---
title: "Changes to Create a new Cosigner"
method: POST
path: "/v0/platform/cosigners"
---

# Changes to Create a new Cosigner

`POST /v0/platform/cosigners`

> Every recorded change to this endpoint, newest first.
> 95 revisions in range; 1 not diffed.

## Timeline

Changed in 4 of 95 revisions.

- **2026-07-23** `6941029c0ca9` — 25 breaking, 37 info
- **2026-06-16** `187d6a5259c6` — 1 info
- **2026-06-08** `03ea93e2f608` — 39 breaking, 17 warning, 31 info
- **2026-05-04** `7edcbad717e5` — 2 info

## Changes

- **2026-07-23** `6941029c0ca9` — 25 breaking, 37 info
  - removed the enum value `advanced_control_policy` of the request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy`
  - removed the enum value `advanced_control_policy` of the request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy`
  - removed the enum value `advanced_control_policy` of the request property `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy`
  - removed the enum value `advanced_control_policy` of the request property `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy`
  - removed the enum value `advanced_control_policy` of the request property `data/oneOf[subschema #5: CosignerSquadsDataExternal]/security_policy`
  - removed the enum value `blockaid_ootb_policy` of the request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy`
  - removed the enum value `blockaid_ootb_policy` of the request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy`
  - removed the enum value `blockaid_ootb_policy` of the request property `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy`
  - removed the enum value `blockaid_ootb_policy` of the request property `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy`
  - removed the enum value `blockaid_ootb_policy` of the request property `data/oneOf[subschema #5: CosignerSquadsDataExternal]/security_policy`
  - the `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy` request property type changed from `string` to no type
  - the `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy` request property type changed from `string` to no type
  - the `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy` request property type changed from `string` to no type
  - the `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy` request property type changed from `string` to no type
  - the `data/oneOf[subschema #5: CosignerSquadsDataExternal]/security_policy` request property type changed from `string` to no type
  - the response property `data/oneOf[subschema #1: FireblocksCosignerResponseExternal]/security_policy` became optional for the status `201`
  - the response property `data/oneOf[subschema #2: FordefiCosignerResponseExternal]/security_policy` became optional for the status `201`
  - the response property `data/oneOf[subschema #3: CosignerSafeResponseExternal]/security_policy` became optional for the status `201`
  - the response property `data/oneOf[subschema #4: CosignerSquadsResponseExternal]/security_policy` became optional for the status `201`
  - the response property `data/oneOf[subschema #5: UtilaCosignerResponseExternal]/security_policy` became optional for the status `201`
  - the `data/oneOf[subschema #1: FireblocksCosignerResponseExternal]/security_policy` response's property type changed from `string` to no type for status `201`
  - the `data/oneOf[subschema #2: FordefiCosignerResponseExternal]/security_policy` response's property type changed from `string` to no type for status `201`
  - the `data/oneOf[subschema #3: CosignerSafeResponseExternal]/security_policy` response's property type changed from `string` to no type for status `201`
  - the `data/oneOf[subschema #4: CosignerSquadsResponseExternal]/security_policy` response's property type changed from `string` to no type for status `201`
  - the `data/oneOf[subschema #5: UtilaCosignerResponseExternal]/security_policy` response's property type changed from `string` to no type for status `201`
  - added the new optional request property `fallback_behavior`
  - added `#/components/schemas/ExternalPolicyOption, subschema #2` to the `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy` request property `anyOf` list
  - added `#/components/schemas/ExternalPolicyOption, subschema #2` to the `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy` request property `anyOf` list
  - added `#/components/schemas/ExternalPolicyOption, subschema #2` to the `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy` request property `anyOf` list
  - added `#/components/schemas/ExternalPolicyOption, subschema #2` to the `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy` request property `anyOf` list
  - added `#/components/schemas/ExternalPolicyOption, subschema #2` to the `data/oneOf[subschema #5: CosignerSquadsDataExternal]/security_policy` request property `anyOf` list
  - the request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy` became optional
  - the request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy` became optional
  - the request property `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy` became optional
  - the request property `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy` became optional
  - the request property `data/oneOf[subschema #5: CosignerSquadsDataExternal]/security_policy` became optional
  - request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy` deprecated
  - request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy` deprecated
  - request property `data/oneOf[subschema #3: UtilaCosignerDataExternal]/security_policy` deprecated
  - request property `data/oneOf[subschema #4: CosignerSafeDataExternal]/security_policy` deprecated
