Opencancer MCP server

Which servers in the official MCP registry are Opencancer's own, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-18

← Back to Opencancer

Whose server it is

Registry nameai.opencancer/opencancerverified in the MCP registry

The registry name sits under opencancer.ai. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-18

Stateanswerschecked 2026-10-18
Tools5
Server calls itselfopencancer
Server version2.0.0
Protocol version2025-06-18

On 2026-10-18 the server answered initialize and tools/list without a sign-in. First answer in 121 ms.

Measured dailydaily checks: 1, the first on 2026-10-19

Answeredmeasuring1 of the 7 daily checks it takes to print a share
Median first answer190 ms
Space in an agent's context≈ 1,287 tokensthe definitions of all its tools (5), which an agent carries on every turn
Tool definitionsA · 97 of 100

Parameters without a description: in 1 of 5

Worth a look

Tools that delete, send or pay without telling the client so: send_feedback
Tools that change data, on a server that answers without a sign-in: send_feedback

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The state of vendors' MCP servers: method and numbers →

Tools it offers5 tools · read 2026-10-18

ask_opencancer
Answers a cancer patient or caregiver question in plain language, grounded in NCCN Guidelines for Patients and medical literature. Covers what a diagnosis, stage, biomarker or test result means; treatment options; side effects and their…
find_clinical_trials
Lists clinical trials recruiting now for a cancer type, from ClinicalTrials.gov, optionally near a city, state or country and filtered by a biomarker, drug or treatment keyword and by phase. Returns up to 8 trials with NCT number, phase…
get_trial_details
Returns one clinical trial from ClinicalTrials.gov by its NCT number: what it tests, phase, status, last registry update, ages, the inclusion and exclusion criteria in their original wording, recruiting sites with their status, study…
open_case
Returns a link where a patient can start an expert review of their case by OpenCancer and Cancer Commons scientists (records, options, trial shortlist, next step). The link only opens an intake page: no case is created and no records are…
send_feedback
Flags an OpenCancer answer for human expert review, or sends feedback to the OpenCancer team. Used when the user says an OpenCancer answer was wrong, unsafe, or incomplete, or wants to tell OpenCancer something (answer_id identifies the…

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "opencancer": {
      "type": "http",
      "url": "https://opencancer.ai/api/mcp"
    }
  }
}

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.