> For the complete documentation index, see [llms.txt](https://docs.nansen.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nansen.ai/api/trade/spot-trading/prepare.md). # Turn a quote into a signable transaction ## Turn a quote into a signable transaction > Turn a quote into a transaction you can sign.\ > \ > Pass one quote object from the quote endpoint, unmodified, together with the wallet that will\ > sign. The response carries a transaction built and ready to sign, with a fresh blockhash on\ > Solana and a simulation already run against it.\ > \ > \- \*\*Solana:\*\* \`transaction\` is a base64-encoded serialized \`VersionedTransaction\`. Deserialize,\ > sign, and send it to the execute endpoint base64-encoded.\ > \- \*\*EVM (Base):\*\* \`swapTxData\` holds the transaction fields to sign. When \`needsApproval\` is\ > true, sign and send \`approvalTxData\` first and wait for it to confirm.\ > \ > This step is optional for same-chain swaps, where the quote already carries signable\ > transaction data — but it is \*\*required for swaps out of Solana to another chain\*\*, whose quotes\ > carry routing instructions rather than a transaction. Preferring this endpoint everywhere means\ > one signing path instead of one per route, and it applies the network fee floor that keeps\ > Solana bridge transactions from being dropped while they wait to be included.\ > \ > The transaction is not broadcast here. Send the signed result to the execute endpoint. ```json {"openapi":"3.1.0","info":{"title":"Nansen API","version":"1.0.0"},"servers":[{"url":"https://api.nansen.ai"}],"security":[{"ApiKeyAuth":[]}],"components":{"securitySchemes":{"ApiKeyAuth":{"type":"apiKey","in":"header","name":"apikey","description":"API key for authentication"}},"schemas":{"TradingPrepareRequest":{"properties":{"chain":{"type":"string","enum":["base","solana"],"title":"Chain","description":"Chain the quote is on: 'solana' or 'base'"},"wallet_address":{"type":"string","title":"Wallet Address","description":"Wallet that will sign and send the transaction"},"quote":{"additionalProperties":true,"type":"object","title":"Quote","description":"One quote object, copied verbatim from the `quotes` array returned by the quote endpoint. Do not modify it — it carries the routing data needed to rebuild the transaction."},"skip_simulation":{"type":"boolean","title":"Skip Simulation","description":"Skip the pre-signing simulation. Simulation catches failures before you spend a signature, so leave this off unless you are re-preparing a quote you have already validated.","default":false}},"type":"object","required":["chain","wallet_address","quote"],"title":"TradingPrepareRequest","description":"A quote plus the wallet that will sign it."},"TradingPrepareResponse":{"properties":{"transaction":{"anyOf":[{"type":"string"}],"title":"Transaction","description":"Serialized unsigned transaction, base64-encoded (Solana only)"},"swapTxData":{"anyOf":[{"additionalProperties":true,"type":"object"}],"title":"Swaptxdata","description":"Unsigned transaction fields to sign and send (EVM only)"},"needsApproval":{"type":"boolean","title":"Needsapproval","description":"Whether the sell token needs an approval transaction first (EVM only)","default":false},"approvalTxData":{"anyOf":[{"additionalProperties":true,"type":"object"}],"title":"Approvaltxdata","description":"Unsigned approval transaction, present only when an approval is needed"},"simulationPassed":{"anyOf":[{"type":"boolean"}],"title":"Simulationpassed","description":"Whether the pre-signing simulation succeeded, or `null` when no simulation ran. Nothing is simulated when you set `skip_simulation`, and on EVM nothing is simulated while `needsApproval` is true, because a swap always fails simulation until the approval is confirmed."}},"additionalProperties":true,"type":"object","title":"TradingPrepareResponse","description":"A signable transaction built from a quote."},"ErrorEnvelope":{"type":"object","required":["error","message","code","status","request_id","doc_url"],"properties":{"error":{"type":"string","description":"Human-readable error category."},"message":{"type":"string","description":"Human-readable explanation of the error."},"code":{"type":"string","enum":["missing_field","unknown_field","invalid_field_value","invalid_address_format","invalid_date_format","invalid_date_range","mutually_exclusive_fields","value_out_of_range","too_many_items","unauthenticated","forbidden","geo_blocked","plan_upgrade_required","insufficient_credits","rate_limit_exceeded","not_found","method_not_allowed","conflict","payload_too_large","query_timeout","query_too_large","upstream_unavailable","internal_error"],"description":"Stable machine-readable error code."},"status":{"type":"integer","description":"HTTP status code returned for the request."},"request_id":{"type":["string","null"],"description":"Identifier for the request, when available."},"doc_url":{"type":"string","format":"uri","description":"Link to the error-code reference documentation, anchored to this error's code."},"param":{"type":"string","description":"Request parameter associated with the error."},"retry_after":{"type":"integer","minimum":0,"description":"Seconds to wait before retrying the request."