# configurations
.idea
.vscode

# crawlee and apify storage folders
apify_storage
crawlee_storage
storage

# installed files
node_modules

# git folder
.git

# dist folder
dist

INPUT.json

.gitignore

# This file tells Git which files shouldn't be added to source control

.idea
.vscode
.zed
storage
apify_storage
crawlee_storage
node_modules
dist
tsconfig.tsbuildinfo
storage/*
!storage/key_value_stores
storage/key_value_stores/*
!storage/key_value_stores/default
storage/key_value_stores/default/*
!storage/key_value_stores/default/INPUT.json

# Added by Apify CLI
.venv

INPUT.json

LICENSE

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   END OF TERMS AND CONDITIONS

   APPENDIX: How to apply the Apache License to your work.

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   Licensed under the Apache License, Version 2.0 (the "License");
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   See the License for the specific language governing permissions and
   limitations under the License.

biome.json

{
    "$schema": "https://biomejs.dev/schemas/1.9.4/schema.json",
    "vcs": {
        "enabled": false,
        "clientKind": "git",
        "useIgnoreFile": false
    },
    "files": {
        "ignoreUnknown": false,
        "ignore": []
    },
    "formatter": {
        "enabled": true,
        "indentStyle": "space",
        "indentWidth": 4
    },
    "organizeImports": {
        "enabled": true
    },
    "linter": {
        "enabled": true,
        "rules": {
            "recommended": true
        }
    },
    "javascript": {
        "formatter": {
            "quoteStyle": "double"
        }
    }
}

package.json

{
    "name": "mcp-stress-tester",
    "version": "0.0.1",
    "type": "module",
    "description": "This is an example of an Apify actor.",
    "engines": {
        "node": ">=18.0.0"
    },
    "bin": {
        "mcp-stress-tester": "./dist/index.js"
    },
    "files": ["dist", "LICENSE", "README.md"],
    "dependencies": {
        "@modelcontextprotocol/sdk": "^1.12.3",
        "@types/yargs": "^17.0.33",
        "apify": "^3.4.2",
        "yargs": "^18.0.0",
        "yargs-parser": "^22.0.0"
    },
    "devDependencies": {
        "@apify/tsconfig": "^0.1.1",
        "@biomejs/biome": "1.9.4",
        "tsx": "^4.19.4",
        "typescript": "^5.8.3"
    },
    "scripts": {
        "build": "tsc",
        "format": "npx biome format",
        "format:fix": "npx biome format --write",
        "lint": "npx biome lint",
        "lint:fix": "npx biome lint --write",
        "test": "echo \"Error: oops, the actor has no tests yet, sad!\" && exit 1"
    },
    "author": "It's not you it's me",
    "license": "ISC"
}

tsconfig.json

{
    "extends": "@apify/tsconfig",
    "compilerOptions": {
        "module": "NodeNext",
        "moduleResolution": "NodeNext",
        "target": "ES2022",
        "outDir": "dist",
        "noUnusedLocals": false,
        "skipLibCheck": true,
        "lib": ["DOM"]
    },
    "include": ["./src/**/*"]
}

.actor/Dockerfile

FROM node:22-alpine AS builder

# Copy just package.json and package-lock.json
# to speed up the build using Docker layer cache.
COPY package*.json ./

# Install all dependencies. Don't audit to speed up the installation.
RUN npm install --include=dev --audit=false

# Next, copy the source files using the user set
# in the base image.
COPY . ./

# Install all dependencies and build the project.
# Don't audit to speed up the installation.
RUN npm run build

# Create final image
FROM node:22-alpine

# Create and run as a non-root user.
RUN adduser -h /home/apify -D apify
# Create app directory
RUN mkdir -p /home/apify/app
WORKDIR /home/apify/app

# Copy built JS files from builder image
COPY --from=builder /dist ./dist

# Copy just package.json and package-lock.json
# to speed up the build using Docker layer cache.
COPY package*.json ./
RUN chown -R apify:apify /home/apify/app
USER apify

