> ## Documentation Index > Fetch the complete documentation index at: https://docs.outerlayer.ai/llms.txt > Use this file to discover all available pages before exploring further. # Read a runner key's host binding > Returns whether the calling runner key is bound to a host key, and the bound key's fingerprint and binding time. A bound key's request must be signed by its host key like any other, so a host the key is not bound to gets `runner_key_signature_invalid` instead of this answer. ## OpenAPI ````yaml /openapi.yaml get /v1/runner/host-key openapi: 3.0.3 info: contact: email: hello@outerlayer.ai url: https://www.outerlayer.ai description: >- The OuterLayer Gateway API lets you ingest coding-agent sessions and record evidence of work programmatically. Most teams reach it through the `outerlayer` CLI, which calls it for them. Call it directly to build your own integration or to automate what the dashboard does. Versioning: every endpoint is prefixed with `/v1/`. Breaking changes ship under a new version prefix (`/v2/`, etc.) with a 90-day-minimum deprecation window; anything additive lands on the current prefix. Vocabulary: the dashboard calls this API's `app` a **factory** — the unit that owns a set of repositories, the agent sessions worked on them, and the evidence they produce. They are the same entity. The API keeps `app` in its paths, headers, and field names because those are a published contract; only the product surface was renamed. title: OuterLayer Gateway API version: '1.0' servers: - description: Production (OuterLayer Cloud) url: https://api.outerlayer.ai - description: Local dev server (self-hosted gateway) url: http://localhost:9418 security: - AppId: [] BearerAuth: [] tags: - description: >- What a CLI login token can read about its owner without naming a factory, such as the factories they can use. name: Account - description: >- Coding-agent session ingest (outerlayer sync) and content-addressed session images. name: Agents - description: >- Evidence artifacts (screenshots, recordings, reports, logs) emitted as proof of a change and anchored to pull requests. name: Artifacts - description: >- Pass/fail outcomes of checks run in your own CI or compute, anchored to pull requests with the run URL as proof. name: Emitted Results - description: >- The acceptance criteria of a work item, recorded as one list. The Criteria tab, its count and the item status read that list. name: Criteria - description: >- What any agent found wrong about a change under review or about a rule it ran on, recorded on a work item. name: Findings - description: >- Add or remove a source's statement that it is working on an issue or pull request, and read what is currently live. name: Work Items - description: >- What the factory's GitHub App installation lets builds do on each connected repository, and whether each default branch requires a pull request. name: Repositories - description: >- A runner host's heartbeat — its CLI version, slots and last request for work — and the factory's list of hosts with a derived status. name: Hosts - description: Query server feature availability. name: Capabilities - description: Per-model LLM pricing data. Public, unauthenticated. name: Pricing - description: >- Create, list, and revoke factory API keys. Plaintext returned exactly once at creation. name: API Keys - description: >- Factory CRUD — a factory is owned by an organization and is the unit every other resource hangs off. Lets a headless agent provision one without the dashboard. name: Apps - description: >- Agent-coding session list and full transcript reads, with actor-privacy controls for machine keys. name: Sessions - description: >- Per-model token spend and fleet-wide agent behavior tiles, including two-window comparisons. name: Metrics - description: Synced-commit history of the app's `.outerlayer/` context tree. name: Context - description: >- Session→PR attribution: which agent sessions produced which pull requests, and what each attributed PR cost. name: PRs - description: Service health checks. name: Health - description: >- Org member and role administration, authenticated with an org-scoped management API key (`olk_…`) minted in the dashboard's settings. name: Org Management - description: OAuth 2.1 discovery metadata for MCP connector clients. name: OAuth paths: /v1/runner/host-key: get: tags: - Work Items summary: Read a runner key's host binding description: >- Returns whether the calling runner key is bound to a host key, and the bound key's fingerprint and binding time. A bound key's request must be signed by its host key like any other, so a host the key is not bound to gets `runner_key_signature_invalid` instead of this answer. operationId: get-runner-host-key parameters: - description: >- HTTP Message Signature (RFC 9421) made with the runner key's host key: `runner=::`. in: header name: Signature required: false schema: description: >- HTTP Message Signature (RFC 9421) made with the runner key's host key: `runner=::`. type: string - description: >- The signature's covered components and parameters: `runner=("@method" "@path" "@query" "content-digest");created=;nonce="";keyid="";alg="ed25519"`. in: header name: Signature-Input required: false schema: description: >- The signature's covered components and parameters: `runner=("@method" "@path" "@query" "content-digest");created=;nonce="";keyid="";alg="ed25519"`. type: string - description: >- RFC 9530 digest of the request body, always sent, including for a request with none: `sha-256=::`. in: header name: Content-Digest required: false schema: description: >- RFC 9530 digest of the request body, always sent, including for a request with none: `sha-256=::`. type: string responses: '200': content: application/json: schema: properties: data: properties: bound: type: boolean boundAt: format: date-time nullable: true type: string fingerprint: nullable: true type: string required: - bound - fingerprint - boundAt type: object required: - data type: object description: 'The binding, or `bound: false` for a key that has none.' '400': content: application/json: schema: properties: error: properties: code: type: string message: type: string required: - code - message type: object required: - error type: object description: Invalid request parameters (validation failed). '401': content: application/json: schema: properties: error: properties: code: type: string message: type: string required: - code - message type: object required: - error type: object description: >- Missing or invalid API key, or a runner key's signature was refused: `runner_key_signature_required` (the request carries no signature), `runner_key_signature_invalid` (it does not verify against the host key the key is bound to, or the body does not match its digest), `runner_key_signature_stale` (`created` is more than five minutes from the gateway's clock) or `runner_key_signature_replayed` (the nonce was accepted in the last five minutes). '403': content: application/json: schema: properties: error: properties: code: type: string message: type: string required: - code - message type: object required: - error type: object description: Caller lacks 'work.claim' permission. components: securitySchemes: AppId: description: Factory id the request is scoped to. in: header name: X-Outerlayer-App-Id type: apiKey BearerAuth: description: API key (sk_outerlayer_*) scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.