CircleCI MCP Server

Instructions

Implementation Reference

• src/tools/createPromptTemplate/handler.ts:12-46 (handler)

  Core handler function that invokes CircletClient to create a structured prompt template from input prompt and origin, then returns formatted text output with extracted keys (promptOrigin, template, contextSchema, model) and instructions for next tool call.

  export const createPromptTemplate: ToolCallback<{
    params: typeof createPromptTemplateInputSchema;
  }> = async (args) => {
    const { prompt, promptOrigin, model } = args.params;
  
    const circlet = new CircletClient();
    const promptObject = await circlet.circlet.createPromptTemplate(
      prompt,
      promptOrigin,
    );
  
    return {
      content: [
        {
          type: 'text',
          text: `${promptOriginKey}: ${promptOrigin}
  
  ${promptTemplateKey}: ${promptObject.template}
  
  ${contextSchemaKey}: ${JSON.stringify(promptObject.contextSchema, null, 2)}
  
  ${modelKey}: ${model}
  
  NEXT STEP:
  - Immediately call the \`${PromptWorkbenchToolName.recommend_prompt_template_tests}\` tool with:
    - template: the \`${promptTemplateKey}\` above
    - ${contextSchemaKey}: the \`${contextSchemaKey}\` above
    - ${promptOriginKey}: the \`${promptOriginKey}\` above
    - ${modelKey}: the \`${modelKey}\` above
    - ${temperatureKey}: the \`${temperatureKey}\` above
  `,
        },
      ],
    };
  };

• src/tools/createPromptTemplate/inputSchema.ts:8-31 (schema)

  Zod input schema defining parameters: prompt (string), promptOrigin (enum), model (string, default), temperature (number, default).

  export const createPromptTemplateInputSchema = z.object({
    prompt: z
      .string()
      .describe(
        "The user's application, feature, or product requirements that will be used to generate a prompt template. Alternatively, a pre-existing prompt or prompt template can be provided if a user wants to test, evaluate, or modify it. (Can be a multi-line string.)",
      ),
    promptOrigin: z
      .nativeEnum(PromptOrigin)
      .describe(
        `The origin of the prompt - either "${PromptOrigin.codebase}" for existing prompts from the codebase, or "${PromptOrigin.requirements}" for new prompts from requirements.`,
      ),
    model: z
      .string()
      .default(defaultModel)
      .describe(
        `The model that the prompt template will be tested against. Explicitly specify the model if it can be inferred from the codebase. Otherwise, defaults to \`${defaultModel}\`.`,
      ),
    temperature: z
      .number()
      .default(defaultTemperature)
      .describe(
        `The temperature of the prompt template. Explicitly specify the temperature if it can be inferred from the codebase. Otherwise, defaults to ${defaultTemperature}.`,
      ),
  });

• src/tools/createPromptTemplate/tool.ts:22-73 (registration)

  Tool object registration defining name 'create_prompt_template', detailed description, and references inputSchema.

  export const createPromptTemplateTool = {
    name: PromptWorkbenchToolName.create_prompt_template,
    description: `
    ABOUT THIS TOOL:
    - This tool is part of a toolchain that generates and provides test cases for a prompt template.
    - This tool helps an AI assistant to generate a prompt template based on one of the following:
      1. feature requirements defined by a user - in which case the tool will generate a new prompt template based on the feature requirements.
      2. a pre-existing prompt or prompt template that a user wants to test, evaluate, or modify - in which case the tool will convert it into a more structured and testable prompt template while leaving the original prompt language relatively unchanged.
    - This tool will return a structured prompt template (e.g. \`${templateKey}\`) along with a context schema (e.g. \`${contextSchemaKey}\`) that defines the expected input parameters for the prompt template.
    - In some cases, a user will want to add test coverage for ALL of the prompts in a given application. In these cases, the AI agent should use this tool to generate a prompt template for each prompt in the application, and should check the entire application for AI prompts that are not already covered by a prompt template in the \`${promptsOutputDirectory}\` directory.
  
