> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # List match candidates for a transaction > Returns a ranked list of opposite-side unmatched transactions the engine considers plausible counterparts for the target transaction, each with a confidence score, the rule that drove it, a per-component rationale (the "why"), and amount/date deltas. Powers the exception-resolution and manual-match candidate pickers. Scope: proposals are scored by the deterministic rule engine over raw transaction amounts and do NOT apply run-time fee normalization or the FX-variance band; only 1:1 pairwise counterparts are returned. A target that is not UNMATCHED (for example an exception raised on an already matched leg) has no counterpart and returns an empty list. ## OpenAPI ````yaml /pt/openapi/v3-current/matcher.yaml get /v1/matching/candidates openapi: 3.1.0 info: title: Matcher APIs description: >- Complete API reference for the Matcher reconciliation engine, providing automated transaction matching between Midaz Ledger and external systems. version: 6.1.0 license: name: Lerian Studio General License servers: - url: https://matcher.sandbox.lerian.net security: [] paths: /v1/matching/candidates: get: tags: - Matching summary: List match candidates for a transaction description: >- Returns a ranked list of opposite-side unmatched transactions the engine considers plausible counterparts for the target transaction, each with a confidence score, the rule that drove it, a per-component rationale (the "why"), and amount/date deltas. Powers the exception-resolution and manual-match candidate pickers. Scope: proposals are scored by the deterministic rule engine over raw transaction amounts and do NOT apply run-time fee normalization or the FX-variance band; only 1:1 pairwise counterparts are returned. A target that is not UNMATCHED (for example an exception raised on an already matched leg) has no counterpart and returns an empty list. operationId: listMatchCandidates parameters: - description: Context ID the transaction belongs to explode: false in: query name: contextId required: true schema: description: Context ID the transaction belongs to format: uuid type: string - description: >- Target transaction to find counterparts for. For an exception, resolve its transaction id first, then pass it here. explode: false in: query name: transactionId required: true schema: description: >- Target transaction to find counterparts for. For an exception, resolve its transaction id first, then pass it here. format: uuid type: string - description: Maximum number of ranked proposals to return explode: false in: query name: limit schema: default: 50 description: Maximum number of ranked proposals to return format: int64 maximum: 200 minimum: 1 type: integer responses: '200': content: application/json: schema: $ref: '#/components/schemas/CandidateProposalsResponse' description: OK '400': description: The request contains invalid parameters or payload. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' examples: 400-transaction-id-is-required: $ref: '#/components/examples/400-transaction-id-is-required' '401': $ref: '#/components/responses/Unauthorized' '403': description: >- You do not have permission to access this resource, or the context is not active. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' examples: TenantClaimRequired: summary: Tenant claim missing value: type: https://errors.lerian.studio/v1/MTCH-0004 title: Forbidden status: 403 detail: tenant claim required code: MTCH-0004 mtch-0012-context-is-not-active: $ref: '#/components/examples/mtch-0012-context-is-not-active' '404': description: The requested resource was not found. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' examples: mtch-0005-context-not-found: $ref: '#/components/examples/mtch-0005-context-not-found' mtch-0005-target-transaction-not-found-in-context: $ref: >- #/components/examples/mtch-0005-target-transaction-not-found-in-context mtch-0005-reconciliation-context-not-found: $ref: >- #/components/examples/mtch-0005-reconciliation-context-not-found '422': $ref: '#/components/responses/ValidationFailed' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalServerError' security: - BearerAuth: [] components: schemas: CandidateProposalsResponse: additionalProperties: false properties: items: description: Ranked candidate proposals (highest score first) items: $ref: '#/components/schemas/CandidateProposalResponse' maxItems: 200 type: - array - 'null' targetTransactionId: description: The transaction counterparts were proposed for examples: - 550e8400-e29b-41d4-a716-446655440000 type: string required: - targetTransactionId - items type: object Detail: additionalProperties: false properties: code: description: >- Stable, machine-readable domain error code scoped to the emitting service (format: -NNNN). examples: - ERR-0001 type: string detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string errors: description: Optional list of individual error details items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string upstream: $ref: '#/components/schemas/Upstream' description: >- RFC 9457 extension