# Install NPM packages, skip optional and development dependencies to
# keep the image small. Avoid logging too much and print the dependency
# tree for debugging
RUN npm --quiet set progress=false \
    && npm install --omit=dev --omit=optional \
    && echo "Installed NPM packages:" \
    && (npm list --omit=dev --all || true) \
    && echo "Node.js version:" \
    && node --version \
    && echo "NPM version:" \
    && npm --version \
    && rm -r ~/.npm

# Tell Node.js this is a production environemnt
ENV NODE_ENV=production

# Enable Node.js process to use a lot of memory (Actor has limit of 32GB)
# Increases default size of headers. The original limit was 80kb, but from node 10+ they decided to lower it to 8kb.
# However they did not think about all the sites there with large headers,
# so we put back the old limit of 80kb, which seems to work just fine.
ENV NODE_OPTIONS="--max_old_space_size=30000 --max-http-header-size=80000"

# Run the image.
CMD ["node", "dist/main.js", "--silent"]

.actor/actor.json

{
    "actorSpecification": 1,
    "name": "mcp-stress-tester",
    "title": "MCP Stress Tester",
    "description": "A simple MCP Stress Tester client Actor for stress-testing your MCP server.",
    "version": "0.1",
    "meta": {
        "templateId": "ts-start"
    },
    "input": "./input_schema.json",
    "dockerfile": "./Dockerfile"
}

.actor/input_schema.json

{
    "title": "MCP Stress Tester",
    "type": "object",
    "schemaVersion": 1,
    "properties": {
        "target": {
            "title": "Target URL",
            "type": "string",
            "description": "Specify the target URL",
            "editor": "textfield"
        },
        "sse": {
            "title": "Enable SSE",
            "type": "boolean",
            "description": "Enable SSE switch",
            "default": false,
            "editor": "checkbox"
        },
        "token": {
            "title": "Bearer token",
            "type": "string",
            "description": "Optional Bearer token for authentication",
            "editor": "textfield",
            "isSecret": true
        },
        "mode": {
            "title": "Test Mode",
            "type": "string",
            "description": "Test mode: 'normal' (persistent clients that continuously send operations) or 'swarm' (constantly creating/closing clients to simulate dynamic load patterns)",
            "default": "normal",
            "enum": ["normal", "swarm"],
            "enumTitles": ["Normal", "Swarm"],
            "editor": "select"
        },
        "clients": {
            "title": "Number of clients",
            "type": "integer",
            "description": "In normal mode: total number of concurrent client connections to maintain. In swarm mode: number of clients to create in each batch.",
            "default": 10,
            "minimum": 1,
            "editor": "number"
        },
        "clientsCreationBatchSize": {
            "title": "Clients creation batch size",
            "type": "integer",
            "description": "In normal mode: number of clients to create in each initialization batch (to avoid overwhelming the server). In swarm mode: this parameter is ignored.",
            "default": 5,
            "minimum": 1,
            "editor": "number"
        },
        "opsRate": {
            "title": "Operations rate",
            "type": "integer",
            "description": "In normal mode: operations (list tools) per minute per client. In swarm mode: this parameter is ignored as each client performs exactly one operation before being closed.",
            "default": 30,
            "minimum": 1,
            "editor": "number"
        },
        "swarmInterval": {
            "title": "Swarm interval (ms)",
            "type": "integer",
            "description": "Interval in ms between swarm batches (only used in swarm mode). Controls how frequently new client batches are created and destroyed.",
            "default": 5000,
            "minimum": 100,
            "editor": "number"
        },
        "maxRetries": {
            "title": "Maximum retries",
            "type": "integer",
            "description": "Maximum number of retries for client creation",
            "default": 5,
            "minimum": 0,
            "editor": "number"
        },
        "initialBackoffMs": {
            "title": "Initial backoff (ms)",
            "type": "integer",
            "description": "Initial backoff time in milliseconds",
            "default": 100,
            "minimum": 1,
            "editor": "number"
        },
        "maxBackoffMs": {
            "title": "Maximum backoff (ms)",
            "type": "integer",
            "description": "Maximum backoff time in milliseconds",
            "default": 10000,
            "minimum": 1,
            "editor": "number"
        },
        "backoffFactor": {
            "title": "Backoff factor",
            "type": "integer",
            "description": "Factor by which to increase backoff time after each retry",
            "default": 2,
            "minimum": 1,
            "editor": "number"
        }
    },
    "required": ["target"]
}