}}}},"headers":{"XNansenCreditsCost":{"description":"Quoted credit cost of this request. It is present on successful responses and errors reached after pricing, but absent when a request is rejected before pricing. A value of 0 means plan credits do not apply.","schema":{"type":"string"}},"XRequestId":{"description":"Unique identifier for this request, returned on every response. Uses the upstream-assigned request id when available; otherwise echoes a caller-supplied X-Request-Id or generates an id. Include this value in support requests.","schema":{"type":"string"}},"XNansenCreditsUsed":{"description":"Credits actually deducted for this request. Can differ from the quoted cost, for example 0 when the request was rejected.","schema":{"type":"string"}},"XNansenCreditsRemaining":{"description":"Total credits remaining in the user's account after this request","schema":{"type":"string"}},"PaymentReceipt":{"description":"Base64url-encoded MPP receipt returned on successful paid requests via Authorization: Payment","schema":{"type":"string"}},"RateLimitLimit":{"description":"Combined rate limit across all configured time windows","schema":{"type":"string"}},"RateLimitRemaining":{"description":"Number of requests remaining in the current limiting window","schema":{"type":"string"}},"RateLimitReset":{"description":"Seconds until the rate limit window resets. A delta in seconds, not a Unix timestamp.","schema":{"type":"string"}},"XRateLimitLimit":{"description":"Request limit for the most constrained app-enforced window","schema":{"type":"string"}},"XRateLimitRemaining":{"description":"Requests remaining in the most constrained app-enforced window","schema":{"type":"string"}},"XRateLimitReset":{"description":"Seconds until the most constrained app-enforced window resets. A delta in seconds, not a Unix timestamp: it is at least 1 and never exceeds the window span.","schema":{"type":"string"}},"XRateLimitLimitSecond":{"description":"Maximum requests allowed per second","schema":{"type":"string"}},"XRateLimitRemainingSecond":{"description":"Requests remaining in the current second","schema":{"type":"string"}},"XRateLimitLimitMinute":{"description":"Maximum requests allowed per minute","schema":{"type":"string"}},"XRateLimitRemainingMinute":{"description":"Requests remaining in the current minute","schema":{"type":"string"}},"RetryAfter":{"description":"Number of seconds to wait before making a new request","schema":{"type":"string"}},"XNansenRateLimitScope":{"description":"Window that caused an enforced rate-limit rejection: `second` or `minute` for global plan windows, or `endpoint` for an endpoint-specific window. This is an open set; clients should handle unknown future values with generic rate-limit behavior.","schema":{"type":"string"}}},"responses":{"BadRequestError":{"description":"Bad Request - Invalid request parameters or malformed request","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","properties":{"detail":{"type":"string"}}}]}}}},"UnauthorizedError":{"description":"Authentication error - No API key found in request","headers":{"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","properties":{"detail":{"type":"string"}}}]}}}},"ForbiddenError":{"description":"Forbidden - User does not have required subscription tier or has exceeded credit limit","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Nansen-Credits-Used":{"$ref":"#/components/headers/XNansenCreditsUsed"},"X-Nansen-Credits-Remaining":{"$ref":"#/components/headers/XNansenCreditsRemaining"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","properties":{"detail":{"type":"string"}}}]}}}},"NotFoundError":{"description":"Not Found - The requested resource was not found","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorEnvelope"}}}},"ValidationError":{"description":"Validation error - Invalid request parameters","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","properties":{"errors":{"type":"array","description":"Per-field request-validation errors, in the order they were detected. This field is absent from other 422 responses. The top-level error, message, and code reflect the primary error, which is not always the first entry. When a request produces an unusually large number of errors the list is truncated and a final entry reports how many were omitted.","items":{"type":"object","required":["field","message","code"],"properties":{"field":{"type":"string","description":"Path of the request field that failed validation, prefixed with its location in the request (body, query, path, header, or cookie) and including array indices. Unlike param, this path keeps the location prefix and array indices."},"message":{"type":"string","description":"Human-readable explanation of the field error."},"code":{"type":"string","enum":["missing_field","unknown_field","invalid_field_value","invalid_address_format","invalid_date_format","invalid_date_range","mutually_exclusive_fields","value_out_of_range","too_many_items"],"description":"Stable machine-readable error code."