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+## The Jerboa Language — Quick Reference
+
+Jerboa is a Scheme dialect built on Chez Scheme. It is Gerbil-inspired but its own language. **All user-facing code is `.ss` files. Never write `.sls` files for the user** — those are internal implementation files.
+
+### File Structure
+
+Every Jerboa file looks like this:
+
+```scheme
+(import (jerboa prelude))    ;; ONE import gives you the ENTIRE language
+;; Optional extra imports for modules NOT in the prelude:
+;; (import (std net request))
+
+(def (my-function x y)
+  (+ x y))
+
+(displayln (my-function 1 2))
+```
+
+Run with: `jerboa run file.ss`
+
+**NEVER** write `(library ...)` forms — that's `.sls` internal syntax.
+
+### Reader Syntax Extensions
+
+```
+[...]                → plain parentheses — same as Gerbil and Chez Scheme
+{method obj args}    → (~ obj 'method args)  — method dispatch
+name:                → keyword #:name
+:std/sort            → (std sort)        — Gerbil-style module path
+#<<END ... END       → heredoc string
+```
+
+Square brackets `[...]` are interchangeable with `(...)`, exactly like Gerbil and stock Chez Scheme. You can freely use them in bindings, match clauses, and anywhere you'd use parentheses:
+```scheme
+;; All of these are correct:
+(let ([x 1] [y 2]) (+ x y))
+(for/collect ([x (in-range 5)]) (* x x))
+(match val ([list a b] (+ a b)))
+(cond [(> x 0) "positive"] [else "non-positive"])
+```
+
+### CRITICAL: Things That DO NOT EXIST in Jerboa/Chez
+
+Claude frequently hallucinates these from Gerbil, Gambit, Racket, or R7RS training data.
+**NONE of them are real in Jerboa/Chez. STOP and use the correct form.**
+
+#### AI Compatibility Aliases (these now work in the prelude)
+The following names from other Scheme dialects are aliased in `(jerboa prelude)`:
+- `hash-has-key?` → `hash-key?` (Racket)
+- `hash-table-set!` → `hash-put!` (Racket)
+- `directory-exists?` → `file-directory?` (Gambit)
+- `eql?` → `eqv?` (Common Lisp)
+- `random-integer` → `random` (Gambit)
+- `read-line` → `get-line` wrapper (Gambit) — works with or without port arg
+- `force-output` → `flush-output-port` wrapper (Gambit) — works with or without port arg
+- `string-map` → char-level map (Racket/R7RS) — `(string-map f str)`
+
+#### Hallucinated Functions (still do NOT exist)
+- `symbol<?` — use `(lambda (a b) (string<? (symbol->string a) (symbol->string b)))`
+- `string-contains?` — use `(string-contains str sub)` (returns index or #f, NOT boolean)
+- `define-struct` — use `(defstruct name (fields ...))`
+- `raise` with a string — use `(error 'who "message" irritants ...)`
+- `environment-bound?` — Gerbil-only. No direct Chez equivalent
+
+#### Gerbil/Gambit-isms (from training data — wrong in Jerboa)
+- `time->seconds` — use `(time-second (current-time))` for epoch seconds
+- `thread-sleep!` — Gambit. Use `(sleep (make-time 'time-duration 0 seconds))`
+- `thread-yield` — no Chez equivalent. Use `(sleep (make-time 'time-duration 0 0))` as workaround
+- `path-expand` with 2 args — Gerbil takes `(path-expand rel base)`. Jerboa takes 1 arg. Use `(path-join base rel)` for 2-arg version
+- `process-status` — Gerbil. Use `(std misc process)` API in Jerboa
+- `user-info-home` — Gerbil. Use `(getenv "HOME")`
+- `the-environment` — Gerbil. Use `(interaction-environment)` in Chez
+- `condition/report-string` — Gerbil. Use `(with-output-to-string (lambda () (display-condition c)))`
+- `make-class-type` — Gerbil. Use `(defstruct ...)` or `(defclass ...)` in Jerboa
+- `string-subst` — Gerbil. Not in prelude. Use `(string-replace str old new)` or implement manually
+- `open-fd-pair` — Gambit. Does not exist in Chez; requires different API
+
+#### R6RS/Racket-isms (wrong variant)
+- `make-equal-hashtable` — R6RS. Use `(make-hash-table)` from Jerboa prelude
+- `arithmetic-shift` — Racket. Use `(bitwise-arithmetic-shift n k)` or `(ash n k)` in Chez
+- `pregexp-match` — Racket. Use `(std text regex)` or `(std pregexp)` API in Jerboa
+
+### CRITICAL: Common Arity Mistakes
+
+- `(list-of? pred)` → returns a PREDICATE. It takes 1 arg. Use: `((list-of? number?) lst)`
+- `(maybe pred)` → returns a PREDICATE. It takes 1 arg. Use: `((maybe string?) val)`
+- `(in-range end)` or `(in-range start end)` or `(in-range start end step)` — NOT `(in-range start step end)`
+- `(hash-ref ht key)` or `(hash-ref ht key default)` — NOT `(hash-ref key ht)`
+- `(string-split str delimiter)` where delimiter is a CHAR: `(string-split "a,b" #\,)`
+- `(make-rwlock)` — takes **0 args**, NOT `(make-rwlock 'name)` (Gerbil takes a name; Jerboa does not)
+- `(path-expand path)` — takes **1 arg**, NOT `(path-expand rel base)` (Gerbil takes 2; use `path-join` for 2-arg)
+- `(sort list predicate)` — Jerboa `(std sort)`/prelude order. Raw Chez `sort` is predicate-first, but Jerboa-facing code should use list first.
