MCP guides
MCP server guides
Everything we have written on running an MCP server in production: how to secure it, how sign-in works, how to design its tools and how to test them with real agents.
Written by Octri · Checked 3 November 2026
MCP security
What the specification requires of a server, what teams add for production, and how Octri handles each topic.
- MCP security best practicesThe full checklist: sign-in, token checks, least privilege, approvals, limits and audit logs.
- MCP OAuth and authorizationThe sign-in flow in request order, from the first 401 to a scoped access token.
- Token passthrough and confused deputyWhat the specification forbids, why it does, and how per-client consent closes the proxy attack.
- Tool poisoning and prompt injectionHow instructions reach a model through tool metadata and results, and the controls that contain them.
- MCP audit logs and rate limitsThe fields worth recording for each tool call, and how to size per-tool limits and write caps.
Articles by topic
Permissions and hostile content
What an agent can reach once it is connected, and what to do about the text it reads back.
- Your read-only MCP server can still carry a prompt injectionTreating customer-controlled API content as untrusted data through a whole agent workflow.
- Your MCP server authenticates users. Does it preserve their permissions?Following identity from the MCP client to the downstream API, across audiences and tenants.
- Giving an agent write access to your API: what to exclude firstChoosing the endpoints an agent should never reach before you connect one.
MCP tool design
How many tools to expose, how much each one returns, and what an integrator needs written down.
- How many tools should an MCP server expose?Tool choice as a selection problem, and what each extra option costs.
- Your API response is eating the agent’s context windowFiltering, selecting and aggregating before a large payload enters the context window.
- One user, 200 API calls: rate limits when agents run in parallelCoordinating agent fan-out against shared request and concurrency budgets.
- Your MCP server needs documentation, and it is not your API docsWhat belongs in the README and config snippet an integrator receives.
MCP beside other interfaces
Where MCP sits next to the OpenAPI document and the command line.
Testing with agents
Measuring whether an agent can do the job with what you published.
Questions
Yes. The requirements come from the MCP specification and apply to any server. Each security guide ends with a short section on how Octri handles the topic, and the rest stands on its own.
Try it on your own spec
Generate an MCP server from your OpenAPI spec on the Free plan, with every tool set to run, ask first or stay off.