> ## Documentation Index > Fetch the complete documentation index at: https://docs.x402layer.cc/llms.txt > Use this file to discover all available pages before exploring further. # Create embeddings > OpenAI-compatible embeddings with input-only billing. Existing text models accept a string or string array. `embeddinggemma-2` also accepts ordered text, image, audio, and video content parts and returns one normalized vector per top-level item. Omitted EG2 `input_type` defaults to `query`; `unspecified` explicitly opts out. Legacy omission retains each model's existing behavior. The model is default off and is callable only when it appears in `GET /v1/models?type=embedding`. Authenticate with an `X-API-Key` carrying `grid:write` (prepaid credits), or omit it and retry the `402` challenge with `X-Payment`. EG2 input and results are persisted only as sealed envelopes. Terminal input becomes purge-eligible after 30 minutes and results after one hour; the hourly purge makes practical upper bounds about 90 minutes and two hours. Plaintext node error text is never persisted. ## OpenAPI ````yaml /api-reference/openapi.json post /v1/embeddings openapi: 3.1.0 info: title: x402 Singularity Layer API description: >- OpenAPI-backed reference for marketplace discovery, payment routes, webhooks, wallet-first auth, agent endpoints, and ERC-8004 flows. version: 1.0.0 servers: - url: https://api.x402layer.cc security: [] tags: - name: Marketplace description: Public discovery and listing lookup - name: Public Endpoints description: Public endpoint metadata and hosted checkout context - name: Public Payment Links description: Hosted public payment-link lookup - name: Payments description: Hosted x402 payment challenge routes - name: Receipts description: Signed receipt lookup and verification helpers - name: Ratings description: Public listing ratings and authenticated rating actions - name: Webhooks description: Seller webhook management API - name: Agent Auth description: Wallet-first challenge and verification routes - name: Agent Endpoints description: Create, read, top up, and delete agent endpoints - name: ERC-8004 description: Agent registry and registration lifecycle routes - name: Marketplace Agents description: Public ERC-8004 marketplace discovery routes - name: Compute Catalog description: Compute plans, regions, and OS catalog - name: Compute Instances description: Provision, inspect, extend, and destroy compute instances - name: Compute API Keys description: API keys for compute agent access - name: Fundraiser Campaigns description: List, view, create, and edit fundraiser campaigns - name: Fundraiser Contributions description: Record and list campaign contributions - name: Fundraiser Comments description: Campaign comment threads - name: Fundraiser Media description: Campaign image uploads and OG images - name: Enterprise description: >- Enterprise partner configuration, endpoint listing, revenue stats, and transaction ledger - name: Staking description: Agentic $SGL staking - name: SGL Grid description: >- Decentralized, confidential, OpenAI-compatible inference served by attested TEE nodes. - name: Compute Credits description: Prepaid USDC credit balance shared across Machines and Grid. - name: Agent Pods description: >- Deploy and manage hosted agents (Agent Pods), plus the pod's OpenAI-compatible adapter for external clients. - name: Agent Pods API description: >- The programmatic `/pods/v1` surface: create, drive and destroy Agent Pods with a single `X-API-Key`. Distinct from the Agent Pods dashboard routes, which expect a wallet signature or a browser session. paths: /v1/embeddings: servers: - url: https://grid.x402compute.cc post: tags: - SGL Grid summary: Create embeddings description: >- OpenAI-compatible embeddings with input-only billing. Existing text models accept a string or string array. `embeddinggemma-2` also accepts ordered text, image, audio, and video content parts and returns one normalized vector per top-level item. Omitted EG2 `input_type` defaults to `query`; `unspecified` explicitly opts out. Legacy omission retains each model's existing behavior. The model is default off and is callable only when it appears in `GET /v1/models?type=embedding`. Authenticate with an `X-API-Key` carrying `grid:write` (prepaid credits), or omit it and retry the `402` challenge with `X-Payment`. EG2 input and results are persisted only as sealed envelopes. Terminal input becomes purge-eligible after 30 minutes and results after one hour; the hourly purge makes practical upper bounds about 90 minutes and two hours. Plaintext node error text is never persisted. parameters: - name: X-API-Key in: header required: false schema: type: string example: x402c_... description: >- Compute/Grid API key with `grid:write` scope. Requests debit prepaid credits. Omit to use the x402 challenge. - name: X-Payment in: header required: false schema: type: string description: >- x402 payment payload. Send after receiving the endpoint's `402` challenge. requestBody: required: true content: application/json: schema: type: object additionalProperties: false required: - model - input properties: model: type: string example: embeddinggemma-2 input: description: >- A single text string; 1-2048 strings for legacy text models; or 1-16 ordered string/structured items for EmbeddingGemma 2. Each item produces one vector at the matching response index. anyOf: - type: string minLength: 1 - type: array minItems: 1 maxItems: 2048 items: type: string minLength: 1 description: Legacy text-only batch. - type: array minItems: 1 maxItems: 16 items: oneOf: - type: string minLength: 1 - type: object additionalProperties: false required: - content properties: content: type: array minItems: 1 maxItems: 16 description: >- Ordered content parts. Up to eight images, one audio part, and one video part per item. items: oneOf: - type: object title: Text part additionalProperties: false required: - type - text properties: type: type: string enum: - text text: type: string minLength: 1 - type: object title: Image part additionalProperties: false required: - type - media properties: type: type: string