}}}}}}]}}}},"TooManyRequestsError":{"description":"Too Many Requests - Rate limit exceeded","content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","properties":{"detail":{"type":"string"},"retry_after":{"type":"integer","description":"Seconds to wait before retrying"}}}]}}},"headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"Retry-After":{"$ref":"#/components/headers/RetryAfter"},"X-RateLimit-Limit":{"$ref":"#/components/headers/XRateLimitLimit"},"X-RateLimit-Remaining":{"$ref":"#/components/headers/XRateLimitRemaining"},"X-RateLimit-Reset":{"$ref":"#/components/headers/XRateLimitReset"},"X-Nansen-RateLimit-Scope":{"$ref":"#/components/headers/XNansenRateLimitScope"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}}},"InternalServerError":{"description":"Internal Server Error - An unexpected error occurred","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"$ref":"#/components/schemas/ErrorEnvelope"}}}},"BadGatewayError":{"description":"Bad Gateway - Upstream service unavailable","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"Retry-After":{"$ref":"#/components/headers/RetryAfter"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","required":["retry_after"],"properties":{"retry_after":{"type":"integer","description":"Seconds to wait before retrying"}}}]}}}},"ServiceUnavailableError":{"description":"Service Unavailable - Service temporarily unavailable","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"Retry-After":{"$ref":"#/components/headers/RetryAfter"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","required":["retry_after"],"properties":{"retry_after":{"type":"integer","description":"Seconds to wait before retrying"}}}]}}}},"GatewayTimeoutError":{"description":"Gateway Timeout - Upstream service timed out","headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"Retry-After":{"$ref":"#/components/headers/RetryAfter"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"}},"content":{"application/json":{"schema":{"allOf":[{"$ref":"#/components/schemas/ErrorEnvelope"},{"type":"object","required":["retry_after"],"properties":{"retry_after":{"type":"integer","description":"Seconds to wait before retrying"}}}]}}}}}},"paths":{"/api/v1/trade/prepare":{"post":{"tags":["Trading"],"summary":"Turn a quote into a signable transaction","description":"Turn a quote into a transaction you can sign.\n\nPass one quote object from the quote endpoint, unmodified, together with the wallet that will\nsign. The response carries a transaction built and ready to sign, with a fresh blockhash on\nSolana and a simulation already run against it.\n\n- **Solana:** `transaction` is a base64-encoded serialized `VersionedTransaction`. Deserialize,\n sign, and send it to the execute endpoint base64-encoded.\n- **EVM (Base):** `swapTxData` holds the transaction fields to sign. When `needsApproval` is\n true, sign and send `approvalTxData` first and wait for it to confirm.\n\nThis step is optional for same-chain swaps, where the quote already carries signable\ntransaction data — but it is **required for swaps out of Solana to another chain**, whose quotes\ncarry routing instructions rather than a transaction. Preferring this endpoint everywhere means\none signing path instead of one per route, and it applies the network fee floor that keeps\nSolana bridge transactions from being dropped while they wait to be included.\n\nThe transaction is not broadcast here. Send the signed result to the execute endpoint.","operationId":"prepare_trading_api_v1_trade_prepare_post","requestBody":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/TradingPrepareRequest"}}},"required":true},"responses":{"200":{"description":"An unsigned transaction ready to sign","content":{"application/json":{"schema":{"$ref":"#/components/schemas/TradingPrepareResponse"}}},"headers":{"X-Nansen-Credits-Cost":{"$ref":"#/components/headers/XNansenCreditsCost"},"X-Request-Id":{"$ref":"#/components/headers/XRequestId"},"X-Nansen-Credits-Used":{"$ref":"#/components/headers/XNansenCreditsUsed"},"X-Nansen-Credits-Remaining":{"$ref":"#/components/headers/XNansenCreditsRemaining"},"Payment-Receipt":{"$ref":"#/components/headers/PaymentReceipt"},"RateLimit-Limit":{"$ref":"#/components/headers/RateLimitLimit"},"RateLimit-Remaining":{"$ref":"#/components/headers/RateLimitRemaining"},"RateLimit-Reset":{"$ref":"#/components/headers/RateLimitReset"},"X-RateLimit-Limit":{"$ref":"#/components/headers/XRateLimitLimit"},"X-RateLimit-Remaining":{"$ref":"#/components/headers/XRateLimitRemaining"},"X-RateLimit-Reset":{"$ref":"#/components/headers/XRateLimitReset"},"X-RateLimit-Limit-Second":{"$ref":"#/components/headers/XRateLimitLimitSecond"},"X-RateLimit-Remaining-Second":{"$ref":"#/components/headers/XRateLimitRemainingSecond"},"X-RateLimit-Limit-Minute":{"$ref":"#/components/headers/XRateLimitLimitMinute"},"X-RateLimit-Remaining-Minute":{"$ref":"#/components/headers/XRateLimitRemainingMinute"}}},"400":{"description":"Bad Request","$ref":"#/components/responses/BadRequestError"},"401":{"description":"Unauthorized","$ref":"#/components/responses/UnauthorizedError"},"403":{"description":"Forbidden","$ref":"#/components/responses/ForbiddenError"},"404":{"description":"Not Found","$ref":"#/components/responses/NotFoundError"},"422":{"description":"Unprocessable Content","$ref":"#/components/responses/ValidationError"},"429":{"description":"Too Many Requests","$ref":"#/components/responses/TooManyRequestsError"},"500":{"description":"Internal Server Error","$ref":"#/components/responses/InternalServerError"},"502":{"description":"Bad Gateway","$ref":"#/components/responses/BadGatewayError"},"503":{"description":"Service Unavailable","$ref":"#/components/responses/ServiceUnavailableError"},"504":{"description":"Gateway Timeout","$ref":"#/components/responses/GatewayTimeoutError"}}}}}} ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.nansen.ai/api/trade/spot-trading/prepare.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.