What is ken CLAUDE.md?

Repository instructions for ken, a Go code-search tool that combines text matching with meaning-based search and combines their results. They explain the project, its design documents, and who is allowed to edit it.

Finding the right project documentation before coding, maintaining ken’s search behavior, and following its editing and design-review process.

They provide the background and ownership rules needed to change the search tool safely and consistently.

How townsendmerino/ken configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to townsendmerino/ken. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/townsendmerino/ken/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/townsendmerino/ken

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/townsendmerino/ken/claude-md/github.svg)](https://agentmods.dev/instructions/townsendmerino/ken/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/townsendmerino/ken/claude-md"><img src="https://agentmods.dev/badge/instructions/townsendmerino/ken/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/townsendmerino/ken/claude-md"><img src="https://agentmods.dev/badge/instructions/townsendmerino/ken/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,030 This file is loaded in full into every session.

When invoked 1,030 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.01030	$0.01030
Opus 5.5	$0.00412	$0.00412
Sonnet 5.5	$0.00206	$0.00206
Haiku 4.5	$0.00103	$0.00103

Measured 6d ago against content hash b7082bac73a7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ken CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 53 lines

How it starts

The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

ken is a pure-Go, no-cgo port of MinishLab/semble: hybrid code search (BM25 + Model2Vec embeddings, RRF fusion, rerank heuristics), a CLI (cmd/ken), an MCP server (cmd/ken-mcp) and a library (engine). Read docs/DESIGN.md (algorithm spec, precision contracts, risk register) before any non-trivial change; ARCHITECTURE.md maps the packages, docs/internal/DECISIONS.md holds the ADRs, docs/BENCH.md the benchmarks, and the README the install snippets and env vars.

Ownership

Claude Code is the sole editor of this repository. The Claude app is for design discussion only and does not modify files here. The algorithm packages (chunk, bm25, embed, ann, encoder, topk, fuse) live in the sibling aikit repo (ADR-034): edit them there. Keep the tree gofmt-clean and go test ./... green on every change.

Commands

go build ./... && go vet ./...                     # vet must be clean
go test ./...                                      # all tests; semantic/hybrid tests skip without testdata/model
go test ./internal/search/ -run TestSerializeRoundtrip_BM25 -v
make gofmt-check                                   # CI's gofmt gate (scope: Makefile GOFMT_DIRS)
GOWORK=off make check                              # pre-push: gofmt, the pinned golangci-lint, vet, tests, as CI runs them
go run ./cmd/ken index <path>                      # watches by default; --no-watch builds once
go run ./cmd/ken search <path> <query>... [-k N] [--mode=bm25|semantic|hybrid]
go run ./cmd/ken doctor

Hybrid and semantic modes find the model at --model, then $KEN_MODEL_DIR, ~/.ken/model (ken download-model fills it) and ./testdata/model (not committed; testdata/README.md).

go.mod's go directive is the single toolchain pin. After a go or aikit bump run go mod tidy, and for aikit re-run the parity and recall checks (aikit's TestGolden_EmbeddingCosine against a real model). A golangci-lint older than the toolchain cannot read its export data and checks nothing: use the Makefile's pinned version.

Read the full file on GitHub · 53 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

6d ago Changed · -77 lines · -7,382 tokens per session scan B → A b7082bac73a7
7d ago Changed · +167 tokens per session ec1f4b925168
15d ago Changed · +1 lines · +290 tokens per session 157168b56015
16d ago Changed · +61 tokens per session 69ada08561c7
21d ago Changed · +1 lines · +457 tokens per session 2e3c5d2bb023
1mo ago Changed · +1 lines · +243 tokens per session 68f14d5ffacb
2mo ago Changed · +561 tokens per session dcd03c817646
2mo ago First seen · 127 lines · 6,633 tokens per session scan B 582a377f42a0

Subscribe to this mod's changes

ken CLAUDE.md is an instructions file published in the GitHub repository townsendmerino/ken (33 stars, last pushed yesterday), licensed MIT. It adds 1,030 tokens to every session, about $0.0041 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Data and AI Go agents bm25 code-search embeddings go

ken CLAUDE.md next to 6 instructions from other repositories
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ken: Instructions file for Claude Code