+
+### Core Forms (all from `(import (jerboa prelude))`)
+
+#### Definitions
+```scheme
+(def x 42)                              ;; variable
+(def (f x y) (+ x y))                  ;; function
+(def (f x (y 10)) body)                ;; optional param with default
+(def (f x . rest) body)                ;; rest args
+(def* f ((x) ...) ((x y) ...))         ;; multi-arity
+(defrule (name pat) template)           ;; macro
+```
+
+#### Data Structures
+```scheme
+(defstruct point (x y))                ;; → make-point, point?, point-x, point-y, point-x-set!
+(defstruct (circle shape) (radius))    ;; inheritance (single only)
+(defmethod (area (self circle)) body)  ;; method on type
+(~ obj 'method arg ...)                ;; dispatch (or {method obj arg ...})
+(defrecord person (name age))          ;; struct + pretty-print + ->alist
+(define-enum color (red green blue))   ;; → color-red, color?, color->name
+```
+
+#### Pattern Matching
+```scheme
+(match value
+  (42 "exact")                          ;; literal
+  ((list a b c) (+ a b c))             ;; list destructure
+  ((cons h t) h)                        ;; pair
+  ((? number?) "num")                   ;; predicate
+  ((? string? s) (string-upcase s))    ;; predicate + bind
+  ((and (? number?) (? positive?)) "positive number")
+  ((or "yes" "y") #t)
+  ((=> string->number n) n)            ;; view pattern
+  (n (where (> n 0)) "positive")       ;; guard
+  (_ "default"))                        ;; wildcard
+```
+
+#### Error Handling
+```scheme
+(try expr (catch (e) handler) (finally cleanup))
+(try expr (catch (error? e) handler))
+(unwind-protect body cleanup)
+(with-resource (var init cleanup) body)
+```
+
+#### Result Type (Rust-inspired ok/err)
+```scheme
+(ok 42)  (err "bad")  (ok? r)  (err? r)
+(unwrap (ok 42))         ;; → 42 (raises on err)
+(unwrap-or (err "x") 0)  ;; → 0
+(map-ok f result)  (map-err f result)
+(and-then result f)       ;; monadic bind
+(try-result expr)         ;; exceptions → (err condition)
+(try-result* expr)        ;; exceptions → (err "message string")
+(sequence-results list-of-results)  ;; → (ok list) or first (err)
+(->? (ok 10) (+ 5) (* 2))  ;; → (ok 30), short-circuits on err
+```
+
+#### Iterators
+```scheme
+(for ((x (in-range 5))) (displayln x))
+(for/collect ((x (in-range 5))) (* x x))           ;; → (0 1 4 9 16)
+(for/fold ((sum 0)) ((x (in-range 10))) (+ sum x)) ;; → 45
+(for/or ((x lst)) (and (pred? x) x))               ;; first truthy
+(for/and ((x lst)) (pred? x))                       ;; all truthy
+
+;; Iterators: in-list, in-vector, in-string, in-range, in-hash-keys,
+;; in-hash-values, in-hash-pairs, in-naturals, in-indexed,
+;; in-port, in-lines, in-chars, in-bytes, in-producer
+```
+
+#### Threading Macros
+```scheme
+(-> x (f a) (g b))       ;; thread first: (g (f x a) b)
+(->> x (f a) (g b))      ;; thread last:  (g b (f a x))
+(as-> x v (f v) (g v))   ;; named
+(some-> x (f) (g))       ;; short-circuit on #f
+(cond-> x test (f) t2 (g))  ;; conditional steps
+(->? (ok x) (f) (g))     ;; result-aware thread first
+```
+
+#### Ergo Typing
+```scheme
+(: expr pred?)                    ;; checked cast
+(using (p (make-point 1 2) : point?)
+  (+ p.x p.y))                   ;; dot-access → (point-x p) etc.
+((list-of? number?) '(1 2 3))    ;; predicate factory → #t
+((maybe string?) #f)              ;; accepts #f or string → #t
+```
+
+#### Hash Tables
+```scheme
+(def ht (make-hash-table))
+(hash-put! ht "key" "val")
+(hash-ref ht "key")              ;; error if missing
+(hash-ref ht "key" "default")    ;; with default
+(hash-get ht "key")              ;; → val or #f
+(hash-key? ht "key")             ;; → #t/#f
+(hash-remove! ht "key")
+(hash->list ht)  (hash-keys ht)  (hash-values ht)
+(hash-for-each (lambda (k v) ...) ht)
+(list->hash-table '(("a" . 1) ("b" . 2)))
+```
+
+#### Strings
+```scheme
+(string-split "a,b,c" #\,)       ;; → ("a" "b" "c")  NOTE: char delimiter
+(string-join '("a" "b") ",")     ;; → "a,b"
+(string-trim "  hi  ")           ;; → "hi"
+(string-prefix? "he" "hello")    ;; → #t
+(string-suffix? "lo" "hello")    ;; → #t
+(string-contains "hello" "ell")  ;; → 1 (index, not boolean!)
