OpenPhone through One
OpenPhone is a modern business phone system that unifies VoIP calls, SMS messaging, shared numbers, and AI-powered contact management into an intuitive, cross-platform app—streamlining communication for teams and small businesses.
One exposes OpenPhone through four MCP tools. The table below carries real action ids from One's knowledge base, so for a common operation you can skip search and go straight to reading the action's parameters.
How to run an action
- Find the action in the table below, or call
search_one_platform_actions with platform open-phone if it is not listed.
- Call
get_one_action_knowledge with the action id. Do this every time, including for actions in this table. The table gives you the id, not the parameters.
- Call
execute_one_action with parameters copied from that knowledge.
Never guess a parameter name, a body field, or an enum value. The knowledge has the real schema, and a guessed field is either a 400 or a silent write of the wrong thing.
Before you start
Call list_one_integrations once and confirm OpenPhone is connected. If it is missing, the user has not connected it: say so and point them at https://app.withone.ai rather than reaching for raw HTTP.
Each connection carries an access field. If it reports {"policy": "methods", "methods": ["GET"]} the agent is read-only here, so plan a read-only answer instead of attempting a write that will be refused.
Before a write
Creates, updates, deletes and sends land on a real OpenPhone account and cannot be recalled. State the action and the specific target in one line before the first write in a task, and let the user stop you. Reads need no confirmation.
Actions
Contacts
| Action |
Method |
Path |
Action id |
| Get a Contact by ID |
GET |
/v1/contacts/{{id}} |
conn_mod_def::GJ56pIdllv0::pkGtjKXkSxCfVhh92bRihQ |
| List Contacts |
GET |
/contacts |
conn_mod_def::GJ56pUMGu4k::-07auMgORqiBhNv-fDGzXA |
| Create a Contact (Workspace) |
POST |
/contacts |
conn_mod_def::GJ56pI-gYEQ::RgRHSLhdQDiS9eaHB0GX-w |
| Delete a Contact |
DELETE |
/v1/contacts/{{id}} |
conn_mod_def::GJ56pIk_ww0::Ox_NaHQ2SxmxIPk6Z7Ka2w |
| Update a Contact by ID |
PATCH |
/v1/contacts/{{id}} |
conn_mod_def::GJ56pT78s-4::sqLHjI6_QI-t-Tu8mg72uw |
Webhooks
| Action |
Method |
Path |
Action id |
| Get a Webhook by ID |
GET |
/v1/webhooks/{{id}} |
conn_mod_def::GJ56pvjFO4s::iX_fMAKITLyKV3wTaXzx1g |
| List Webhooks (for a User) |
GET |
/v1/webhooks |
conn_mod_def::GJ56pvV-uQA::GIKIVohsQz2EZ9gyOoa1fg |
| Create a Call Summary Webhook |
POST |
/webhooks/call-summaries |
conn_mod_def::GJ56pnuYZWA::oESWSijQRuaLusj18Vy8Ag |
| Delete a Webhook by ID |
DELETE |
/v1/webhooks/{{id}} |
conn_mod_def::GJ56pnHo2yc::uGPYOolCSn29MnKC6FdfOQ |
Messages
| Action |
Method |
Path |
Action id |
| Get a Message by ID |
GET |
/v1/messages/{{id}} |
conn_mod_def::GJ56pTCXRaY::gJyae3GJTUOm9xU0EUziJA |
| List Messages |
GET |
/v1/messages |
conn_mod_def::GJ56pUpvFag::k7EKMu7ASMuJiH-FwF65vw |
| Send a Text Message |
