Comparison / storage, delivery, and provisioning
Best way to store API keys for AI agents
The best API key store is the one that matches the agent's execution boundary. Compare password managers, infrastructure vaults, developer secret platforms, cloud secret managers, and website-provisioning brokers by how they deliver and control the key.
Short answer
For local, user-approved coding work, a password manager with runtime injection can be the simplest safe choice. For production workloads, use cloud workload identity where possible, otherwise use a cloud secret manager or infrastructure vault with narrow machine identity and rotation. For developer environments and CI, Infisical or Doppler can centralize project secrets and runtime delivery. When the account or key does not exist yet, add a provisioning layer such as Trusty Squire.
Avoid selecting on storage alone. The important path is create, store, authorize, deliver, use, log, rotate, and revoke. A key can be encrypted at rest and still leak through an MCP response, shell output, process environment, browser page, trace, or committed file.
Scope comparison
| Option | Primary scope | Agent delivery | Best fit | Important limit |
|---|---|---|---|---|
| Trusty Squire | Website account and API-key provisioning plus constrained credential use. | Reference-based tools, provider operations, and scoped runtime grants. | The agent needs a credential that has not been created yet. | Not a replacement for every enterprise PKI, dynamic-secret, or cloud-native identity feature. |
| 1Password | Human and team passwords plus developer secrets in Environments. | Approved runtime injection for Codex through Environments MCP Server. | Existing 1Password teams and user-approved local agent workflows. | General provider signup is outside the cited MCP scope; Agentic Autofill fills existing Login items. |
| HashiCorp Vault | Infrastructure secrets, dynamic credentials, PKI, encryption, policy, and leases. | Agent or Proxy delivery, API clients, or beta MCP operations. | Organizations operating a dedicated infrastructure security control plane. | Operational complexity is real, and some MCP tools can expose secret values. |
| Infisical | Application secret management, synchronization, dynamic secrets, and MCP governance. | CLI or SDK delivery; Agent Sentinel governs MCP traffic separately. | Developer platforms, CI, application fleets, and teams needing MCP controls. | Its public docs MCP is not a secret-reading MCP, and website signup is a separate job. |
| Doppler | Project, config, and environment based developer secret management. | CLI, SDK, service tokens, or an experimental operational MCP server. | Teams that want a focused developer-secrets workflow. | Authorized clients or processes can receive values; MCP status is experimental. |
| AWS Secrets Manager | AWS-native secret storage, retrieval, rotation, resource policy, and replication. | AWS SDK or runtime integrations under IAM; AgentCore Gateway can centralize MCP credentials separately. | AWS workloads with strong IAM and service integration requirements. | AWS Secrets Manager itself is not a general website signup or agent browser tool. |
Cloud workload identity can remove some long-lived API keys entirely and should be preferred where the target service supports it. The products above remain relevant for third-party or legacy credentials.
How to choose
Choose the delivery boundary first
A local coding agent, CI runner, hosted agent, and production service should not share one delivery pattern by default. A local workflow may use explicit human approval. CI needs a non-interactive machine identity and narrow project scope. Production needs short-lived identity where possible, rotation, reliable retrieval, and audited failure behavior.
Write down whether the target process needs the value or merely needs one authenticated operation. If it only needs the operation, a broker or signed request can reduce exposure. If it needs the value, inject it into the narrowest process at runtime and keep it out of prompts, command arguments, logs, and repository files.
Storage does not solve creation
Secret managers generally assume a credential already exists, can be generated by a supported engine, or can be synchronized from another system. Third-party SaaS often requires a website account, email verification, plan selection, and dashboard configuration before a key exists.
Trusty Squire covers that provider-facing workflow. It can complement 1Password, Vault, Infisical, Doppler, or AWS rather than replace their broader storage and governance capabilities. The handoff needs one authoritative owner and a rotation plan.
Use a minimum safety baseline
Whichever product you choose, scope the provider key itself, scope the identity that can retrieve or use it, and redact outputs at every boundary. Test revocation and rotation before an incident. Inventory browser captures, traces, build logs, and crash reports as possible secret stores too.
- Prefer workload identity or short-lived credentials over long-lived API keys.
- Keep reusable values out of prompts and normal MCP responses.
- Separate provisioning authority from everyday use when possible.
- Assign one system of record and one rotation owner for every credential.
Decision
Use 1Password for approved local use of existing team secrets, Vault for a dedicated infrastructure secret control plane, Infisical or Doppler for developer secret workflows, and AWS Secrets Manager for AWS-native applications. Add Trusty Squire when the agent must first create the third-party account or API key. Prefer identity over stored keys wherever the provider supports it.
Product scope checked against the official sources below on .
Frequently asked questions
- What is the safest way to give an AI agent an API key?
- Do not paste it into the prompt. Prefer a scoped tool that performs the needed operation or injects the key into a narrow runtime after authorization. Use a short-lived identity instead of a reusable key when available.
- Is a password manager enough for production agents?
- It can be appropriate for some workflows, but production often needs machine identity, non-interactive retrieval, rotation, availability guarantees, and platform-native audit controls. Choose against those requirements rather than the storage interface alone.
- Are environment variables safe for API keys?
- Runtime injection into a narrow process is safer than committing a file, but the process and its children can still read the value. Environment dumps, crash reports, and debug output also need controls.
- Which secret manager can create the provider account too?
- Trusty Squire is designed to operate the provider website, handle human handoffs, create the key, and capture it. Traditional secret managers focus on storage, generation through supported engines, delivery, and governance.
Official sources
These links support the current product-scope claims. Features and release status can change, so verify them again before a security or procurement decision.