Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/elsheppo/chumbo/agents-mdgit clone --depth 1 https://github.com/elsheppo/chumboWhat 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 | $0.01511 | $0.01511 |
| Opus 5 | $0.00756 | $0.00756 |
| Sonnet 5 | $0.00302 | $0.00302 |
| Haiku 4.5 | $0.00151 | $0.00151 |
Grade A, and why
chumbo AGENTS.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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 143 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Chumbo agent guide
What this repository is
Chumbo turns an existing Supabase application into an end-user-facing MCP server. The package provides a TypeScript runtime, a guided CLI, and generated Supabase Edge Function templates.
The happy path is deliberately small: a builder runs npx chumbo setup,
implements application capabilities in the generated capabilities.ts,
deploys one Edge Function, and lets existing Supabase or application auth
govern access.
Keep the value clear
Chumbo makes one Supabase-native MCP easy and supports increasingly advanced patterns – including many MCPs from one function – through the same library. The default path stays small: one builder's app exposes builder-authored capabilities to that app's users. Advanced patterns must remain optional and must not burden that setup.
The package owns the reusable boundary between an existing Supabase app and MCP: protocol/runtime wiring, request-scoped identity, simple auth modes, guided setup, diagnostics, and result helpers. The repository also owns a living Supabase reference project whose tested patterns show how to compose that same API with Supabase-native capabilities.
Do not impose application architecture merely because an advanced pattern can use it. In particular, Chumbo does not prescribe:
- downstream API proxying, credential storage, or credential brokerage;
- database introspection that guesses and generates an application's tools;
- application schemas, organization models, or entitlement conventions;
- domain-specific tool behavior or purpose-written renderers.
Row-defined servers, path-based resolution, queued work, Storage resources,
Cron, Realtime, and search are valid Chumbo patterns when they use the same
public library and come with executable evidence. Keep application intelligence
in generated capabilities.ts or pattern code. Promote an abstraction into the
package API only when it simplifies real adopters without imposing a new
architecture on the ordinary one-MCP path.
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.
- yesterday First seen · 143 lines · 1,511 tokens per session scan A d21265a626d9
chumbo AGENTS.md is an instructions file published in the GitHub repository elsheppo/chumbo (1 stars, last pushed 2d ago), licensed MIT. It adds 1,511 tokens to every session, about $0.0076 per session on Opus 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 2026-08-31.
Other instructions, from other repositories
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next.js AGENTS.md
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vscode oss-third-party-notices.instructions.md
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spec-kit AGENTS.md
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langchain AGENTS.md
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