+(string-empty? "")               ;; → #t
+(str "age: " 42 "!")             ;; → "age: 42!" (auto-coerce)
+```
+
+#### Lists
+```scheme
+(flatten '(1 (2 (3))))    ;; → (1 2 3)
+(unique '(1 2 2 3))       ;; → (1 2 3)
+(take lst n)  (drop lst n)  (take-last lst n)  (drop-last lst n)
+(every pred lst)  (any pred lst)  (filter-map f lst)
+(group-by f lst)  (zip lst1 lst2)  (frequencies lst)
+(partition pred lst)  (interleave l1 l2)  (mapcat f lst)
+(distinct lst)  (keep f lst)  (split-at lst n)
+(append-map f lst)  (snoc lst elem)
+```
+
+#### Functional Combinators
+```scheme
+(compose f g)  (comp f g)       ;; (f (g x))
+(partial f arg ...)              ;; partial application
+(complement pred)  (negate pred) ;; logical not
+(identity x)  (constantly v)     ;; basic combinators
+(curry f arg)  (flip f)          ;; currying, arg swap
+(conjoin p1 p2)  (disjoin p1 p2) ;; predicate AND/OR
+(juxt f g)                        ;; → (lambda (x) (list (f x) (g x)))
+(cut f <> y)                      ;; SRFI-26 partial: (lambda (x) (f x y))
+```
+
+#### JSON
+```scheme
+(string->json-object "{\"key\":\"val\"}")  ;; → hash table
+(json-object->string ht)                    ;; → JSON string
+(read-json port)  (write-json obj port)
+```
+
+#### CSV
+```scheme
+(csv->alists "name,age\nAlice,30")  ;; → (((name . "Alice") (age . "30")))
+(read-csv-file "data.csv")          ;; → list of row lists
+(write-csv-file "out.csv" rows)
+```
+
+#### DateTime
+```scheme
+(datetime-now)  (datetime-utc-now)
+(make-datetime 2026 3 27 12 0 0)
+(parse-datetime "2026-03-27T12:00:00Z")
+(datetime->iso8601 dt)  (datetime->epoch dt)
+(datetime-add dt duration)  (datetime-diff dt1 dt2)
+(datetime<? dt1 dt2)  (day-of-week dt)  (leap-year? 2024)
+```
+
+#### Paths
+```scheme
+(path-join "/home" "user" "f.txt")  ;; → "/home/user/f.txt"
+(path-directory "/a/b/f.txt")       ;; → "/a/b"
+(path-extension "file.txt")         ;; → "txt"
+(path-absolute? "/home")            ;; → #t
+```
+
+#### File I/O
+```scheme
+(read-file-string "f.txt")         ;; → entire file
+(read-file-lines "f.txt")          ;; → list of lines
+(write-file-string "f.txt" "data")
+```
+
+#### Pretty Printing
+```scheme
+(pp expr)  (pp-to-string expr)  (pprint expr)
+```
+
+#### Formatting
+```scheme
+(format "~a is ~a" "Alice" 30)  ;; → "Alice is 30"
+(printf "x = ~a\n" 42)
+(displayln "hello" " " "world")
+```
+
+#### Anaphoric / Conditional Binding
+```scheme
+(awhen (find x) (use it))          ;; binds result to `it`
+(aif (find x) (use it) (default))
+(when-let (x (find y)) (use x))
+(if-let (x (find y)) (use x) (default))
+```
+
+#### Loops
+```scheme
+(while test body ...)
+(until test body ...)
+(dotimes (i 10) body ...)   ;; 0..9
+```
+
+#### Misc Sugar
+```scheme
+(assert! (> x 0))  (assert! (> x 0) "message")
+(alist (name "Alice") (age 30))  ;; → ((name . "Alice") (age . 30))
+(let-alist data (name age) body)
+```
+
+### What's NOT in the Prelude (requires separate import)
+
+```scheme
+(import (std net request))      ;; HTTP client
+(import (std net httpd))        ;; HTTP server
+(import (std db sqlite))        ;; SQLite
+(import (std actor))            ;; Actor system
+(import (std async))            ;; Async/await
+(import (std crypto digest))    ;; SHA, MD5
+(import (std text regex))       ;; Regex
+(import (std text xml))         ;; XML
+(import (std text yaml))        ;; YAML
+(import (std os env))           ;; Environment variables
+(import (std os signal))        ;; Signal handling
+(import (std security sandbox)) ;; Sandboxing
+```
+
+### Chez Scheme Conflicts (handled by prelude)
+
+The prelude shadows these Chez builtins with Jerboa versions:
+`make-hash-table`, `hash-table?`, `sort`, `sort!`, `printf`, `fprintf`,
+`path-extension`, `path-absolute?`, `with-input-from-string`,
+`with-output-to-string`, `iota`, `1+`, `1-`, `partition`,
+`make-date`, `make-time`
+
+All standard Chez Scheme is still available — the prelude just re-exports
+improved versions of the above.
+
+---
+
+## Repository Boundaries
+
+When working in a Jerboa project, **ONLY modify files in the current repo** unless the user explicitly names another path.
+
+Common sibling repos that exist but must NOT be touched without explicit instruction:
+- `~/mine/jerboa-emacs` — **NEVER touch**. Another model owns it.
+- `~/mine/jerboa-mcp` — Legacy node MCP, superseded. The active MCP server now lives in THIS repo at `mcp/` + `data/`. Don't modify the legacy repo unless told.
+- `~/mine/jerboa-shell` — Only modify when user explicitly says to work there.
+- `~/mine/gerbil-mcp` — **NEVER touch**. Deprecated.
+- `~/mine/gerbil-orig` — Read-only reference for upstream Gerbil. Never modify.
+
+If a user instruction mentions a file path, use EXACTLY that path. Do not substitute a similar-looking path from another repo.
+
+### Never Reference Sibling Checkouts in Build Files
+
+Build files (Makefile, shell scripts, CI config) must **never** resolve a
+dependency via a relative sibling path (`../jerboa-foo`) or an absolute
+`~/mine/jerboa-foo` path. That layout is specific to this one machine —
+other users and CI do not have it. Always vendor instead: fetch/clone the
+dependency into `vendor/` (or this repo's equivalent) at build time, or use
+a pinned-release fetch script, so the build is reproducible without
+assuming any sibling checkout exists.
