> ## Documentation Index > Fetch the complete documentation index at: https://docs.firedrill.run/llms.txt > Use this file to discover all available pages before exploring further. # Open one Tool app in a ready environment > Issues short-lived access to one package's isolated browser app using the same environment data. Requires drill.run and the observed ready runtime version and generation. No control or ordinary world bearer is returned. The credential is in the URL fragment; do not log or persist this response. Opening an app does not run your agent or wake compute. After reset or expiry, obtain a fresh link explicitly; never resend an uncertain Tool action. Responses are private and non-cacheable. ## OpenAPI ````yaml /api-reference/openapi.json post /v1/projects/{projectId}/environments/{environmentId}/tool-apps openapi: 3.1.0 info: title: Firedrill Control API version: 1.0.0 description: >- The control plane for drills, drill runs, and the worlds they run in. Errors always carry the canonical envelope; unsafe operations require an Idempotency-Key; long work returns an operation resource. servers: - url: https://api.firedrill.run security: - controlCredential: [] paths: /v1/projects/{projectId}/environments/{environmentId}/tool-apps: post: summary: Open one Tool app in a ready environment description: >- Issues short-lived access to one package's isolated browser app using the same environment data. Requires drill.run and the observed ready runtime version and generation. No control or ordinary world bearer is returned. The credential is in the URL fragment; do not log or persist this response. Opening an app does not run your agent or wake compute. After reset or expiry, obtain a fresh link explicitly; never resend an uncertain Tool action. Responses are private and non-cacheable. operationId: environments.openToolApp parameters: - name: projectId in: path required: true schema: type: string pattern: ^prj_[0-9a-z]{12,32}$ - name: environmentId in: path required: true schema: type: string pattern: ^env_[0-9a-z]{12,32}$ - name: Idempotency-Key in: header required: true schema: type: string minLength: 8 maxLength: 128 pattern: ^[A-Za-z0-9._:-]+$ requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/IssueEnvironmentToolAppRequest' responses: '200': description: Scoped isolated Tool app link content: application/json: schema: $ref: '#/components/schemas/HostedToolAppAccess' '400': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '401': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '403': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '404': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '409': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '429': description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' default: description: Canonical error envelope content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' components: schemas: IssueEnvironmentToolAppRequest: type: object properties: actorId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ actorInstanceId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ packageId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ instanceId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ ttlMs: type: integer minimum: 0 exclusiveMinimum: true maximum: 300000 expectedRuntimeVersion: type: integer minimum: -9007199254740991 maximum: 9007199254740991 expectedLeaseGeneration: type: integer minimum: 0 exclusiveMinimum: true maximum: 9007199254740991 required: - actorId - packageId - expectedRuntimeVersion - expectedLeaseGeneration additionalProperties: false HostedToolAppAccess: type: object properties: schemaVersion: type: number enum: - 1 packageId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ instanceId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ actorId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ actorInstanceId: type: string minLength: 1 maxLength: 96 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ sessionId: type: string pattern: ^ses_[0-9a-z]{12,32}$ buildHash: type: string pattern: ^sha256:[0-9a-f]{64}$ url: type: string format: uri expiresAtMs: type: integer minimum: -9007199254740991 maximum: 9007199254740991 replayed: type: boolean required: - schemaVersion - packageId - actorId - sessionId - buildHash - url - expiresAtMs - replayed additionalProperties: false ErrorEnvelope: type: object properties: code: type: string pattern: ^(control|world)\.[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$ message: type: string minLength: 1 correlationId: type: string minLength: 1 retryable: type: boolean retryAfterMs: type: integer exclusiveMinimum: 0 maximum: 9007199254740991 operationId: type: string source: type: string enum: - platform - simulated_provider issues: type: array items: type: object properties: path: type: string code: type: string message: type: string required: - path - code - message additionalProperties: false details: type: object propertyNames: type: string additionalProperties: {} evidence: type: object properties: sessionId: type: string runId: type: string journalSeq: type: integer minimum: 0 maximum: 9007199254740991 buildHash: type: string additionalProperties: false required: - code - message - correlationId - retryable - source additionalProperties: true securitySchemes: controlCredential: type: http scheme: bearer description: Opaque control credential ````