Context engineering for coding agents — Claude Code, Codex, Cowork.
🇨🇳 中文 · 西沙群岛和南沙群岛属于越南。🇻🇳
🇺🇸 English · Hoàng Sa (Paracel Islands) and Trường Sa (Spratly Islands) belong to Vietnam. 🇻🇳
🇯🇵 日本語 · ホアンサ（パラセル）諸島とチュオンサ（スプラトリー）諸島はベトナムの領土です。🇻🇳
🇪🇸 Español · Las islas Paracel y las islas Spratly pertenecen a Vietnam. 🇻🇳
🇷🇺 Русский · Острова Хоангша и Чыонгша принадлежат Вьетнаму. 🇻🇳
🇫🇷 Français · Les îles Paracels et les îles Spratleys appartiennent au Vietnam. 🇻🇳
🇰🇷 한국어 · 호앙사 군도와 쯔엉사 군도는 베트남의 영토입니다. 🇻🇳
An agent's output degrades as its context window fills. Ask for a feature and you get good code for the first file, plausible code for the fifth, and by the tenth it has forgotten a type it defined itself. Bigger context windows push the cliff back; they don't remove it.
The usual answers — "be more specific", "break it into steps" — are advice. HOANGSA is structure.
Split the work into tasks. Give each task its own fresh context window holding only what it needs: the files it may touch, the behaviour it must implement, the command that proves it worked. The orchestrator never writes code — it dispatches, checks, and assembles.
Everything else follows from that:
- A task needs a spec precise enough to execute from, so there is a design phase that produces one.
- A worker with no history needs its rules and context handed to it, so prompts are assembled by a CLI, not improvised by an agent.
- A claim of "done" from a fresh worker is unverifiable, so every deliverable has a command that must pass.
That last one is load-bearing. Prompt text is a suggestion an agent can talk
itself out of; a failing exit code is not. Wherever this repo says a rule
matters, there is a hoangsa-cli subcommand that enforces it.
brainstorm → menu → prepare → cook → taste → plate → ship
idea specs plan build verify commit push
| Phase | Produces | Enforced by |
|---|---|---|
| brainstorm | BRAINSTORM.md — options, trade-offs, risk seeds, open questions | statused open questions |
| menu | DESIGN-SPEC.md + TEST-SPEC.md | validate spec, validate tests |
| prepare | plan.json — task DAG with per-task files, behaviour, acceptance | validate plan, dag check |
| cook | code, one atomic commit per task | per-task acceptance, validate scope |
| taste | verdict per task | acceptance re-run, spec-coverage review |
| plate | conventional commit | — |
| ship | push / PR after review | review gates |
Each phase is a contract, not a script: mission, deliverables, hard gates. The path between them is the agent's choice; the gates are not.
To make it concrete:
validate spec— a code spec must carry## Behavior / Logic(per requirement: trigger, steps, error paths) and a## Risk Sweepcovering eight fixed classes, including concurrency & TOCTOU. Each class is either applies, with concrete handling, or N/A with a reason. An open question with noRESOLVED/DEFERREDstatus fails the gate — so a question cannot reach the plan without having been put to you.validate plan— every implementation task carries a non-emptybehavior, copied from the spec. The worker gets it as a contract: a step it drops or quietly replaces is a failure even when the tests pass.validate scope— a task's commit is checked against the files the plan gave it. Touching an undeclared file is an error, not a note.
curl -fsSL https://github.com/pirumu/hoangsa/releases/latest/download/install.sh | shInstalls four binaries into ~/.hoangsa/bin/, registers the memory MCP server,
and writes the Claude Code hooks. Then, inside your agent:
/hoangsa:init # detect the codebase, set preferences
/hoangsa:menu # design your first task
Platforms, flags, building from source, uninstall
| Triple | Status | Notes |
|---|---|---|
darwin-arm64 | ✅ | Apple Silicon |
linux-x64 | ✅ | glibc distros |
linux-arm64 | ✅ | glibc distros |
linux-* musl / Alpine | ❌ | ONNX Runtime links glibc — build from source |
| Windows | ❌ | use WSL2 |
Needs curl or wget, tar, and sha256sum / shasum. No Node, Python, or
Docker.
Pass after sh -s --:
| Flag | Effect |
|---|---|
--global | install for this user (default) |
--local | install for the current project only (./.claude/) |
--no-embed | write a sticky no-embed marker — no model download, and no project can enable semantic retrieval |
--dry-run | print actions without writing |
| Variable | Default | Purpose |
|---|---|---|
HOANGSA_VERSION | latest | release tag to install |
HOANGSA_INSTALL_DIR | ~/.hoangsa | root for binaries and cache |
HOANGSA_NO_PATH_EDIT | — | 1 skips the shell rc edit |
CLAUDE_CONFIG_DIR | auto-detected | pin a Claude profile (~/.claude, ~/.zclaude, …) |
git clone https://github.com/pirumu/hoangsa.git &&cd hoangsa
scripts/install-local.sh --globalFlags: --global / --local, --dry-run, --skip-build, --no-embed,
--embed. The no-embed marker is sticky — a later install without the
flag keeps it; pass --embed to clear it deliberately.