src/index.ts

1#!/usr/bin/env node
2import { log } from "apify";
3import yargs from "yargs";
4import { hideBin } from "yargs/helpers";
5import { runNormalMode, runSwarmMode } from "./shared.js";
6
7// Interface for input arguments
8interface InputArgs {
9    target: string;
10    sse: boolean;
11    clients: number;
12    clientsCreationBatchSize: number;
13    opsRate: number;
14    maxRetries: number;
15    initialBackoffMs: number;
16    maxBackoffMs: number;
17    backoffFactor: number;
18    mode: "normal" | "swarm";
19    swarmInterval: number;
20}
21
22// Parse command line arguments using yargs
23const argv = yargs(hideBin(process.argv))
24    .option("target", {
25        alias: "t",
26        type: "string",
27        description: "Target MCP server URL",
28        demandOption: true,
29    })
30    .option("sse", {
31        type: "boolean",
32        description: "Enable SSE transport",
33        default: false,
34    })
35    .option("clients", {
36        alias: "c",
37        type: "number",
38        description:
39            "In normal mode: total number of concurrent client connections to maintain. In swarm mode: number of clients to create in each batch.",
40        default: 10,
41    })
42    .option("clientsCreationBatchSize", {
43        type: "number",
44        description:
45            "In normal mode: number of clients to create in each initialization batch (to avoid overwhelming the server). In swarm mode: this parameter is ignored.",
46        default: 5,
47    })
48    .option("opsRate", {
49        alias: "r",
50        type: "number",
51        description:
52            "In normal mode: operations (list tools) per minute per client. In swarm mode: this parameter is ignored as each client performs exactly one operation before being closed.",
53        default: 60,
54    })
55    .option("maxRetries", {
56        type: "number",
57        description: "Maximum number of retries",
58        default: 3,
59    })
60    .option("initialBackoffMs", {
61        type: "number",
62        description: "Initial backoff in milliseconds",
63        default: 100,
64    })
65    .option("maxBackoffMs", {
66        type: "number",
67        description: "Maximum backoff in milliseconds",
68        default: 10000,
69    })
70    .option("backoffFactor", {
71        type: "number",
72        description: "Backoff factor",
73        default: 2,
74    })
75    .option("mode", {
76        type: "string",
77        description:
78            "Test mode: 'normal' (persistent clients that continuously send operations) or 'swarm' (constantly creating/closing clients to simulate dynamic load patterns)",
79        choices: ["normal", "swarm"],
80        default: "normal",
81    })
82    .option("swarmInterval", {
83        type: "number",
84        description:
85            "Interval in ms between swarm batches (only used in swarm mode). Controls how frequently new client batches are created and destroyed.",
86        default: 5000,
87    })
88    .help()
89    .alias("help", "h")
90    .version()
91    .alias("version", "v")
92    .parse();
93
94const {
95    target: targetUrl,
96    sse: sseEnabled,
97    clients: numClients,
98    clientsCreationBatchSize,
99    opsRate,
100    maxRetries,
101    initialBackoffMs,
102    maxBackoffMs,
103    backoffFactor,
104    mode,
105    swarmInterval,
106}: InputArgs = argv as InputArgs;
107
108async function main() {
109    log.info(`Starting benchmark with the following configuration:
110- Target URL: ${targetUrl}
111- SSE Enabled: ${sseEnabled}
112- Mode: ${mode}
113- Number of Clients: ${numClients}
114- Clients Creation Batch Size: ${clientsCreationBatchSize}
115- Operations Per Minute: ${opsRate}
116- Max Retries: ${maxRetries}
117- Initial Backoff: ${initialBackoffMs}ms
118- Max Backoff: ${maxBackoffMs}ms
119- Backoff Factor: ${backoffFactor}
120${mode === "swarm" ? `- Swarm Interval: ${swarmInterval}ms` : ""}
121`);
122
123    if (mode === "normal") {
124        await runNormalMode(
125            targetUrl,
126            process.env.APIFY_TOKEN as string,
127            sseEnabled,
128            numClients,
129            clientsCreationBatchSize,
130            opsRate,
131            maxRetries,
132            initialBackoffMs,
133            maxBackoffMs,
134            backoffFactor,
135        );
136    } else if (mode === "swarm") {
137        await runSwarmMode(
138            targetUrl,
139            process.env.APIFY_TOKEN as string,
140            sseEnabled,
141            numClients,
142            swarmInterval,
143            maxRetries,
144            initialBackoffMs,
145            maxBackoffMs,
146            backoffFactor,
147        );
148    } else {
149        log.error(`Unknown mode: ${mode}`);
150        process.exit(1);
151    }
152}
153
154main().catch((error) => {
155    log.error("Error in main execution:", error);
156    process.exit(1);
157});

