec's "Architecture" section for the
+`Observation`, `Store`, `BeliefPolicy`, `Transport`, and exchange protocol
+details.
+
+## Workflow
+
+This project is built by working the implementation **task-by-task, in order**.
+Each task is TDD: write the failing test → see it fail → implement → see it
+pass → commit. Do not skip ahead — later tasks depend on the exact names and
+signatures earlier tasks produce. Tick the task checkboxes as you go.
+
+For each task:
+
+1. Read its section in the plan.
+2. Implement to the interfaces the plan pins; don't invent new public names.
+3. Before committing, run:
+   - `cargo test --workspace`
+   - `cargo clippy --workspace -- -D warnings`
+   - `sh scripts/check-no-std.sh` (for any core change)
+4. Commit with the **exact** message the plan gives for that task.
+
+The `Node` facade is core, not application glue: an application on any target
+should only need to construct a `Node` with its `NodeId`, store, and transport,
+call `poll()` in its loop, and `observe()` when it sees something.
+
+## Hard constraints (non-negotiable in `tines-core`)
+
+- `tines-core` is `#![no_std]`; `alloc` is a cargo feature (default on). With
+  `--no-default-features` it must build for `thumbv7em-none-eabihf`. Only
+  `MemStore` may require `alloc`.
+- No async, no threads, no I/O, and no panic on untrusted input in core. Every
+  frame from the wire is untrusted: malformed bytes are dropped, never
+  unwrapped.
+- Core never maps a transport `Addr` to a `NodeId`; every frame carries the
+  sender's `NodeId`.
+- Identity hash covers `(observer, seq, topic, payload)` **only**. `age_ms` and
+  `observed_at` are excluded.
+- `Node::next_seq()` must be persisted by the application across reboots
+  (`boot_count << 32 | counter`); a repeated seq after reboot collides in the
+  ID hash and must dedupe silently (`insert` returns `Ok(false)`).
+- `NodeId = [u8; 16]`, `ObservationId = [u8; 16]`, `Tick = u64` (local
+  monotonic ms, supplied on every call).
+
+### Review Focus (each pinned to a task with a test)
+
+1. Reused `seq` after reboot → store dedupes, `insert` returns `Ok(false)`. (Task 3)
+2. Oversized `topic`/`payload` at `observe()` → `Err(TooLarge)`, never truncate/panic. (Task 10)
+3. Garbage frames → dropped, no panic, no store change. (Tasks 2, 6, 7, 13)
+4. Frame from an address with no prior `Contact` → treated as implicit contact. (Task 7)
+5. Tick going backwards → age saturates at stored value, never underflow. (Task 3)
+
+### Compile-time constants (`tines-core/src/consts.rs`)
+
+`MAX_TOPIC=64`, `MAX_PAYLOAD=1024`, `MAX_PEERS=8`, `SUMMARY_BYTES=512`,
+`BLOOM_K=3`, `SUMMARY_INTERVAL_MS=2000`, `REASSEMBLY_TIMEOUT_MS=5000`,
+`SEND_QUEUE_CAP=256`, `MAX_FRAME=1500`. Match the exact values above.
+
+## Crate layout and current state
+
+```
+tines/
+  tines-core/   no_std core: Observation, Store/Transport/BeliefPolicy traits,
+                exchange state machine, Node facade, in-memory store, reference
+                policies
+  tines-sim/    std: simulator, contact traces, convergence property tests
+```
+
+State of the plan (`docs/superpowers/plans/...tines-core-and-sim.md`):
+
+- **Done & committed:** Tasks 1–6 (workspace + Observation identity, wire
+  frames, Store/MemStore, salted Bloom summary, Transport trait, fragmentation
+  and reassembly).
+- **Implemented, not committed:** Task 7 — `tines-core/src/exchange.rs` plus the
+  `lib.rs` changes. Commit it with the Task 7 message before starting Task 8.
+- **Pending:** Task 8 (belief policies), 9 (`PairTransport` test helper),
+  10 (Node facade + `tests/pair.rs` convergence test), 11–13 (simulator world,
+  harness, property tests), 14 (`scripts/ci.sh` + README).
+
+The `std` simulator is the test harness for the protocol; its convergence and
+order-independence property tests are the main correctness evidence.
+
+## Not in scope for this plan
+
+`tines-udp`, `tines-sqlite`, `tines-cli`, and `tines-serial` belong to a second
+plan. Do not start them here. The README lives in Task 14 of the plan — it will
+be produced by the implementer; do not author it separately.