+
+A sibling-path fallback is not just a portability bug: it can silently
+substitute a full alternate source tree (build config, embedded data,
+secrets) for the vendored one, with no equivalent safety default, changing
+what actually gets built without any indication. If you find one
+(`grep -rn '\.\./jerboa\|~/mine/jerboa'` over Makefiles/scripts), remove it
+and vendor properly instead.
+
+---
+
+## Build & Verification
+
+After modifying any `.ss` or `.sls` (Jerboa Scheme) source files, always run the build command and fix any errors before moving on. Common issues include: missing imports, wrong function names, and duplicate definitions.
+
+### Stale Artifacts
+
+If edits seem to have no effect after `make build`, delete stale compiled files:
+```bash
+find lib -name "*.so" -delete && find lib -name "*.wpo" -delete && make build
+```
+Run `jerboa_stale_static` to detect stale `.so` files before debugging "why doesn't my edit work?".
+
+## Pre-commit Requirements
+
+**ALWAYS** run a clean build **before** committing any code to this repository. Pick the right target for the *current* platform:
+
+- **Linux**: run `make docker-build` — the Docker image must build cleanly against the full musl-static release pipeline.
+- **macOS / FreeBSD / other**: run `make binary` — the native local build must succeed. Do **not** run `make docker-build` here; Docker on non-Linux hosts is slow and not the canonical pipeline for those platforms.
+
+Do not commit if the build fails.
+
+## Act First, Read Less
+
+When making changes, read only what you need to make the edit, then make it.
+Do not read more than 3 files before acting. Do not re-read files you already
+read. Do not verify things you already know. If you have enough context to make
+a change, make it. The user will interrupt you if you are wrong.
+
+## Jerboa MCP Tools — MANDATORY Usage
+
+Jerboa is a niche Scheme dialect with limited training data. **Never guess — always verify** with MCP tools. Tool descriptions are available at runtime via the MCP server; this section covers **when** and **why** to use each tool.
+
+### MANDATORY Workflow Order (for writing new code)
+
+1. **`jerboa_howto`** — BEFORE writing code, search cookbook for verified patterns
+2. **`jerboa_module_exports`** / **`jerboa_function_signature`** — confirm APIs exist and check arities
+3. Write the code
+4. **`jerboa_verify`** — combined syntax + compile + lint + arity + duplicate check (use instead of individual tools)
+5. **`jerboa_security_scan`** — for code involving FFI, shell commands, or file I/O
+
+### Essential Tools (use proactively)
+
+| When | Tool |
+|---|---|
+| Before writing ANY Jerboa code | `jerboa_howto` — cookbook has verified patterns with correct imports |
+| Check what a module exports | `jerboa_module_exports` — never guess function names |
+| Check function arity/args | `jerboa_function_signature` — prevents wrong-arg-count errors |
+| Validate your code | `jerboa_verify` — one-stop syntax+compile+lint+arity check |
+| Test expressions interactively | `jerboa_eval` — use `imports` param for modules, `env` for FFI paths |
+| Persistent interactive testing | `jerboa_repl_session` — maintains state across evaluations |
+| Debug an error message | `jerboa_explain_error` + `jerboa_error_fix_lookup` |
+| Understand unfamiliar code | `jerboa_file_summary` + `jerboa_document_symbols` |
+| Find where something is defined | `jerboa_find_definition` — source file, module, kind, arity |
+| Search for symbol by substring | `jerboa_apropos` or `jerboa_smart_complete` |
+| Build the project | `jerboa_build_and_report` or `jerboa_make` — prefer over bash `make` |
+| Run tests | `jerboa_run_tests` — prefer over ad hoc shell test invocations |
+| Check for stale .so artifacts | `jerboa_stale_static` — common cause of "edit has no effect" |
+| Macro expansion | `jerboa_expand_macro` / `jerboa_trace_macro` |
+| Inspect struct/class types | `jerboa_class_info` — fields, inheritance, constructor signature |
+| FFI work | `jerboa_ffi_scaffold` / `jerboa_ffi_type_check` / `jerboa_ffi_null_safety` |
+| Port Gerbil code | `jerboa_migration_check` + `jerboa_translate_scheme` |
+| Detect paren imbalance | `jerboa_check_balance` — use BEFORE `make build` after deep edits |
+| Full project audit | `jerboa_project_health_check` — balance, exports, cycles, duplicates |
+| Security audit | `jerboa_security_audit` + `jerboa_import_policy_check` |
+| Static build audit | `jerboa_static_symbol_audit` + `jerboa_boot_library_audit` |
+| Explore a module | `jerboa_module_catalog` (replaces multiple `jerboa_doc` calls) |
+| Look up any symbol | `jerboa_doc` — type, arity, qualified name, related symbols |
+| Read stdlib source | `jerboa_stdlib_source` — see internal implementations |
+
+### Cookbook & Knowledge Management
+
+- **`jerboa_howto`** / **`jerboa_howto_get`**: Search and retrieve verified recipes
+- **`jerboa_howto_add`**: Save new patterns to cookbook (MANDATORY when you discover something non-trivial)
+- **`jerboa_howto_run`** / **`jerboa_howto_verify`**: Validate recipes still work
+- **`jerboa_error_fix_add`**: Save error→fix mappings for common mistakes
+- **`jerboa_anti_pattern_lookup`**: Search reusable local-model mistakes and failed strategies
+
+**The knowledge base is `data/*.sexp` in THIS repo**, embedded into `jmcp` at build time. The write tools above edit it live — the server reads `data/` from disk first, with the embedded copy as fallback (`JERBOA_MCP_REPO` points every client at this repo). When you add a stdlib/language feature, also update `data/` (a cookbook recipe + `api-signatures.sexp` + `changelog.sexp`) and **commit it**. Run `make jmcp` (or `make jmcp-portable`) only to refresh the embedded copy shipped in portable binaries.