src/main.ts

1import { Actor, log } from "apify";
2import { runNormalMode, runSwarmMode } from "./shared.js";
3
4await Actor.init();
5
6interface Input {
7    target: string;
8    sse: boolean;
9    token: string;
10    clients: number;
11    clientsCreationBatchSize: number;
12    opsRate: number;
13    maxRetries: number;
14    initialBackoffMs: number;
15    maxBackoffMs: number;
16    backoffFactor: number;
17    mode: "normal" | "swarm";
18    swarmInterval: number;
19}
20// Structure of input is defined in input_schema.json
21const input = await Actor.getInput<Input>();
22if (!input) throw new Error("Input is missing!");
23const {
24    target: targetUrl,
25    sse: sseEnabled,
26    token,
27    clients: numClients,
28    clientsCreationBatchSize,
29    opsRate,
30    maxRetries,
31    initialBackoffMs,
32    maxBackoffMs,
33    backoffFactor,
34    mode = "normal",
35    swarmInterval = 5000,
36} = input;
37
38log.info(`Starting benchmark with the following configuration:
39- Target URL: ${targetUrl}
40- SSE Enabled: ${sseEnabled}
41- Mode: ${mode}
42${mode === "normal" ? `- Number of Clients: ${numClients} (total concurrent connections)` : `- Clients Per Batch: ${numClients}`}
43${mode === "normal" ? `- Clients Creation Batch Size: ${clientsCreationBatchSize} (for initialization)` : ""}
44${mode === "normal" ? `- Operations Per Minute Per Client: ${opsRate}` : ""}
45- Max Retries: ${maxRetries}
46- Initial Backoff: ${initialBackoffMs}ms
47- Max Backoff: ${maxBackoffMs}ms
48- Backoff Factor: ${backoffFactor}
49${mode === "swarm" ? `- Swarm Interval: ${swarmInterval}ms (between batches)` : ""}
50`);
51
52if (mode === "normal") {
53    await runNormalMode(
54        targetUrl,
55        token,
56        sseEnabled,
57        numClients,
58        clientsCreationBatchSize,
59        opsRate,
60        maxRetries,
61        initialBackoffMs,
62        maxBackoffMs,
63        backoffFactor,
64    );
65} else if (mode === "swarm") {
66    await runSwarmMode(
67        targetUrl,
68        token,
69        sseEnabled,
70        numClients,
71        swarmInterval,
72        maxRetries,
73        initialBackoffMs,
74        maxBackoffMs,
75        backoffFactor,
76    );
77} else {
78    log.error(`Unknown mode: ${mode}`);
79    process.exit(1);
80}
81
82// Gracefully exit the Actor process. It's recommended to quit all Actors with an exit().
83await Actor.exit();

