> ## Documentation Index > Fetch the complete documentation index at: https://docs.runners.family/llms.txt > Use this file to discover all available pages before exploring further. # Get the launchpad signature for a self-built pool transaction > Only for pool transactions built without `buildTransactions` (server-built ones arrive tagged). RUNNERS signs only a pool transaction that matches the prepared draft byte for byte, before the creator signs. ## OpenAPI ````yaml /openapi.json post /api/launch/tag openapi: 3.1.0 info: title: RUNNERS Launch API version: 1.3.0 summary: Launch a Solana coin from an agent or bot. description: >- Upload coin metadata, estimate launch costs, prepare unsigned launch transactions, sign locally, submit and confirm. All amounts use integer base-unit strings. No website session or integrator API key is required. See the Launch a coin guide for the optional authorization messages and the launchpad signer. servers: - url: https://runners.family description: RUNNERS production API (Solana mainnet) security: [] tags: - name: Launch description: >- Launch a coin from any HTTP client with an ed25519 keypair: upload the image and details, prepare (one transaction when a shared config exists for the quote token's price band, otherwise two), sign with the listed signers, submit (optionally relayed) and confirm. The launch transactions the creator's wallet signs authorize the coin; wallet message signatures for the upload and the preparation are optional. See the Launch a coin guide. paths: /api/launch/tag: post: tags: - Launch summary: Get the launchpad signature for a self-built pool transaction description: >- Only for pool transactions built without `buildTransactions` (server-built ones arrive tagged). RUNNERS signs only a pool transaction that matches the prepared draft byte for byte, before the creator signs. operationId: tagLaunchTransaction requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/LaunchTagRequest' responses: '200': description: The launchpad's signature. content: application/json: schema: $ref: '#/components/schemas/LaunchTag' '403': description: '`origin_forbidden`.' content: application/json: schema: $ref: '#/components/schemas/LaunchError' '404': description: >- `draft_not_found` (no prepared, unsubmitted draft) or `not_found` (tagging unavailable). content: application/json: schema: $ref: '#/components/schemas/LaunchError' '422': description: >- `transaction_invalid` or `transaction_mismatch` (the wire differs from the prepared draft or lacks the launchpad signer). content: application/json: schema: $ref: '#/components/schemas/LaunchError' '429': $ref: '#/components/responses/RateLimited' '503': description: '`metadata_required` or `unavailable`.' content: application/json: schema: $ref: '#/components/schemas/LaunchError' components: schemas: LaunchTagRequest: type: object required: - deploymentId - baseMint - owner - transactionBase64 description: >- A self-built pool transaction for a prepared draft, with the launchpad signer added as a read-only signer after the creator and mint. The mint may have signed; the creator signs after the tag. properties: deploymentId: type: string baseMint: $ref: '#/components/schemas/Address' owner: $ref: '#/components/schemas/Address' transactionBase64: type: string contentEncoding: base64 LaunchTag: type: object required: - signer - signatureBase64 properties: signer: $ref: '#/components/schemas/Address' description: The RUNNERS launchpad signer. signatureBase64: type: string description: >- The launchpad's ed25519 signature for the submitted message; add it to the transaction. LaunchError: type: object required: - error - code properties: error: type: string code: type: string enum: - request_invalid - signature_invalid - authorization_expired - origin_forbidden - network_changed - unavailable - metadata_required - draft_changed - draft_not_found - draft_not_ready - already_submitted - not_retryable - upload_limit - price_unavailable - quote_unpriced - quote_illiquid - price_pending - price_changed - estimate_expired - estimate_changed - unsupported_quote - standard_pair_sol - transfer_fee_quote_unsupported - first_buy_too_large - first_buy_invalid - transaction_invalid - transaction_mismatch - transaction_expired - not_found - conflict - request_too_large - image_invalid - rate_limited - insufficient_funds - config_required - unsent_limit Address: type: string pattern: ^[1-9A-HJ-NP-Za-km-z]{32,44}$ description: Base58 Solana address. examples: - So11111111111111111111111111111111111111112 Error: type: object required: - error properties: code: type: string description: >- Stable machine-readable code. Always present on /api/v1 routes and 429 responses. enum: - request_invalid - request_too_large - origin_forbidden - not_found - method_not_allowed - rate_limited - unavailable error: type: string description: Plain-language explanation. responses: RateLimited: description: Too many requests in this route class. Wait `Retry-After` seconds. headers: Retry-After: $ref: '#/components/headers/Retry-After' RateLimit-Limit: $ref: '#/components/headers/RateLimit-Limit' RateLimit-Remaining: $ref: '#/components/headers/RateLimit-Remaining' RateLimit-Reset: $ref: '#/components/headers/RateLimit-Reset' RateLimit-Policy: $ref: '#/components/headers/RateLimit-Policy' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: rate_limited error: Too many requests. Please wait a moment and try again. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer RateLimit-Limit: description: Requests the client may make at once in this route class (bucket size). schema: type: integer RateLimit-Remaining: description: Requests available now. schema: type: integer RateLimit-Reset: description: Seconds until the bucket is full again. schema: type: integer RateLimit-Policy: description: >- `;w=;burst=`: the sustained rate and the bucket size. schema: type: string example: 600;w=60;burst=120 ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.