+
+### Code Generation & Refactoring
+
+`jerboa_rename_symbol`, `jerboa_balanced_replace`, `jerboa_wrap_form`, `jerboa_splice_form`, `jerboa_scaffold_test`, `jerboa_generate_module`, `jerboa_translate_scheme`, `jerboa_project_template`, `jerboa_httpd_handler_scaffold`, `jerboa_db_pattern_scaffold`, `jerboa_actor_ensemble_scaffold`
+
+### Feature Suggestions
+
+- **`jerboa_list_features`** / **`jerboa_suggest_feature`** / **`jerboa_vote_feature`**: Track and submit tooling improvement ideas
+
+---
+
+## MANDATORY: Save What You Learn
+
+Jerboa is niche — every non-trivial pattern you discover prevents future sessions from re-discovering it.
+
+### Save to cookbook (`jerboa_howto_add`) whenever you:
+- Discover a working pattern through `jerboa_eval` or trial-and-error
+- Figure out correct imports, arities, or calling conventions that weren't obvious
+- Find a workaround for a Jerboa quirk or undocumented behavior
+
+**Before saving**: check `jerboa_howto` to avoid duplicates. **Do NOT save**: trivial one-liners, project-specific logic, or existing recipes.
+
+**Recipe format**: `id` (kebab-case), `tags` (4-6 search keywords incl. module name), `imports` (all required), `code` (complete working example), `notes` (gotchas/alternatives).
+
+### Save anti-patterns (`data/anti-patterns.sexp`) whenever you:
+- See a plausible local-model strategy that failed verification
+- Find a weak verifier pattern that allowed false success
+- See a repeated repair loop, such as broad-reading after a concrete error
+- Find a generic runtime mistake, such as missing lower-bound checks before vector access
+
+**Before saving**: check `jerboa_anti_pattern_lookup` to avoid duplicates. If none exists, call `jerboa_anti_pattern_add`; only edit `data/anti-patterns.sexp` directly if the writer tool is unavailable. Save the normalized reusable mistake, not the whole trace or benchmark name.
+
+**Anti-pattern format**: `id`, `title`, `kinds`, `severity`, `tags`, `pattern`, `avoid`, `advice`, `tools`.
+
+### Save error fixes (`jerboa_error_fix_add`) whenever you:
+- See exact compiler/runtime/verifier text with a repeatable repair
+- Hit an error that `jerboa_failure_advisor` should classify better next time
+- Debug a local-model generated-code failure where a short diagnosis prevents another failed iteration
+
+**Before saving**: check `jerboa_error_fix_lookup` with the exact error text. **Do NOT save**: one-off project business-logic mistakes.
+
+**Error-fix format**: `id`, `pattern`, `fix`; optional `type`, `explanation`, `code_example`.
+
+### Suggest tooling improvements (`jerboa_suggest_feature`) whenever you:
+- Make multiple sequential tool calls that could be one tool
+- Fall back to bash because an MCP tool is missing or insufficient
+
+**Before suggesting**: check `jerboa_list_features`; vote with `jerboa_vote_feature` if it already exists.
+
+### Save Discoveries Mechanisms
+- **`/save-discoveries` skill**: invoke anytime to review session and save recipes, anti-patterns, error fixes, feature suggestions, and security patterns
+- **PreCompact hook**: add `PreCompact` hook with `type: "prompt"` in `.claude/settings.json` to auto-save before context compaction
+
+---
+
+## Common Workflows
+
+- **Write new code**: `jerboa_howto` -> `jerboa_module_exports` -> write code -> `jerboa_verify` -> `jerboa_security_scan`
+- **Debug an error**: `jerboa_explain_error` -> follow suggested tools -> `jerboa_howto` for fix patterns
+- **Understand unfamiliar code**: `jerboa_file_summary` -> `jerboa_document_symbols` -> `jerboa_module_deps`
+- **Refactor a module**: `jerboa_check_exports` -> `jerboa_find_callers` -> `jerboa_rename_symbol` -> `jerboa_check_import_conflicts`
+- **Build project**: `jerboa_build_conflict_check` -> `jerboa_make` -> `jerboa_build_and_report`
+- **Port from Gerbil**: `jerboa_migration_check` -> `jerboa_translate_scheme` -> `jerboa_verify` -> `jerboa_check_syntax`
+- **Audit project quality**: `jerboa_verify` -> `jerboa_lint` -> `jerboa_dead_code` -> `jerboa_dependency_cycles`
+- **Debug a crash**: `jerboa_stale_static` -> `jerboa_bisect_crash` -> `jerboa_ffi_type_check`
+- **Learn a module**: `jerboa_stdlib_source` -> `jerboa_module_catalog` -> `jerboa_module_quickstart`
+- **Security audit**: `jerboa_security_audit` -> `jerboa_import_policy_check` -> `jerboa_unsafe_import_lint`
+- **Static build audit**: `jerboa_static_symbol_audit` -> `jerboa_boot_library_audit` -> `jerboa_rust_musl_build`
+- **Safe-by-default check**: `jerboa_safe_prelude_check` -> `jerboa_resource_leak_check` -> `jerboa_safe_prelude_generate`
+- **Debug editor command**: `jerboa_command_trace` with `project_path` and `buffer_type`
+
+## Workflow Conventions
+
+When implementing new features, always complete the documentation update in the same session. Document non-trivial solutions as howto recipes in the cookbook system.
