feat(cards): add a platform per-transaction spending cap

[DhruvPareek]

Reason

Platforms need one reversible control that caps every Grid-decided card transaction without destroying stricter per-card settings.

Overview

Adds maxCardSpendPerTransaction to platform config responses and PATCH /config. A positive int64 sets the platform cap, omission preserves it, and null clears it. Grid enforces the lower of this cap and each card-specific maxSpendPerTransaction; the contract states that the cap applies immediately to existing and future cards while provider-decided card programs remain unaffected.

Updates card create, update, and response documentation to distinguish the stored card-specific cap from the effective enforced limit. This PR defines the source OpenAPI contract only; generated Webdev artifacts and server implementation follow in separate Webdev PRs.

Test Plan

• make build
• make lint — passed with the repository existing warning set and no errors

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[DhruvPareek]

• feat(cards): add a platform per-transaction spending cap #865 👈 (View in Graphite)
• main

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[github-actions]

✱ Stainless preview builds for grid

This PR will update the grid SDKs with the following commit messages.

cli

feat(api): add max_card_spend_per_transaction parameter to config update

go

feat(api): add maxCardSpendPerTransaction to config

kotlin

feat(api): add maxCardSpendPerTransaction field to platform config

openapi

feat(api): add maxCardSpendPerTransaction field to platform configuration

php

feat(api): add maxCardSpendPerTransaction parameter to config

python

feat(api): add max_card_spend_per_transaction to config

ruby

feat(api): add max_card_spend_per_transaction to platform config

typescript

feat(api): add maxCardSpendPerTransaction to platform config

Edit this comment to update them. They will appear in their respective SDK's changelogs.

✅ grid-typescript studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ✅ → lint ❗ → test ✅

npm install https://pkg.stainless.com/s/grid-typescript/38fd35e4f3995465bbdaa7abdde03bd933dc0048/dist.tar.gz

✅ grid-openapi studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️

✅ grid-ruby studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ✅ → lint ✅ → test ✅

✅ grid-go studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ✅ → lint ❗ → test ❗

go get github.com/stainless-sdks/grid-go@d463781c7b06fa4abac04e23d03cceaaa402e41c

✅ grid-kotlin studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ✅ → lint ✅ → test ❗

✅ grid-python studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ✅ → lint ❗ → test ❗

pip install https://pkg.stainless.com/s/grid-python/a2034e7af32869d7ce7be35998a680fe931c2670/grid-0.0.1-py3-none-any.whl

✅ grid-php studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → lint ✅ → test ✅

✅ grid-cli studio · code · diff

Your SDK build had at least one "warning" diagnostic, but this did not represent a regression.
generate ⚠️ → build ❗ → lint ❗ → test ❗

---

This comment is auto-generated by GitHub Actions and is automatically kept up to date as you push.
If you push custom code to the preview branch, re-run this workflow to update the comment.
Last updated: 2026-08-25 21:38:49 UTC

[greptile-apps]

Greptile Summary

Adds an optional, nullable platform-wide per-transaction card spending cap to the platform configuration contract and documents that Grid enforces the lower of the platform and card-specific caps.

• Defines positive-int64 set, omission-preserves, and null-clears semantics for PATCH /config.
• Clarifies that card responses retain the configured card-specific cap rather than reporting the effective cap.
• Applies the platform cap to existing and future Grid-decided cards while excluding provider-decided programs.
• Rebuilds both checked-in OpenAPI bundles from the modular source.

Confidence Score: 5/5

The contract change appears safe to merge, with no concrete blocking or independently actionable non-blocking defect identified.

The new field follows the established nullable int64 pattern, preserves omission-versus-null semantics in the contract, consistently distinguishes stored and effective card limits, and appears in both generated bundles.

Important Files Changed

Filename	Overview
openapi/components/schemas/config/PlatformConfig.yaml	Adds the nullable platform-level card cap to configuration responses with its scope and immediate-effect semantics.
openapi/components/schemas/config/PlatformConfigUpdateRequest.yaml	Adds consistent tri-state update semantics using the repository’s established nullable-int64 schema pattern.
openapi/components/schemas/cards/Card.yaml	Clarifies that the returned card field is the stored card-specific cap and not the lower effective limit.
openapi/paths/platform/config.yaml	Documents the new PATCH behavior and includes the cap in the request example.
openapi/paths/cards/cards.yaml	Updates card issuance documentation to explain interaction between card and platform caps.
openapi/paths/cards/cards_{id}.yaml	Updates card modification documentation while preserving existing set, clear, and closed-card constraints.
openapi.yaml	Generated root bundle is aligned with the modular OpenAPI source.
mintlify/openapi.yaml	Generated Mintlify contract is aligned with the modular OpenAPI source.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    P[Platform maxCardSpendPerTransaction] --> E{Both caps configured?}
    C[Card maxSpendPerTransaction] --> E
    E -->|Yes| L[Effective limit = lower value]
    E -->|Platform only| P1[Effective limit = platform cap]
    E -->|Card only| C1[Effective limit = card cap]
    E -->|Neither| N[No Grid per-transaction cap]
    G{Who decides authorization?} -->|Grid| E
    G -->|Provider| U[Platform cap does not apply]

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