POST |
/v1/messages |
conn_mod_def::GJ56pfWH9t4::GhmE60QEQGa7biRqmLN2CQ |
Calls
| Action |
Method |
Path |
Action id |
| Get a Call by ID |
GET |
/v1/calls/{{callId}} |
conn_mod_def::GJ56pBh_BYI::-2pBOLgbQT2O8ZvVsLkm3g |
| List Calls |
GET |
/v1/calls |
conn_mod_def::GJ56pLYyx9E::IM5VE_87RtiY5oOrNgniBA |
Users
| Action |
Method |
Path |
Action id |
| Get a User by ID |
GET |
/v1/users/{{userId}} |
conn_mod_def::GJ56pdwCqJ0::VC7a-QPQRuSAW8MdwqbY1w |
| List Users |
GET |
/users |
conn_mod_def::GJ56pdlrV5o::c9DkKg4WR-KJ6s5y3wbrvg |
PhoneNumbers
| Action |
Method |
Path |
Action id |
| Get a Phone Number by ID |
GET |
/v1/phone-numbers/{{phoneNumberId}} |
conn_mod_def::GJ56pdoeVic::jIYFXsb-SPO5PYqXnQqgQQ |
| List Phone Numbers (Workspace) |
GET |
/v1/phone-numbers |
conn_mod_def::GJ56pfSUSJc::2FZABVYbTYq4sh1byFE2FQ |
CallSummaries
| Action |
Method |
Path |
Action id |
| Get a Call Summary |
GET |
/v1/call-summaries/{{callId}} |
conn_mod_def::GJ56pBK1PYk::cX_1hN-YQiGDQF2OHKv7iA |
CallVoicemails
| Action |
Method |
Path |
Action id |
| Get a Call’s Voicemail |
GET |
/call-voicemails/{{callId}} |
conn_mod_def::GJ56pB4GKKc::ovpZsbOBRgWw8ldJFbhGHA |
Conversations
| Action |
Method |
Path |
Action id |
| List Conversations |
GET |
/v1/conversations |
conn_mod_def::GJ56pV_xUUU::Hr7Wgn5QRvaEsCr2dYxWHA |
CallWebhooks
| Action |
Method |
Path |
Action id |
| Create a Call Webhook |
POST |
/v1/webhooks/calls |
conn_mod_def::GJ56pmpEQVU::Vk6UqHyYSqSmJDSxXvp6DQ |
CallTranscriptWebhooks
| Action |
Method |
Path |
Action id |
| Create a Call Transcript Webhook |
POST |
/v1/webhooks/call-transcripts |
conn_mod_def::GJ56pnAIwBM::sl6mvC8ZQESAbXla-jacmA |
WebhooksMessages
| Action |
Method |
Path |
Action id |
| Create a Messages Webhook |
POST |
/v1/webhooks/messages |
conn_mod_def::GJ56pnMvb3U::bg-OcGAwSg2-b2GpMx8oIA |
CallRecordings
| Action |
Method |
Path |
Action id |
| List a Call’s Recordings |
GET |
/v1/call-recordings/{{callId}} |
conn_mod_def::GJ56pBhF5MY::_dcneQFvRsKaANvb9UrFVQ |
CallTranscripts
| Action |
Method |
Path |
Action id |
| Get a Call Transcript |
GET |
/v1/call-transcripts/{{id}} |
conn_mod_def::GJ56pBvOWTY::AwOjZZN_S5ye7hamAouqmA |
ContactCustomFields
| Action |
Method |
Path |
Action id |
| List Contact Custom Fields |
GET |
/v1/contact-custom-fields |
conn_mod_def::GJ56pIlFmjU::yHDMQI-cTlOFeBs-yFCPpg |
When a call fails
The error comes from OpenPhone, not from One. A 400 or 422 means your parameters do not match the schema, so re-read the knowledge and fix the field. A 401 or 403 means the connection needs re-authorizing, which no retry will fix. A 404 means the id is not on this account. A 429 means slow down. Never retry a write more than once: the first attempt may have landed.
Full catalog: https://www.withone.ai/knowledge/open-phone
Integration knowledge by One (withone.ai), licensed under One-Knowledge-1.0. Attribution must be preserved in derivative works.
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