  - …22 more
- **2026-06-16** `187d6a5259c6` — 1 info
  - the endpoint scheme security `JWT` was added to the API
- **2026-06-08** `03ea93e2f608` — 39 breaking, 17 warning, 31 info
  - added the new required request property `approval_actions/items/oneOf[subschema #2: SlackExternalAction]/channels`
  - added the new required request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/involvement_level`
  - added the new required request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/security_policy`
  - added the new required request property `data/oneOf[subschema #1: FireblocksCosignerDataExternal]/unsupported_chain_behavior`
  - added the new required request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/involvement_level`
  - added the new required request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/security_policy`
  - added the new required request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/unsupported_chain_behavior`
  - added the new required request property `data/oneOf[subschema #3: CosignerSafeDataExternal -> subschema #4: CosignerSafeDataExternal]/involvement_level`
  - added the new required request property `data/oneOf[subschema #3: CosignerSafeDataExternal -> subschema #4: CosignerSafeDataExternal]/security_policy`
  - added the new required request property `data/oneOf[subschema #3: CosignerSafeDataExternal -> subschema #4: CosignerSafeDataExternal]/wallet_address`
  - added the new required request property `data/oneOf[subschema #4: CosignerSquadsDataExternal -> subschema #5: CosignerSquadsDataExternal]/involvement_level`
  - added the new required request property `data/oneOf[subschema #4: CosignerSquadsDataExternal -> subschema #5: CosignerSquadsDataExternal]/security_policy`
  - added the new required request property `data/oneOf[subschema #4: CosignerSquadsDataExternal -> subschema #5: CosignerSquadsDataExternal]/wallet_address`
  - added the new required request property `malicious_actions/anyOf[subschema #1]/items/oneOf[subschema #2: SlackExternalAction]/channels`
  - added the new required request property `proposal_actions/items/oneOf[subschema #2: SlackExternalAction]/channels`
  - added the new required request property `rejection_actions/items/oneOf[subschema #2: SlackExternalAction]/channels`
  - the request property `data/oneOf[subschema #3: CosignerSafeDataExternal -> subschema #4: CosignerSafeDataExternal]/override_address` became required
  - removed the enum value `all_workspace` of the request property `data/oneOf[subschema #2: FordefiCosignerDataExternal]/scope`
  - response property `updated_by` list-of-types was widened by adding types `null` to media type `application/json` of response `201`
  - removed the required property `added_by` from the response with the `201` status
  - removed the required property `approval_actions/items/oneOf[subschema #2: SlackExternalAction]/channel_ids` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #1: FireblocksCosignerResponseExternal]/security_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #1: FireblocksCosignerResponseExternal]/signing_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #1: FireblocksCosignerResponseExternal]/unsupported_chains_fallback_policy` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #2: FordefiCosignerResponseExternal]/security_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #2: FordefiCosignerResponseExternal]/signing_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #2: FordefiCosignerResponseExternal]/unsupported_chains_fallback_policy` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #3: CosignerSafeResponseExternal]/safe_address` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #3: CosignerSafeResponseExternal]/security_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #3: CosignerSafeResponseExternal]/signing_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #4: CosignerSquadsResponseExternal]/security_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #4: CosignerSquadsResponseExternal]/signing_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #4: CosignerSquadsResponseExternal]/squads_address` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #5: UtilaCosignerResponseExternal]/security_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #5: UtilaCosignerResponseExternal]/signing_mode` from the response with the `201` status
  - removed the required property `data/oneOf[subschema #5: UtilaCosignerResponseExternal]/unsupported_chains_fallback_policy` from the response with the `201` status
  - removed the required property `malicious_actions/anyOf[subschema #1]/items/oneOf[subschema #2: SlackExternalAction]/channel_ids` from the response with the `201` status
  - removed the required property `proposal_actions/items/oneOf[subschema #2: SlackExternalAction]/channel_ids` from the response with the `201` status
  - removed the required property `rejection_actions/items/oneOf[subschema #2: SlackExternalAction]/channel_ids` from the response with the `201` status
  - removed the request property `approval_actions/items/oneOf[subschema #2: SlackExternalAction]/channel_ids`
  - …47 more
- **2026-05-04** `7edcbad717e5` — 2 info
  - added the new optional request property `malicious_actions`
  - added the optional property `malicious_actions` to the response with the `201` status

---

[Operation](https://skmtc.dev/blockaid-official/apis/blockaid-api/docs/v0/platform/cosigners/post.md) · [API](https://skmtc.dev/blockaid-official/apis/blockaid-api.md) · [Page](https://skmtc.dev/blockaid-official/apis/blockaid-api/changes/v0/platform/cosigners/post)