You want to send the phone number as query param , to do that you must first have a variable have this phone number , here you are using the variable phone_number , but dosen't exit on this call , you didn't give it a value or set it up , so there is not value to replace , that's what the agent send the query as it as variable now , not the value since there is not value

the solution

use this variable instead of {{phone_number}}

not working - /api/find-patient?filter=%7B%7Buser_number%7D%7D still did not get substituted. Here is the instruction for the agent. and the query params im using ### 1. The "Find Patient" Sequence (Authentication) REQUIRED: Before booking, canceling, or rescheduling for an existing patient, you MUST identify them first. CRITICAL: The find_patient tool returns ALL contacts in the database (hundreds or thousands). You MUST search through the entire list to find the one matching the caller's phone number. DO NOT just check the first contact. Steps: 1. Ask for Phone Number (Primary method) - "May I have your phone number to look up your account?" 2. Format the Phone Number - CRITICAL: - ALWAYS remove ALL dashes, spaces, parentheses, and any other formatting - Extract ONLY the 10 digits - Examples: - Patient says: "954-729-5697" → You use:

9547295697

- Patient says: "(954) 729-5697" → You use:

9547295697

- Patient says: "954 729 5697" → You use:

9547295697

- Patient says: "nine five four, seven two nine, five six nine seven" → You use:

9547295697

3. Call

find_patient

- CRITICAL: You MUST pass the phone number in a parameter called

filter

- The parameter name is

filter

and the value is the 10-digit phone number with no formatting - Example tool call format:

{"filter": "9547295697"}

- DO NOT use parameter names like

phone_number

or

phone

- it MUST be called

filter

- Pass the phone number as digits only (no dashes, spaces, or formatting) https://cdn.discordapp.com/attachments/1450867178906714123/1450879479487533219/Screenshot_2025-12-17_at_10.56.52_AM.png?ex=6944244f&is=6942d2cf&hm=85e3c4859e4aedb76429a659c064b92f790e9a68396e017a37ee04cfd114c3a4&

how would i define this variable so the sytem knows to substitute its still not doing this i hear what your saying but this isnt working

Yes, you need to used a phone call to work

ok last question. Ive defined the variable in extracted variables. Ive listed it properly in the query i believe., and still passed as phone_number. does this just not work at all in text testing?

@Omar Ashraf | Community Lead tested this on voice also not working man

int eh query params is the variable supposed to be in single or double curly braces? {phone_number or {{phone_number}}... im just guessing at this point what else could be wrong

in the tool log i can see my number this is whats so confusing... in the logs for my api its showing the text not substituted...

@Omar Ashraf | Community Lead hey Omar, having another issue with tool call not appending the variable into the url. call id - call_1796f2c8361d9e3a0d11c6b9ef8 i have the appointment_id se up as an extracted variable as you advised. I can see the payload the data that we need is there. My url for the rescehdule appointment is 100% correct, however its not passing the appointment Id variable though... im saving it both in extracted variables as a custom function and as a response variable from check appointments. this needs to be at the path level so i cannot use it as a query param. Any suggestions on this?

@Colin - Integrations @ Retell AI would you be able to check this out?