Does Bringing Your Own API Key to Cursor or Claude Code Remove the Provider's Indemnity?

Authentication is not the same as coverage

An API key proves that a request is authorised to reach a model and usually ties usage to an account for billing. It does not describe the legal relationship between the parties. Whether an IP indemnity applies is answered by the agreement the account operates under, the products and plans that agreement names, and the conditions it places on the customer.

Indemnities are typically drafted as conditional promises. A federal procurement clause in 48 CFR Part 52 (NOV 2023 version) illustrates the pattern. The contractor indemnifies the Government against liability for actual or alleged infringement of a US or foreign patent, trademark or copyright arising from contract performance, but only 'provided' that the contractor's stated conditions are met. That clause is not a model provider term. It shows why a question such as 'does BYOK remove the indemnity?' is incomplete. The useful questions are which agreement governs, what it covers, and what the customer must do to remain eligible.

The practical consequence is that two teams using the same tool with the same key could be in different positions if their plans, contract versions or usage differ. Treat BYOK as one fact in the analysis, not the deciding fact.

Usage conditions that can affect a claim

Provider indemnities for generated output commonly depend on customer conduct. Examples worth checking against the actual text include whether outputs were modified, whether the customer knew or should have known an output infringed, whether required safety or filtering features were used, and whether the customer complied with the provider's usage policies. Exclusions and product scope can matter as much as the conditions.

A third-party tool can touch these conditions in ways the enterprise may not notice. It may construct prompts, add context from the repository, post-process responses, apply edits automatically, or change which model handles a request. If a condition refers to modified outputs or required features, the behaviour of the client becomes a contract question, not only a product question.

Legal review should also cover data-use commitments. The FTC has stated that model-as-a-service companies that fail to abide by their privacy commitments to users and customers may be liable under laws it enforces, including commitments not to use customer data to train or update models. Indemnity and data handling are separate topics, but they are usually reviewed together for coding assistants.

Runtime controls and audit-ready evidence

Controls cannot create coverage that a contract does not grant. What they can do is help the enterprise show that its use stayed within the conditions it relies on. That distinction matters for how the program is described to legal and audit teams: the controls generate evidence that supports a position, and counsel decides what that position is.

Enforcement in the execution path means policy is applied to each interaction as it happens, with outcomes of allow, redact or block, rather than reviewed after the fact. For a coding assistant, that can include limiting what context leaves the environment, redacting sensitive content from prompts, and blocking requests or tool calls that policy does not permit. Each decision can be recorded with the policy that produced it.

Code provenance adds a second kind of evidence. Recording the origin, licence and security context of code helps answer whether generated or accepted code carried known licence or security concerns at the time. This is relevant to conditions about knowing infringement and to internal review of what entered the codebase.

Identity is the supporting layer. Agent and tool protocols such as MCP rely on existing identity standards, so tying requests to a developer, a key and a policy decision is achievable with established mechanisms. Retain records against the contract version in force, so the evidence can be read alongside the terms that applied when it was created.

The tradeoff is operational. Enforcement adds a point in the path that must be reliable and tuned, and evidence volumes need retention and residency decisions that match your obligations.

Where Trussed fits

Trussed enforces policy in the execution path across models, agents, tools, MCP servers and coding assistants, with allow, redact, block, rate limit and escalation for human approval, applied to individual interactions and tool calls. It also provides code provenance covering the origin, licence and security context of code, and produces continuous audit-ready evidence from enforcement. It can be deployed self-managed in the customer cloud, with configurable retention and data residency.

This supports an evidence-based position on compliant use for a regulated enterprise. It does not determine whether an indemnity applies, which remains a question for the contracts and for counsel.