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..1a12642
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Jaime Fournier
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..638396d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,10 @@
+.PHONY: verify run
+
+JERBOA_HOME ?= /Users/user/mine/jerboa
+JERBOA ?= $(JERBOA_HOME)/bin/jerboa
+
+verify:
+	JERBOA_HOME=$(JERBOA_HOME) $(JERBOA) run jerboa-slack.ss help
+
+run:
+	JERBOA_HOME=$(JERBOA_HOME) $(JERBOA) run jerboa-slack.ss tui
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..948eb92
--- /dev/null
+++ b/README.md
@@ -0,0 +1,42 @@
+# jerboa-slack
+
+Mux-friendly Slack chat client written in Jerboa.
+
+This repository also keeps a shallow checkout of Slack's official CLI at
+`vendor/slack-cli`. That upstream CLI is for Slack app development; this client
+uses Slack Web API methods for day-to-day chat.
+
+## Run
+
+```sh
+export SLACK_BOT_TOKEN='xoxb-...'
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss auth-test
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss channels
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss tui general
+```
+
+Useful commands:
+
+```sh
+make run
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss history general 20
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss send general "hello from jerboa"
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss replies general 1712345678.000100
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss reply general 1712345678.000100 "thread reply"
+JERBOA_HOME=/Users/user/mine/jerboa /Users/user/mine/jerboa/bin/jerboa run jerboa-slack.ss react general 1712345678.000100 thumbsup
+```
+
+The TUI is intentionally line-oriented instead of raw-mode curses. Inside the
+TUI, use `/help`, `/channels`, `/use <channel>`, `/history [limit]`, `/thread
+<ts>`, `/reply <ts> <text>`, `/react <ts> <emoji>`, `/send <text>`, and
+`/quit`. A normal non-empty line sends a message to the current channel.
+
+## Slack Scopes
+
+The token needs the Slack scopes that match what you want to do, commonly:
+
+- `channels:read`, `groups:read`, `im:read`, `mpim:read`
+- `channels:history`, `groups:history`, `im:history`, `mpim:history`
+- `chat:write`
+- `reactions:write`
+- `users:read` for display names instead of raw Slack user IDs
diff --git a/jerboa-slack.ss b/jerboa-slack.ss
new file mode 100644
index 0000000..0c11555
--- /dev/null
+++ b/jerboa-slack.ss
@@ -0,0 +1,418 @@
+#!/usr/bin/env jerboa run
+
+(import (jerboa prelude)
+        (std net request)
+        (std os env))
+
+(def api-root "https://slack.com/api/")
+(def default-channel-types "public_channel,private_channel,im,mpim")
+(def user-cache (make-hash-table))
+
+(def (usage)
+  (displayln "Usage: jerboa run jerboa-slack.ss <command> [args...]")
+  (displayln "")
+  (displayln "Commands:")
+  (displayln "  tui [channel]              Start mux-friendly chat UI")
+  (displayln "  channels                   List visible conversations")
+  (displayln "  history <channel> [limit]  Show recent messages")
+  (displayln "  send <channel> <text...>   Send a message")
+  (displayln "  reply <channel> <ts> <text...>")
+  (displayln "                              Reply in a thread")
+  (displayln "  replies <channel> <ts>     Show a thread")
+  (displayln "  react <channel> <ts> <emoji>")
+  (displayln "                              Add an emoji reaction")
+  (displayln "  auth-test                  Check token")
+  (displayln "")
+  (displayln "Environment:")
+  (displayln "  SLACK_BOT_TOKEN or SLACK_TOKEN must contain a Slack token."))
+
+(def (token)
+  (or (getenv "SLACK_BOT_TOKEN")
+      (getenv "SLACK_TOKEN")
+      (begin
+        (displayln "Missing SLACK_BOT_TOKEN or SLACK_TOKEN")
+        (exit 2))))
+
+(def (auth-headers)
+  `(("Authorization" . ,(string-append "Bearer " (token)))
+    ("Content-Type" . "application/json; charset=utf-8")))
+
+(def (api-url method params)
+  (let ([query (if (null? params) "" (string-append "?" (build-query-string params)))])
+    (string-append api-root method query)))
+
+(def (json-hash pairs)
+  (let ([h (make-hash-table)])
+    (for-each (lambda (p) (hash-put! h (car p) (cdr p))) pairs)
+    h))
+
+(def (jref obj key (default #f))
+  (if (and (hash-table? obj) (hash-key? obj key))
+      (hash-ref obj key)
+      default))
+
+(def (fail who msg . irritants)
+  (apply error who msg irritants))
+
+(def (json-response resp)
+  (let* ([body (request-text resp)]
+         [data (string->json-object body)])
+    (unless (= (request-status resp) 200)
+      (fail 'slack-api "HTTP error" (request-status resp) body))
+    (unless (jref data "ok" #f)
+      (fail 'slack-api "Slack API error" (jref data "error" "unknown_error")))
+    data))
+
+(def (slack-get method params)
+  (json-response (http-get (api-url method params) (auth-headers) #f)))
+
+(def (slack-post method payload)
+  (json-response
+    (http-post (api-url method '())
+               (auth-headers)
+               (json-object->string payload))))
+
+(def (slack-post-form method params)
+  (json-response
+    (http-post (api-url method '())
+               `(("Authorization" . ,(string-append "Bearer " (token)))
+                 ("Content-Type" . "application/x-www-form-urlencoded"))
+               (build-query-string params))))
+
+(def (vec->list v)
+  (if (vector? v) (vector->list v) '()))
+
+(def (safe-line s)
+  (let ([out (open-output-string)])
+    (string-for-each
+      (lambda (c)
+        (let ([n (char->integer c)])
+          (cond
+            [(or (= n 9) (= n 10) (>= n 32))
+             (unless (= n 27) (write-char c out))]
+            [else (void)])))
