MCP Composer is a FastMCP server that combines tools from multiple Model Context Protocol servers behind one endpoint. It is for exposing member servers that use HTTP, SSE, stdio, OpenAPI, or GraphQL through a single configured tool surface. The catalogue instruction supports working with this composer.
Borrowing it
Nothing to install: this file belongs to IBM/mcp-composer. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/IBM/mcp-composer/main/AGENTS.mdgit clone --depth 1 https://github.com/IBM/mcp-composerWrote 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.
[](https://agentmods.dev/instructions/ibm/mcp-composer/agents-md)<a href="https://agentmods.dev/instructions/ibm/mcp-composer/agents-md"><img src="https://agentmods.dev/badge/instructions/ibm/mcp-composer/agents-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.
<a href="https://agentmods.dev/instructions/ibm/mcp-composer/agents-md"><img src="https://agentmods.dev/badge/instructions/ibm/mcp-composer/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00249 | $0.00249 |
| Opus 5.5 | $0.00100 | $0.00100 |
| Sonnet 5.5 | $0.00050 | $0.00050 |
| Haiku 4.5 | $0.00025 | $0.00025 |
Grade A, and why
mcp-composer 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 21d 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.
What it actually says
Agent notes
Read CONTRIBUTING.md before changing this repository. The same rules apply to human and agent authors: a short problem statement, a reproduction, a scoped diff, and tests.
Layout
- Package:
modules/mcp_composer(src/mcp_composer) - Unit tests:
modules/mcp_composer/tests/unit - Docs:
docs/ - Root
Makefiletargets expectmodule=mcp_composer
Required checks
From modules/mcp_composer:
uv sync --group dev
uv run pytest tests/unit -q
uv run ruff check .
uv run black --check .
Do not treat a green test run as permission to change an intentional security contract. Stdio member servers require MCP_COMPOSER_STDIO_ALLOWLIST. Non-loopback HTTP binds require authentication.
Out of scope for drive-by edits
- Internal deployment hostnames, registries, and private GitHub links do not belong in public docs.
- Do not reintroduce removed product-specific adapters or examples.
- Do not weaken auth, allowlist, or default-bind checks to make a test pass.
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.
- 21d ago First seen · 30 lines · 249 tokens per session scan A d3e9a3366312
mcp-composer AGENTS.md is an instructions file published in the GitHub repository IBM/mcp-composer (22 stars, last pushed today), licensed Apache-2.0. It adds 249 tokens to every session, about $0.0010 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 2026-10-09.
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