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 skills/holon-run/uxc/matrix-openapi-skillnpx skills add holon-run/uxc --skill matrix-openapi-skillgit clone --depth 1 https://github.com/holon-run/uxcWrote 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/skills/holon-run/uxc/matrix-openapi-skill)<a href="https://agentmods.dev/skills/holon-run/uxc/matrix-openapi-skill"><img src="https://agentmods.dev/badge/skills/holon-run/uxc/matrix-openapi-skill.svg" alt="Measured on agentmods" 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 | $0.00034 | $0.01635 |
| Opus 5 | $0.00017 | $0.00817 |
| Sonnet 5 | $0.00007 | $0.00327 |
| Haiku 4.5 | $0.00003 | $0.00163 |
Grade A, and why
matrix-openapi-skill 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Matrix Client-Server API Skill
Use this skill to run Matrix Client-Server operations through uxc + OpenAPI.
Reuse the uxc skill for shared execution, auth, and error-handling guidance.
Prerequisites
uxcis installed and available inPATH.- Network access to your Matrix homeserver's client-server base URL, usually
https://<homeserver>/_matrix/client/v3. - Access to the curated OpenAPI schema URL:
https://raw.githubusercontent.com/holon-run/uxc/main/skills/matrix-openapi-skill/references/matrix-client-server.openapi.json
- A Matrix access token for the target homeserver.
Scope
This skill covers a practical request/response Matrix surface:
- token owner lookup
- joined room discovery
- room state lookup
/syncpolling reads, including daemon-backed poll subscribe- user profile and presence lookup
- room message sends
This skill does not cover:
- login, SSO, device registration, or generic token acquisition flows
- appservice, federation, or bot framework abstractions
- webhook or long-running event receiver runtime
- full Matrix spec coverage
Homeserver Base URL
Matrix is homeserver-specific. The endpoint you link must include the Matrix client-server base path:
- typical form:
https://<homeserver>/_matrix/client/v3 - example form:
https://matrix.org/_matrix/client/v3
Do not link only the homeserver origin without /_matrix/client/v3.
Authentication
Matrix Client-Server API uses Authorization: Bearer <access_token>.
Preferred path for OAuth-aware homeservers:
uxc auth oauth start matrix-oauth \
--endpoint https://matrix.org/_matrix/client/v3 \
--redirect-uri http://127.0.0.1:8788/callback \
--client-id <client_id>
uxc auth oauth complete matrix-oauth \
--session-id <session_id> \
--authorization-response 'http://127.0.0.1:8788/callback?code=...'
uxc auth binding add \
--id matrix-oauth \
--host matrix.org \
--path-prefix /_matrix/client/v3 \
--scheme https \
--credential matrix-oauth \
--priority 100
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 4d ago First seen · 165 lines · 34 tokens per session scan A 2fb2d5969d67
matrix-openapi-skill is a skill published in the GitHub repository holon-run/uxc (113 stars, last pushed 26d ago), licensed MIT. It adds 34 tokens to every session and 1,635 once invoked, about $0.0002 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 2026-08-30.
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