+      (if (string? s) s (str s)))
+    (get-output-string out)))
+
+(def (conversation-name c)
+  (or (jref c "name" #f)
+      (jref c "user" #f)
+      (jref c "id" "")))
+
+(def (conversation-id c) (jref c "id" ""))
+
+(def (conversation-label c)
+  (let ([name (conversation-name c)])
+    (if (string-prefix? "U" name) name (string-append "#" name))))
+
+(def (list-conversations)
+  (let loop ([cursor #f] [acc '()])
+    (let* ([params `(("limit" . "200")
+                     ("exclude_archived" . "true")
+                     ("types" . ,default-channel-types)
+                     ,@(if cursor `(("cursor" . ,cursor)) '()))]
+           [data (slack-get "conversations.list" params)]
+           [channels (vec->list (jref data "channels" '#()))]
+           [meta (jref data "response_metadata" #f)]
+           [next (and meta (jref meta "next_cursor" ""))])
+      (if (and next (not (string=? next "")))
+          (loop next (append acc channels))
+          (append acc channels)))))
+
+(def (find-conversation needle conversations)
+  (for/or ((c conversations))
+    (let ([id (conversation-id c)]
+          [name (conversation-name c)])
+      (and (or (string=? needle id)
+               (string=? needle name)
+               (string=? needle (string-append "#" name)))
+           c))))
+
+(def (resolve-channel needle)
+  (or (find-conversation needle (list-conversations))
+      (fail 'channel "conversation not found" needle)))
+
+(def (message-user msg)
+  (or (jref msg "user" #f)
+      (jref msg "username" #f)
+      (jref msg "bot_id" #f)
+      "unknown"))
+
+(def (user-display-name user)
+  (let ([profile (jref user "profile" #f)])
+    (or (and profile
+             (not (string-empty? (jref profile "display_name" "")))
+             (jref profile "display_name"))
+        (and profile
+             (not (string-empty? (jref profile "real_name" "")))
+             (jref profile "real_name"))
+        (jref user "name" #f)
+        (jref user "id" "unknown"))))
+
+(def (lookup-user-name uid)
+  (cond
+    [(not (string? uid)) "unknown"]
+    [(not (string-prefix? "U" uid)) uid]
+    [(hash-key? user-cache uid) (hash-ref user-cache uid)]
+    [else
+     (let ([name (unwrap-or
+                   (try-result*
+                     (let* ([data (slack-get "users.info" `(("user" . ,uid)))]
+                            [user (jref data "user" #f)])
+                       (if user (user-display-name user) uid)))
+                   uid)])
+       (hash-put! user-cache uid name)
+       name)]))
+
+(def (message-text msg)
+  (safe-line (jref msg "text" "")))
+
+(def (message-ts msg)
+  (jref msg "ts" ""))
+
+(def (message-thread-ts msg)
+  (jref msg "thread_ts" (message-ts msg)))
+
+(def (reaction-summary msg)
+  (let ([reactions (vec->list (jref msg "reactions" '#()))])
+    (if (null? reactions)
+        ""
+        (string-append
+          "  "
+          (string-join
+            (map (lambda (r)
+                   (format ":~a:~a"
+                           (jref r "name" "")
+                           (jref r "count" 0)))
+                 reactions)
+            " ")))))
+
+(def (thread-summary msg)
+  (let ([count (jref msg "reply_count" 0)])
+    (if (and (number? count) (> count 0))
+        (format "  replies:~a thread:~a" count (message-thread-ts msg))
+        "")))
+
+(def (fetch-history channel-id limit)
+  (let* ([data (slack-get "conversations.history"
+                          `(("channel" . ,channel-id)
+                            ("limit" . ,(number->string limit))))]
+         [messages (vec->list (jref data "messages" '#()))])
+    (reverse messages)))
+
+(def (fetch-replies channel-id ts)
+  (let* ([data (slack-get "conversations.replies"
+                          `(("channel" . ,channel-id)
+                            ("ts" . ,ts)))]
+         [messages (vec->list (jref data "messages" '#()))])
+    messages))
+
+(def (print-message msg)
+  (printf "[~a] ~a: ~a~a~a\n"
+          (message-ts msg)
+          (lookup-user-name (message-user msg))
+          (message-text msg)
+          (thread-summary msg)
+          (reaction-summary msg)))
+
+(def (cmd-channels)
+  (for-each
+    (lambda (c)
+      (printf "~a\t#~a\n" (conversation-id c) (conversation-name c)))
+    (list-conversations)))
+
+(def (cmd-history channel limit)
+  (let* ([c (resolve-channel channel)]
+         [cid (conversation-id c)])
+    (for-each print-message (fetch-history cid limit))))
+
+(def (cmd-send channel text)
+  (let* ([c (resolve-channel channel)]
+         [cid (conversation-id c)]
+         [payload (json-hash `(("channel" . ,cid) ("text" . ,text)))]
+         [data (slack-post "chat.postMessage" payload)])
+    (printf "sent ~a to #~a\n" (jref data "ts" "") (conversation-name c))))
+
+(def (cmd-reply channel ts text)
+  (let* ([c (resolve-channel channel)]
+         [cid (conversation-id c)]
+         [payload (json-hash `(("channel" . ,cid)
+                               ("thread_ts" . ,ts)
+                               ("text" . ,text)))]
+         [data (slack-post "chat.postMessage" payload)])
+    (printf "replied ~a in #~a thread ~a\n"
+            (jref data "ts" "")
+            (conversation-name c)
+            ts)))
+
+(def (cmd-replies channel ts)
+  (let* ([c (resolve-channel channel)]
+         [cid (conversation-id c)])
+    (for-each print-message (fetch-replies cid ts))))
+
+(def (cmd-react channel ts emoji)
+  (let* ([c (resolve-channel channel)]
+         [cid (conversation-id c)]
+         [name (if (and (> (string-length emoji) 1)
+                        (string-prefix? ":" emoji)
+                        (string-suffix? ":" emoji))
