feat: add Sardis payment action provider

[EfeDurmaz16]

Summary

• Adds a new Sardis action provider enabling AI agents to make policy-controlled financial transactions
• 5 actions: sardis_pay, sardis_check_balance, sardis_check_policy, sardis_set_policy, sardis_list_transactions
• Supports EVM chains: Base, Polygon, Ethereum, Arbitrum, Optimism
• Stablecoins: USDC, USDT, PYUSD, EURC
• Uses raw HTTP calls to Sardis API (no external package dependency beyond requests)
• Follows env var pattern (SARDIS_API_KEY, SARDIS_WALLET_ID) consistent with Twitter/SSH providers

What is Sardis?

Sardis is the Payment OS for the Agent Economy — infrastructure enabling AI agents to make real financial transactions safely through non-custodial MPC wallets with natural language spending policies.

Key features:

• Policy-controlled payments: Natural language spending rules (e.g. "Max $50/tx, daily limit $500")
• Non-custodial: MPC wallets — Sardis never holds private keys
• Multi-chain: Base, Polygon, Ethereum, Arbitrum, Optimism
• Audit trail: Append-only ledger for all transactions

Files

File	Purpose
action_providers/sardis/__init__.py	Package exports
action_providers/sardis/sardis_action_provider.py	Main provider with 5 @create_action methods
action_providers/sardis/schemas.py	Pydantic input schemas
action_providers/sardis/constants.py	API URL, supported chains/tokens
action_providers/sardis/README.md	Documentation
tests/action_providers/sardis/	21 tests (init, schemas, actions, network support)
changelog.d/add-sardis-action-provider.feature.md	Changelog entry

Test plan

• All 21 unit tests pass (pytest tests/action_providers/sardis/ -v)
• Ruff linting clean
• Provider registered in __init__.py exports
• CI pipeline passes

🤖 Generated with Claude Code

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2

[EfeDurmaz16]

Small maintenance update while this PR was stale:

• merged current origin/main into the branch and resolved the Python action provider export conflict
• kept the Sardis provider exports intact against the current sorted __all__ layout
• hardened the Sardis action schemas with bounded recipient/purpose/policy inputs and decimal amount validation
• stopped returning raw non-JSON HTTP response bodies from Sardis API errors, so server response text cannot leak back into agent output
• added regression coverage for invalid amounts, bounded free-form fields, list limit validation, and non-JSON HTTP error bodies

Local verification:

• uv run pytest tests/action_providers/sardis -q -> 26 passed
• uv run ruff check coinbase_agentkit/action_providers/sardis tests/action_providers/sardis
• uv run ruff format --check coinbase_agentkit/action_providers/sardis tests/action_providers/sardis
• git diff --check

The PR is mergeable again from GitHub’s mergeability check. Heimdall still shows additional review required.