src/shared.ts

1import type { Client } from "@modelcontextprotocol/sdk/client/index.js";
2import { createClient } from "./utils.js";
3import { log } from "apify";
4import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
5
6export async function runNormalMode(
7    targetUrl: string,
8    token: string,
9    sseEnabled: boolean,
10    numClients: number,
11    clientsCreationBatchSize: number,
12    opsRate: number,
13    maxRetries: number,
14    initialBackoffMs: number,
15    maxBackoffMs: number,
16    backoffFactor: number,
17) {
18    const numBatches = Math.floor(numClients / clientsCreationBatchSize);
19
20    const clients: Client[] = [];
21    for (let i = 0; i < numBatches; i++) {
22        const batch = await Promise.all(
23            Array.from({ length: clientsCreationBatchSize }, () =>
24                createClient({
25                    targetUrl,
26                    sseEnabled,
27                    token,
28                    maxRetries,
29                    initialBackoffMs,
30                    maxBackoffMs,
31                    backoffFactor,
32                }),
33            ),
34        );
35        log.info(
36            `Created client batch ${i + 1} of ${Math.ceil(numClients / clientsCreationBatchSize)}`,
37        );
38        clients.push(...batch);
39    }
40    if (numClients % clientsCreationBatchSize !== 0) {
41        const remainingClients = numClients % clientsCreationBatchSize;
42        const batch = await Promise.all(
43            Array.from({ length: remainingClients }, () =>
44                createClient({
45                    targetUrl,
46                    sseEnabled,
47                    token,
48                    maxRetries,
49                    initialBackoffMs,
50                    maxBackoffMs,
51                    backoffFactor,
52                }),
53            ),
54        );
55        log.info(`Created final client batch of ${remainingClients}`);
56        clients.push(...batch);
57    }
58
59    log.info(
60        `Successfully created ${clients.length} clients. Starting benchmark operations...`,
61    );
62
63    const startTime = Date.now();
64    let operationsCompleted = 0;
65    let operationsFailed = 0;
66
67    const intervalIDs = clients.map((_, index) => {
68        return setInterval(async () => {
69            try {
70                await clients[index].listTools(undefined, {
71                    timeout: 60000,
72                });
73                operationsCompleted++;
74                if (operationsCompleted % 100 === 0) {
75                    const elapsedSeconds = (Date.now() - startTime) / 1000;
76                    const opsPerSec = operationsCompleted / elapsedSeconds;
77                    log.info(
78                        `Completed ${operationsCompleted} operations (${(opsPerSec).toFixed(2)} ops/sec), failed: ${operationsFailed}`,
79                    );
80                }
81            } catch (error) {
82                operationsFailed++;
83                log.error(`Error listing tools for client ${index}: ${error}`);
84            }
85        }, 60000 / opsRate);
86    });
87
88    process.on("SIGINT", async () => {
89        log.info("Received abort. Closing clients...");
90        for (const id of intervalIDs) {
91            clearInterval(id);
92        }
93
94        const elapsedSeconds = (Date.now() - startTime) / 1000;
95        log.info(`
96Benchmark Summary:
97- Total operations completed: ${operationsCompleted}
98- Total operations failed: ${operationsFailed}
99- Average throughput: ${(operationsCompleted / elapsedSeconds).toFixed(2)} ops/sec
100- Total runtime: ${elapsedSeconds.toFixed(2)} seconds
101`);
102
103        await Promise.all(clients.map((client) => client.close()))
104            .then(() => {
105                log.info("All clients closed.");
106                process.exit(0);
107            })
108            .catch((error) => {
109                log.error("Error closing clients:", error);
110                process.exit(1);
111            });
112    });
113
114    while (true) {
115        await new Promise((resolve) => setTimeout(resolve, 1000));
116    }
117}
118
119export async function runSwarmMode(
120    targetUrl: string,
121    token: string,
122    sseEnabled: boolean,