+                   (substring emoji 1 (- (string-length emoji) 1))
+                   emoji)])
+    (slack-post-form "reactions.add"
+                     `(("channel" . ,cid)
+                       ("timestamp" . ,ts)
+                       ("name" . ,name)))
+    (printf "reacted :~a: to ~a in #~a\n" name ts (conversation-name c))))
+
+(def (cmd-auth-test)
+  (let ([data (slack-get "auth.test" '())])
+    (printf "ok: team=~a user=~a\n"
+            (jref data "team" "")
+            (jref data "user" ""))))
+
+(def (clear-screen)
+  (display "\x1b;[2J\x1b;[H"))
+
+(def (render-tui current limit)
+  (clear-screen)
+  (printf "jerboa-slack  channel: #~a  (/help for commands)\n"
+          (conversation-name current))
+  (displayln "------------------------------------------------------------")
+  (for-each print-message (fetch-history (conversation-id current) limit))
+  (displayln "------------------------------------------------------------"))
+
+(def (tui-help)
+  (displayln "/channels              list conversations")
+  (displayln "/use <channel>         switch channel by id or name")
+  (displayln "/history [limit]       redraw recent messages")
+  (displayln "/thread <ts>           show replies for a message")
+  (displayln "/reply <ts> <text>     reply in a thread")
+  (displayln "/react <ts> <emoji>    add an emoji reaction")
+  (displayln "/send <text>           send text to current channel")
+  (displayln "/help                  show commands")
+  (displayln "/quit                  exit")
+  (displayln "Any non-empty line that is not a command is sent as a message."))
+
+(def (split-command line)
+  (let ([parts (string-split line #\space)])
+    (filter (lambda (x) (not (string-empty? x))) parts)))
+
+(def (drop-command-prefix line cmd)
+  (let ([n (string-length cmd)])
+    (string-trim
+      (if (> (string-length line) n)
+          (substring line n (string-length line))
+          ""))))
+
+(def (run-tui initial)
+  (let* ([channels (list-conversations)]
+         [current (if initial
+                      (or (find-conversation initial channels)
+                          (fail 'channel "conversation not found" initial))
+                      (if (null? channels)
+                          (fail 'slack "no conversations returned")
+                          (car channels)))]
+         [limit 30])
+    (render-tui current limit)
+    (let loop ([current current] [limit limit])
+      (display "> ")
+      (flush-output-port (current-output-port))
+      (let ([line (get-line (current-input-port))])
+        (cond
+          [(eof-object? line) (displayln "")]
+          [(string-empty? (string-trim line)) (loop current limit)]
+          [(string=? line "/quit") (displayln "bye")]
+          [(string=? line "/help")
+           (tui-help)
+           (loop current limit)]
+          [(string=? line "/channels")
+           (cmd-channels)
+           (loop current limit)]
+          [(string-prefix? "/use " line)
+           (let ([next (resolve-channel (drop-command-prefix line "/use"))])
+             (render-tui next limit)
+             (loop next limit))]
+          [(string-prefix? "/history" line)
+           (let* ([arg (drop-command-prefix line "/history")]
+                  [n (if (string-empty? arg) limit (or (string->number arg) limit))])
+             (render-tui current n)
+             (loop current n))]
+          [(string-prefix? "/thread " line)
+           (cmd-replies (conversation-id current) (drop-command-prefix line "/thread"))
+           (loop current limit)]
+          [(string-prefix? "/reply " line)
+           (let* ([rest (drop-command-prefix line "/reply")]
+                  [parts (split-command rest)])
+             (if (< (length parts) 2)
+                 (displayln "usage: /reply <ts> <text>")
+                 (cmd-reply (conversation-id current)
+                            (car parts)
+                            (drop-command-prefix rest (car parts)))))
+           (loop current limit)]
+          [(string-prefix? "/react " line)
+           (let ([parts (split-command (drop-command-prefix line "/react"))])
+             (if (< (length parts) 2)
+                 (displayln "usage: /react <ts> <emoji>")
+                 (cmd-react (conversation-id current) (car parts) (cadr parts))))
+           (loop current limit)]
+          [(string-prefix? "/send " line)
+           (cmd-send (conversation-id current) (drop-command-prefix line "/send"))
+           (render-tui current limit)
+           (loop current limit)]
+          [(string-prefix? "/" line)
+           (displayln "unknown command")
+           (loop current limit)]
+          [else
+           (cmd-send (conversation-id current) line)
+           (render-tui current limit)
+           (loop current limit)])))))
+
+(def (join-words xs)
+  (string-join xs " "))
+
+(def (main argv)
+  (let ([args (cdr argv)])
+    (cond
+      [(null? args) (usage)]
+      [(string=? (car args) "channels") (cmd-channels)]
+      [(string=? (car args) "auth-test") (cmd-auth-test)]
+      [(string=? (car args) "history")
+       (unless (>= (length args) 2)
+         (usage)
+         (exit 2))
+       (cmd-history (cadr args)
+                    (if (>= (length args) 3)
+                        (or (string->number (caddr args)) 30)
+                        30))]
+      [(string=? (car args) "send")
+       (unless (>= (length args) 3)
+         (usage)
+         (exit 2))
+       (cmd-send (cadr args) (join-words (cddr args)))]
+      [(string=? (car args) "reply")
+       (unless (>= (length args) 4)
+         (usage)
+         (exit 2))