Get a prompt from an AgentCore gateway
To get a specific prompt, make a POST request to the gateway’s MCP endpoint and specify prompts/get as the method in the request body, name of the prompt, and the arguments:
POST /mcp HTTP/1.1
Host: ${GatewayEndpoint}
Content-Type: application/json
Authorization: ${Authorization header}
${RequestBody}
Replace the following values:
-
${GatewayEndpoint} – The URL of the gateway, as provided in the response of the CreateGateway API.
-
${Authorization header} – The authorization credentials from the identity provider when you set up inbound authorization.
-
${RequestBody} – The JSON payload of the request body, as specified in Getting a prompt in the Model Context Protocol (MCP) . Include prompts/get as the method and include the name of the prompt and its arguments.
The response returns the rendered prompt as an array of messages, each with a role and content.
The prompts/get operation proxies the request live to the downstream MCP server. The prompt name must include the target prefix (for example, myTarget___myPrompt).
Code samples for getting a prompt
To see examples of getting a prompt from the gateway, select one of the following methods:
Example
- curl
-
-
The following curl request shows an example request to get a prompt called myTarget___code_review through a gateway with the ID mygateway-abcdefghij.
curl -X POST \
https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
-d '{
"jsonrpc": "2.0",
"id": "get-prompt-request",
"method": "prompts/get",
"params": {
"name": "myTarget___code_review",
"arguments": {
"language": "python",
"code": "print(\"hello\")"
}
}
}'
- Python requests package
-
-
import requests
import json
def get_prompt(gateway_url, access_token, prompt_name, arguments):
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {access_token}"
}
payload = {
"jsonrpc": "2.0",
"id": "get-prompt-request",
"method": "prompts/get",
"params": {
"name": prompt_name,
"arguments": arguments
}
}
response = requests.post(gateway_url, headers=headers, json=payload)
return response.json()
# Example usage
gateway_url = "https://${GatewayEndpoint}/mcp" # Replace with your actual gateway endpoint
access_token = "${AccessToken}" # Replace with your actual access token
result = get_prompt(
gateway_url,
access_token,
"myTarget___code_review", # Replace with {targetName}___{promptName}
{"language": "python", "code": "print('hello')"}
)
print(json.dumps(result, indent=2))
- MCP Client
-
-
from mcp import ClientSession
from mcp.client.streamable_http import streamablehttp_client
import asyncio
async def execute_mcp(
url,
token,
prompt_name,
prompt_arguments,
headers=None
):
default_headers = {
"Authorization": f"Bearer {token}"
}
headers = {**default_headers, **(headers or {})}
async with streamablehttp_client(
url=url,
headers=headers,
) as (
read_stream,
write_stream,
callA,
):
async with ClientSession(read_stream, write_stream) as session:
# 1. Perform initialization handshake
print("Initializing MCP...")
_init_response = await session.initialize()
print(f"MCP Server Initialize successful! - {_init_response}")
# 2. Get specific prompt
print(f"Getting prompt: {prompt_name}")
prompt_response = await session.get_prompt(
name=prompt_name,
arguments=prompt_arguments
)
print(f"Prompt response: {prompt_response}")
return prompt_response
async def main():
url = "https://${GatewayEndpoint}/mcp"
token = "your_bearer_token_here"
prompt_name = "myTarget___code_review"
prompt_arguments = {
"language": "python",
"code": "print('hello')"
}
await execute_mcp(
url=url,
token=token,
prompt_name=prompt_name,
prompt_arguments=prompt_arguments
)
if __name__ == "__main__":
asyncio.run(main())
- LangGraph MCP Client
-
-
NOTE: LangGraph MCP adapter prompt support may vary. Use the MCP Client approach above for the most reliable prompts/get implementation.
import asyncio
from mcp import ClientSession
from mcp.client.streamable_http import streamablehttp_client
async def get_prompt(url, token, prompt_name, arguments):
headers = {"Authorization": f"Bearer {token}"}
async with streamablehttp_client(url=url, headers=headers) as (
read_stream, write_stream, callA
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
response = await session.get_prompt(
name=prompt_name,
arguments=arguments
)
for message in response.messages:
print(f"{message.role}: {message.content}")
asyncio.run(get_prompt(
"https://${GatewayEndpoint}/mcp",
"${AccessToken}",
"myTarget___code_review",
{"language": "python", "code": "print('hello')"}
))
Errors
The prompts/get operation can return the following types of errors:
-
Errors returned as part of the HTTP status code:
-
AuthenticationError
-
The request failed due to invalid authentication credentials.
HTTP Status Code : 401
-
AuthorizationError
-
The caller does not have permission to get the prompt.
HTTP Status Code : 403
-
ResourceNotFoundError
-
The specified prompt does not exist.
HTTP Status Code : 404
-
ValidationError
-
The provided arguments do not satisfy the prompt’s required arguments.
HTTP Status Code : 400
-
InternalServerError
-
An internal server error occurred.
HTTP Status Code : 500
-
MCP errors. For more information about these types of errors, see Prompts in the Model Context Protocol (MCP) documentation.