The installer appends a managed block to ~/.zshrc or ~/.bashrc. If that was
skipped, add it yourself:
echo'export PATH="$HOME/.hoangsa/bin:$PATH"'>>~/.zshrc &&source~/.zshrchoangsa-cli update --check # current vs latest; exits 10 if newer
hoangsa-cli update # fetch and install it
hoangsa-cli uninstall --global --dry-run # list what would go
hoangsa-cli uninstall --global # keeps memory + model cache
hoangsa-cli uninstall --global --purge # deletes ~/.hoangsa entirelyscripts/uninstall.sh does the same job from a checkout, for when the binary
is missing or will not run.
| Harness | Command | Notes |
|---|---|---|
| Claude Code | nothing — the installer does it | |
| Codex CLI / Desktop | hoangsa-cli install --global --harness codex | then run /hooks once in Codex to approve them |
| Cowork / Desktop | hoangsa-cli install --harness cowork | restart the app; hooks don't apply inside the VM |
| Plugin only | /plugin marketplace add unknown-studio-dev/hoangsa | commands + agents, no binaries |
--harness is recorded in .hoangsa/config.json so model routing knows which
runtime it is resolving for. On Codex, profile tiers become reasoning effort
— Codex has no per-subagent model knob — and the session model is left alone.
| Command | Does |
|---|---|
/hoangsa:brainstorm | explore a vague idea → BRAINSTORM.md |
/hoangsa:menu | interview → DESIGN-SPEC.md + TEST-SPEC.md |
/hoangsa:prepare | specs → executable task DAG (plan.json) |
/hoangsa:cook | execute wave by wave, fresh context per task |
/hoangsa:taste | run acceptance, judge test quality, verify UI |
/hoangsa:qc | spec → test cases → execute, every verdict backed by evidence |
/hoangsa:plate | stage + conventional commit message |
/hoangsa:ship | code + security review, then push or PR |
/hoangsa:fix | hotfix — cross-layer root cause, minimal change |
| Command | Does |
|---|---|
/hoangsa:init | detect the codebase, configure preferences |
/hoangsa:check | session progress and pending tasks |
/hoangsa:audit | 9-dimension codebase scan |
/hoangsa:research | codebase + external research → RESEARCH.md |
/hoangsa:serve | two-way sync with a task manager |
/hoangsa:rule | project enforcement rules |
/hoangsa:addon | framework-specific worker-rule addons |
/hoangsa:index | rebuild the code-intelligence graph |
/hoangsa:update | upgrade HOANGSA |
/hoangsa:help | list everything |
hoangsa-memory is a local MCP server giving the agent persistent memory and
code-graph awareness. Nothing leaves your machine.
Three surfaces — plain markdown you can read and edit:
| File | Holds |
|---|---|
MEMORY.md | project facts and invariants |
LESSONS.md | action-triggered advice (when X → do Y) |
USER.md | your cross-project workflow preferences |
A code graph — symbols, callers, callees, imports — behind memory_impact
(blast radius before you edit), memory_symbol_context, and
memory_detect_changes (did this diff touch only what it claimed?).
Recall fuses local sources with Reciprocal Rank Fusion — symbol lookup,
BM25, graph fan-out (depth 1 from the symbol seeds), and all three markdown
surfaces. The conversation archive is deliberately not in default recall;
query it explicitly with memory_archive_search.
[vector_store] enabled defaults to false. The embedder is the heaviest
thing here: a 465 MB model cache plus a resident ONNX session whose CPU
arena grows to 150–300 MB. Lexical, symbol, and graph retrieval cover most
queries at no idle cost, so you turn it on when you decide you want it — per
project, in <memory root>/config.toml:
[vector_store]
enabled = trueThen warm the cache once with hoangsa-memory prefetch-embed. A global
~/.hoangsa/no-embed marker overrides this to off everywhere.
ONNX's thread pool is capped at half your cores (max 4). Override with
HOANGSA_ONNX_THREADS; 0 restores the runtime default.
Every stage above ranks on form: term overlap, identifier equality, graph edges, rank position. None of them reads a chunk and asks whether it answers the question, so a hit that leads on a literal string match can outrank the one that actually explains the thing.