123    numClients: number,
124    swarmInterval: number,
125    maxRetries: number,
126    initialBackoffMs: number,
127    maxBackoffMs: number,
128    backoffFactor: number,
129) {
130    const startTime = Date.now();
131    let batchesCompleted = 0;
132    let clientsCreated = 0;
133    let operationsCompleted = 0;
134    let operationsFailed = 0;
135    let running = true;
136
137    // In swarm mode, we use the numClients parameter for each batch
138    const batchSize = numClients;
139
140    process.on("SIGINT", async () => {
141        log.info("Received abort. Stopping swarm mode...");
142        running = false;
143
144        const elapsedSeconds = (Date.now() - startTime) / 1000;
145        log.info(`
146Swarm Benchmark Summary:
147- Total batches completed: ${batchesCompleted}
148- Total clients created: ${clientsCreated}
149- Total operations completed: ${operationsCompleted}
150- Total operations failed: ${operationsFailed}
151- Average client creation rate: ${(clientsCreated / elapsedSeconds).toFixed(2)} clients/sec
152- Average operation rate: ${(operationsCompleted / elapsedSeconds).toFixed(2)} ops/sec
153- Total runtime: ${elapsedSeconds.toFixed(2)} seconds
154`);
155        process.exit(0);
156    });
157
158    while (running) {
159        try {
160            // Create a batch of clients
161            log.info(
162                `Creating batch #${batchesCompleted + 1} with ${batchSize} clients...`,
163            );
164            const clients = await Promise.all(
165                Array.from({ length: batchSize }, () =>
166                    createClient({
167                        targetUrl,
168                        sseEnabled,
169                        token,
170                        maxRetries,
171                        initialBackoffMs,
172                        maxBackoffMs,
173                        backoffFactor,
174                    }),
175                ),
176            );
177            clientsCreated += clients.length;
178
179            // Have each client list tools
180            log.info(
181                `Batch #${batchesCompleted + 1}: Listing tools with ${clients.length} clients...`,
182            );
183            const results = await Promise.allSettled(
184                clients.map((client) =>
185                    client.listTools(undefined, { timeout: 60000 }),
186                ),
187            );
188
189            // Count successes and failures
190            const successes = results.filter(
191                (r) => r.status === "fulfilled",
192            ).length;
193            const failures = results.filter(
194                (r) => r.status === "rejected",
195            ).length;
196            operationsCompleted += successes;
197            operationsFailed += failures;
198
199            // Close all clients
200            log.info(
201                `Batch #${batchesCompleted + 1}: Closing ${clients.length} clients...`,
202            );
203            await Promise.all(
204                clients.map((client) => {
205                    if (
206                        client.transport instanceof
207                        StreamableHTTPClientTransport
208                    ) {
209                        return client.transport.terminateSession();
210                    }
211                    return null;
212                }),
213            );
214            await Promise.all(clients.map((client) => client.close()));
215
216            batchesCompleted++;
217
218            // Log progress periodically
219            if (batchesCompleted % 5 === 0) {
220                const elapsedSeconds = (Date.now() - startTime) / 1000;
221                log.info(`
222Swarm Progress:
223- Batches completed: ${batchesCompleted}
224- Clients created: ${clientsCreated}
225- Operations completed: ${operationsCompleted} (${(operationsCompleted / elapsedSeconds).toFixed(2)} ops/sec)
226- Operations failed: ${operationsFailed}
227- Runtime: ${elapsedSeconds.toFixed(2)} seconds
228`);
229            }
230
231            // Wait before creating the next batch
232            await new Promise((resolve) => setTimeout(resolve, swarmInterval));
233        } catch (error) {
234            log.error(`Error in swarm batch: ${error}`);
235        }
236    }
237}