    WHEN SHOULD THIS TOOL BE TRIGGERED?
    - This tool should be triggered whenever the user provides requirements for a new AI-enabled application or a new AI-enabled feature of an existing  application (i.e. one that requires a prompt request to an LLM or any AI model).
    - This tool should also be triggered if the user provides a pre-existing prompt or prompt template from their codebase that they want to test, evaluate, or modify.
    - This tool should be triggered even if there are pre-existing files in the \`${promptsOutputDirectory}\` directory with the \`${fileNameTemplate}\` convention (e.g. \`${fileNameExample1}\`, \`${fileNameExample2}\`, \`${fileNameExample3}\`, etc.). Similar files should NEVER be generated directly by the AI agent. Instead, the AI agent should use this tool to first generate a new prompt template.
  
    PARAMETERS:
    - ${paramsKey}: object
      - ${promptKey}: string (the feature requirements or pre-existing prompt/prompt template that will be used to generate a prompt template. Can be a multi-line string.)
      - ${promptOriginKey}: "${PromptOrigin.codebase}" | "${PromptOrigin.requirements}" (indicates whether the prompt comes from an existing codebase or from new requirements)
      - ${modelKey}: string (the model that the prompt template will be tested against. Explicitly specify the model if it can be inferred from the codebase. Otherwise, defaults to \`${defaultModel}\`.)
      - ${temperatureKey}: number (the temperature of the prompt template. Explicitly specify the temperature if it can be inferred from the codebase. Otherwise, defaults to ${defaultTemperature}.)
  
    EXAMPLE USAGE (from new requirements):
    {
      "${paramsKey}": {
        "${promptKey}": "Create an app that takes any topic and an age (in years), then renders a 1-minute bedtime story for a person of that age.",
        "${promptOriginKey}": "${PromptOrigin.requirements}"
        "${modelKey}": "${defaultModel}"
        "${temperatureKey}": 1.0
      }
    }
  
    EXAMPLE USAGE (from pre-existing prompt/prompt template in codebase):
    {
      "${paramsKey}": {
        "${promptKey}": "The user wants a bedtime story about {{topic}} for a person of age {{age}} years old. Please craft a captivating tale that captivates their imagination and provides a delightful bedtime experience.",
        "${promptOriginKey}": "${PromptOrigin.codebase}"
        "${modelKey}": "claude-3-5-sonnet-latest"
        "${temperatureKey}": 0.7
      }
    }
  
    TOOL OUTPUT INSTRUCTIONS:
    - The tool will return...
      - a \`${templateKey}\` that reformulates the user's prompt into a more structured format.
      - a \`${contextSchemaKey}\` that defines the expected input parameters for the template.
      - a \`${promptOriginKey}\` that indicates whether the prompt comes from an existing prompt or prompt template in the user's codebase or from new requirements.
    - The tool output -- the \`${templateKey}\`, \`${contextSchemaKey}\`, and \`${promptOriginKey}\` -- will also be used as input to the \`${PromptWorkbenchToolName.recommend_prompt_template_tests}\` tool to generate a list of recommended tests that can be used to test the prompt template.
    `,
    inputSchema: createPromptTemplateInputSchema,
  };

• src/circleci-tools.ts:30-44 (registration)

  Registration of createPromptTemplateTool in the main CCI_TOOLS array for MCP tools.

  export const CCI_TOOLS = [
    getBuildFailureLogsTool,
    getFlakyTestLogsTool,
    getLatestPipelineStatusTool,
    getJobTestResultsTool,
    configHelperTool,
    createPromptTemplateTool,
    recommendPromptTemplateTestsTool,
    runPipelineTool,
    listFollowedProjectsTool,
    runEvaluationTestsTool,
    rerunWorkflowTool,
    analyzeDiffTool,
    runRollbackPipelineTool,
  ];

• src/circleci-tools.ts:58-72 (registration)

  Mapping of tool name 'create_prompt_template' to its handler function in CCI_HANDLERS.

  export const CCI_HANDLERS = {
    get_build_failure_logs: getBuildFailureLogs,
    find_flaky_tests: getFlakyTestLogs,
    get_latest_pipeline_status: getLatestPipelineStatus,
    get_job_test_results: getJobTestResults,
    config_helper: configHelper,
    create_prompt_template: createPromptTemplate,
    recommend_prompt_template_tests: recommendPromptTemplateTests,
    run_pipeline: runPipeline,
    list_followed_projects: listFollowedProjects,
    run_evaluation_tests: runEvaluationTests,
    rerun_workflow: rerunWorkflow,
    analyze_diff: analyzeDiff,
    run_rollback_pipeline: runRollbackPipeline,
  } satisfies ToolHandlers;