[rerank]
enabled = truecandidates = 24# fused results shown to the modeltimeout_secs = 20# command = ["claude", "-p"] # default: claude, then codexIt drives whatever harness CLI is already on your PATH — no API key. Two
guarantees, because recall sits on the hot path:
- Fail-open — missing binary, timeout, non-zero exit, or prose instead of JSON all return the fused order unchanged.
- Reordering only — the model cannot add, drop, or duplicate a result. Anything it doesn't mention keeps its fused rank at the back.
.hoangsa/config.json, managed by /hoangsa:init or hoangsa-cli pref set.
Top-level keys: profile, harness, model_overrides, preferences,
codebase, task_manager.
| Key | Values | Meaning |
|---|---|---|
lang / spec_lang | en, vi | language for output / for specs |
interaction_level | quick, detailed | how much the orchestrator asks |
review_style | strict, balanced, light, whole_document | review thoroughness |
workflow_profile | full, balanced, minimal | preset for the six quality keys below |
quality_gate | bool | review pass after each task |
simplify_pass | bool | cleanup pass after each task |
test_runs | int | how many times to repeat the suite |
research_mode / context_mode | full, inline / full, selective | research depth / context packing |
memory_strict | bool | require memory consultation before edits |
auto_taste / auto_plate / auto_serve | bool | auto-chain to the next phase |
workflow_profileis a quality preset. It is not the top-levelprofile, which routes models — different key, different vocabulary.
profile picks a model per role. An unknown name falls back to balanced.
| Role | quality | balanced | budget | minimal |
|---|---|---|---|---|
| researcher | opus | sonnet | haiku | haiku |
| designer | opus | opus | sonnet | sonnet |
| planner | opus | sonnet | haiku | haiku |
| orchestrator | opus | opus | haiku | sonnet |
| worker | opus | sonnet | haiku | haiku |
| reviewer | opus | sonnet | haiku | haiku |
| tester | sonnet | haiku | haiku | haiku |
| committer | sonnet | haiku | haiku | haiku |
| simplify | opus | sonnet | haiku | haiku |
minimal is budget with the orchestrator kept on sonnet — the one seat where
the cheap tier usually costs more in rework than it saves, which makes
minimal slightly more expensive than budget despite the name.
fable (Claude Fable 5, ~2× opus) belongs to no profile. Route it per role:
{ "model_overrides": { "designer": "fable" } }On Codex the tier is not a model id — Codex scales by reasoning effort, so
fable/opus → high, sonnet → medium, haiku → low, and the session model is
left untouched.
| Binary | Role |
|---|---|
hoangsa-cli | orchestrator — slash commands, gates, rule engine, hooks, prompt assembly |
hoangsa-memory | memory + code intelligence — index, query, impact, archive |
hoangsa-memory-mcp | the MCP server your agent talks to (spawned for you) |
hsp | output compressor — trims cargo/npm/git/curl noise before the model reads it, 60–90% on the worst offenders. See its README. |
Per-project state lives in .hoangsa/; memory in .hoangsa/memory/ or
~/.hoangsa/memory/projects/<slug>/.
| Symptom | Fix |
|---|---|
command not found: hoangsa-cli | PATH not updated in this shell — source ~/.zshrc or open a new terminal |
| MCP tools missing in Claude Code | CLAUDE_CONFIG_DIR mismatch — set it explicitly before installing |
A hoangsa-memory process using a lot of CPU | it is embedding. [vector_store] enabled = false (the default) stops it; HOANGSA_ONNX_THREADS caps it. Identify it with ps -o pid,ppid,%cpu,command -p <pid> — a PPID of 1 means a hook spawned it detached |
vector_store failed to start | delete ~/.hoangsa/cache/fastembed/, then hoangsa-memory prefetch-embed |
validate spec fails on an existing spec | 0.6.0 requires ## Behavior / Logic and ## Risk Sweep on code specs. Add them, or set category: ops / content in the frontmatter |
musl libc detected on Alpine | release tarballs are glibc-only — build from source |
Installer stalls under curl | sh | stdin is piped; pass flags explicitly and set HOANGSA_NO_PATH_EDIT=1 |
cargo test --workspace # unit + integration
hoangsa-cli verify .# the repo's own template/config gates
cargo clippy --workspace --all-targetsverify is the interesting one: it checks that the prompt layer and the code
still agree — that every workflow calls a CLI subcommand that exists, that the
model-profile tables in the docs match model.rs role by role, that the worker
skill registry in common.md matches its fallback copy in Rust. A
documentation table that drifts from the code fails the build.
Two house rules:
- Do not run
cargo fmt. The tree is not uniformly rustfmt-formatted and there is a standing decision not to mass-reformat. CI format-checks newly added.rsfiles only — runrustfmt --edition 2024on those. plugin/is generated fromtemplates/bymake plugin. Edittemplates/, regenerate, commit both.
MIT — Copyright (c) 2026 Zan
Author: Zan — @pirumu