enum: - image media: type: object additionalProperties: false required: - encoding - mime_type - data - sha256 properties: encoding: type: string enum: - base64 mime_type: type: string enum: - image/jpeg - image/png - image/webp data: type: string description: >- Canonical base64 for at most 8 MiB decoded bytes. sha256: type: string pattern: ^[a-f0-9]{64}$ description: >- SHA-256 of the decoded bytes, lowercase hexadecimal. - type: object title: Audio part additionalProperties: false required: - type - media - duration_seconds properties: type: type: string enum: - audio duration_seconds: type: number exclusiveMinimum: 0 maximum: 30 description: >- Declared duration. The runtime verifies the decoded duration. media: type: object additionalProperties: false required: - encoding - mime_type - data - sha256 properties: encoding: type: string enum: - base64 mime_type: type: string enum: - audio/wav - audio/flac - audio/mpeg data: type: string description: >- Canonical base64 for at most 8 MiB decoded bytes. sha256: type: string pattern: ^[a-f0-9]{64}$ - type: object title: Video part additionalProperties: false required: - type - media - duration_seconds properties: type: type: string enum: - video duration_seconds: type: number exclusiveMinimum: 0 maximum: 32 description: >- Declared duration. Video is sampled at up to 1 fps and 32 frames. media: type: object additionalProperties: false required: - encoding - mime_type - data - sha256 properties: encoding: type: string enum: - base64 mime_type: type: string enum: - video/mp4 data: type: string description: >- Canonical base64 for at most 16 MiB decoded bytes. sha256: type: string pattern: ^[a-f0-9]{64}$ dimensions: description: >- Optional model-specific output dimension. Omit for the model's native dimension. Unsupported model/dimension pairs return 400. anyOf: - title: EmbeddingGemma 2 type: integer enum: - 768 - 512 - 256 - 128 - title: Nomic Embed Text v1.5 type: integer enum: - 768 - 512 - 256 - 128 - 64 - title: Mixedbread Embed Large v1 type: integer enum: - 1024 - 512 - 256 - title: Fixed-size text models type: integer enum: - 384 - 768 - 1024 description: >- The selected fixed-size model accepts only its own native value. input_type: description: >- Optional model-specific retrieval behavior. This schema intentionally has no global default. anyOf: - title: Legacy text embedding models type: string enum: - query - document description: Omission retains the legacy model/runtime behavior. - title: EmbeddingGemma 2 type: string enum: - query - document - unspecified description: >- Omission is sealed as query. Use unspecified only to opt out of query/document prefixing. encoding_format: type: string enum: - float default: float tier: type: string enum: - standard - confidential use_credits: type: boolean description: >- Use an authenticated wallet session's credits when no API key is supplied. user: type: string description: Optional OpenAI-compatible caller identifier. examples: text: summary: Text batch value: model: embeddinggemma-2 input: - search query - document text dimensions: 256 input_type: query mixed: summary: Ordered text and image value: model: embeddinggemma-2 input: - content: - type: text text: Product photo - type: image media: encoding: base64 mime_type: image/png data: iVBORw0KGgo... sha256: >- 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef dimensions: 256 input_type: document responses: '200': description: >- One finite, unit-normalized float vector per input item, ordered by index. content: application/json: schema: type: object required: - object - data - model - usage properties: object: type: string enum: - list data: type: array items: type: object required: - object - index - embedding properties: object: type: string enum: - embedding index: type: integer minimum: 0 embedding: type: array items: type: number format: float model: type: string usage: type: object required: - prompt_tokens - total_tokens - cost_usd properties: prompt_tokens: type: integer minimum: 1 total_tokens: type: integer minimum: 1 description: >- Equal to prompt_tokens. Embeddings have no output tokens. cost_usd: type: number minimum: 0 breakdown: type: object description: Present for EmbeddingGemma 2. required: - text - image - audio - video properties: text: type: integer minimum: 0 image: type: integer minimum: 0 audio: type: integer minimum: 0 video: type: integer minimum: 0 processor_revision: type: string description: Present for EmbeddingGemma 2. embedding_protocol: type: string enum: - embedding-multimodal-v1 billing_pending: type: boolean description: >- Present and true only when x402 capture succeeded but durable accounting finalization is still recovering. Do not resubmit the paid request. job_id: type: string format: uuid description: >- Present with billing_pending so accounting recovery is correlated idempotently. '400': description: >- `invalid_request_error`; stable EG2 codes are `embedding_input_invalid` and `embedding_context_overflow`. These input failures are not charged and do not trigger paid failover. '401': description: '`invalid_api_key` or `invalid_session`.' '402': description: >- `payment_required`, `insufficient_credits`, `pod_cap_reached`, or `payment_error`. '403': description: '`insufficient_scope`: the API key lacks `grid:write`.' '404': description: >- `model_not_found` for an unknown model id. When the entire embeddings route is disabled, the route returns plain `Not found`. '413': description: Encoded JSON body exceeds 24 MiB. '500': description: >- `server_error`: dispatch or billing infrastructure failed. Inspect the response message before retrying. '502': description: >- `inference_error`: unreadable, invalid, or failed node output. Invalid vectors are never returned or billed. '503': description: >- `model_not_available` when the release/capability boundary is unavailable; `node_not_available` when a claimed node loses negotiated confidential transport; or `server_error` when the payment service is not configured. '504': description: '`timeout`: inference timed out and was not charged.' ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.