src/utils.ts

1import { Client } from "@modelcontextprotocol/sdk/client/index.js";
2import { SSEClientTransport } from "@modelcontextprotocol/sdk/client/sse.js";
3import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
4
5export type CreateClientOptions = {
6    targetUrl: string;
7    sseEnabled: boolean;
8    token?: string;
9    maxRetries?: number;
10    initialBackoffMs?: number;
11    maxBackoffMs?: number;
12    backoffFactor?: number;
13};
14
15/**
16 * Sleep for the specified number of milliseconds
17 */
18const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));
19
20/**
21 * Create a client with exponential backoff retry logic
22 */
23export async function createClient(
24    options: CreateClientOptions,
25): Promise<Client> {
26    const {
27        targetUrl,
28        sseEnabled,
29        token = "", // Default to empty string if not provided
30        maxRetries = 5,
31        initialBackoffMs = 100,
32        maxBackoffMs = 10000,
33        backoffFactor = 2,
34    } = options;
35
36    let retries = 0;
37    let backoffMs = initialBackoffMs;
38
39    while (true) {
40        try {
41            let transport: StreamableHTTPClientTransport | SSEClientTransport;
42            if (sseEnabled) {
43                transport = new SSEClientTransport(new URL(targetUrl), {
44                    requestInit: {
45                        headers: {
46                            ...(token
47                                ? { Authorization: `Bearer ${token}` }
48                                : {}),
49                        },
50                    },
51                    eventSourceInit: {
52                        // The EventSource package augments EventSourceInit with a "fetch" parameter.
53                        // You can use this to set additional headers on the outgoing request.
54                        // Based on this example: https://github.com/modelcontextprotocol/typescript-sdk/issues/118
55                        async fetch(
56                            input: Request | URL | string,
57                            init?: RequestInit,
58                        ) {
59                            const headers = new Headers(init?.headers || {});
60                            if (token)
61                                headers.set("authorization", `Bearer ${token}`);
62                            return fetch(input, { ...init, headers });
63                        },
64                        // We have to cast to "any" to use it, since it's non-standard
65                    },
66                });
67            } else {
68                transport = new StreamableHTTPClientTransport(
69                    new URL(targetUrl),
70                    {
71                        requestInit: {
72                            headers: {
73                                ...(token
74                                    ? { Authorization: `Bearer ${token}` }
75                                    : {}),
76                            },
77                        },
78                    },
79                );
80            }
81
82            const client = new Client({
83                name: "benchmark-client",
84                version: "1.0.0",
85            });
86
87            await client.connect(transport);
88            return client;
89        } catch (error) {
90            retries++;
91            if (retries > maxRetries) {
92                console.error(
93                    `Failed to create client after ${maxRetries} retries:`,
94                    error,
95                );
96                throw error;
97            }
98
99            // Add jitter to avoid thundering herd problem
100            const jitter = Math.random() * 0.3 + 0.85; // Random value between 0.85 and 1.15
101            const actualBackoff = Math.min(backoffMs * jitter, maxBackoffMs);
102
103            console.warn(
104                `Client creation failed, retrying in ${Math.round(actualBackoff)}ms (attempt ${retries}/${maxRetries})`,
105            );
106            await sleep(actualBackoff);
107
108            // Increase backoff for next attempt
109            backoffMs = Math.min(backoffMs * backoffFactor, maxBackoffMs);
110        }
111    }
112}

.github/workflows/create-release.yml

name: Create release

on:
  workflow_dispatch: # Manual trigger
    inputs:
      version:
        description: 'Release version (e.g., v0.0.1)'
        required: true
      prerelease:
        description: 'Is this a prerelease?'
        required: true
        default: false
        type: boolean

jobs:
  build-and-release:
    runs-on: ubuntu-latest

    steps:
      # Checkout the repository
      - name: Checkout code
        uses: actions/checkout@v4

      # Set up Node.js
      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'
          cache: 'npm'

      # Install dependencies
      - name: Install dependencies
        run: npm ci

      # Run linting
      - name: Lint
        run: npm run lint

      # Build the project
      - name: Build
        run: npm run build

      # Create binary executable
      - name: Make binary executable
        run: chmod +x ./dist/index.js

      # Create directory structure for packaging
      - name: Create package directory
        run: |
          mkdir -p package
          cp -r dist package/
          cp package.json package/
          cp README.md package/

      # Package with package/ prefix as tarball
      - name: Package as tarball
        run: tar -czf mcp-stress-tester-${{ github.event.inputs.version }}.tar.gz package

      # Package with package/ prefix as zip
      - name: Package as zip
        run: zip -r mcp-stress-tester-${{ github.event.inputs.version }}.zip package

      # Create GitHub release
      - name: Create Release
        uses: softprops/action-gh-release@v2
        with:
          tag_name: ${{ github.event.inputs.version }}
          name: MCP Stress Tester ${{ github.event.inputs.version }}
          body: |
            ## MCP Stress Tester ${{ github.event.inputs.version }}

            ### Installation

            ```bash
            # Install directly from GitHub release
            npm install -g https://github.com/apify/mcp-stress-tester/releases/download/${{ github.event.inputs.version }}/mcp-stress-tester-${{ github.event.inputs.version }}.tar.gz
            ```
            ```
          draft: false
          prerelease: ${{ github.event.inputs.prerelease }}
          files: |
            mcp-stress-tester-${{ github.event.inputs.version }}.tar.gz
            mcp-stress-tester-${{ github.event.inputs.version }}.zip

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