member: the error a proxied third-party provider reported. Absent unless the emitting service explicitly surfaced one. type: object CandidateProposalResponse: additionalProperties: false properties: amountDelta: description: candidate.amount - target.amount as a signed decimal string examples: - '0.00' type: string dateDeltaDays: description: Signed whole-day difference (candidate - target) in UTC days examples: - 0 format: int64 type: integer ruleId: description: Identifier of the rule that produced the best score for this pair examples: - 550e8400-e29b-41d4-a716-446655440000 type: string ruleType: description: Strategy of the rule that produced the best score enum: - EXACT - TOLERANCE - DATE_LAG - FUZZY examples: - EXACT type: string score: description: Engine confidence score for this pair (0..100) examples: - 90 format: int64 maximum: 100 minimum: 0 type: integer transaction: $ref: '#/components/schemas/CandidateTransactionView' description: The proposed counterpart transaction why: $ref: '#/components/schemas/CandidateWhy' description: Per-component rationale for the score required: - transaction - ruleId - ruleType - score - why - amountDelta - dateDeltaDays type: object ErrorDetail: additionalProperties: false properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' type: string message: description: Error message text type: string value: description: The value at the given location type: object Upstream: additionalProperties: false properties: code: description: The upstream provider's own error code, verbatim. examples: - E4001 type: string message: description: >- The upstream provider's own error message, verbatim (bounded, never its raw response body). examples: - account not found at provider type: string type: object RateLimitErrorResponse: description: >- Flat body that the rate limiter returns. `code` is the HTTP status as a number. type: object required: - code - title - message properties: code: type: integer description: HTTP status code. example: 429 title: type: string description: Error type. example: rate_limit_exceeded message: type: string description: Human-readable error message. example: rate limit exceeded CandidateTransactionView: additionalProperties: false properties: amount: description: Candidate amount as a decimal string examples: - '100.50' type: string baseAmount: description: >- Candidate base-currency amount, when the transaction was FX-converted examples: - '100.50' type: string currency: description: Candidate ISO 4217 currency code examples: - USD type: string date: description: Candidate transaction date (RFC 3339 timestamp) examples: - '2025-01-15T10:30:00Z' type: string externalId: description: External reference/id of the candidate transaction examples: - INV-1234 type: string id: description: Candidate transaction ID (UUID) examples: - 550e8400-e29b-41d4-a716-446655440000 type: string sourceId: description: Source the candidate belongs to (UUID) examples: - 550e8400-e29b-41d4-a716-446655440001 type: string required: - id - sourceId - amount - currency - date type: object CandidateWhy: additionalProperties: false properties: amountMatch: description: >- Whether the amounts are literally equal on the matched rule's sign axis (not merely within tolerance) examples: - true type: boolean currencyMatch: description: Whether the currency codes are literally equal and both non-empty examples: - true type: boolean dateMatch: description: >- Whether both transactions fall on the same UTC calendar day (not the full DATE_LAG window) examples: - true type: boolean matchedKeys: description: >- Per-key agreement for the matched rule's configured composite match fields (matchFields), in field-name order. Empty when the matched rule declares no active matchFields. items: $ref: '#/components/schemas/CandidateMatchedKey' type: - array - 'null' referenceScore: description: Graded 0..1 reference-similarity contribution examples: - 1 format: double maximum: 1 minimum: 0 type: number required: - amountMatch - currencyMatch - dateMatch - referenceScore type: object CandidateMatchedKey: additionalProperties: false properties: agreed: description: >- Whether the two transactions agree on this key under the field's configured mode/tolerance — the engine's own per-field gate decision examples: - true type: boolean field: description: Name of the configured composite match field (metadata key) examples: - payment_id type: string required: - field - agreed type: object examples: 400-transaction-id-is-required: summary: Transaction id is required value: title: Bad Request status: 400 detail: A target transaction id is required to list match candidates. mtch-0012-context-is-not-active: summary: Context is not active value: type: https://errors.lerian.studio/v1/MTCH-0012 title: Forbidden status: 403 detail: context is not active code: MTCH-0012 mtch-0005-context-not-found: summary: Context not found value: type: https://errors.lerian.studio/v1/MTCH-0005 title: Not Found status: 404 detail: >- No reconciliation context matches this id; check the context id and try again. code: MTCH-0005 mtch-0005-target-transaction-not-found-in-context: summary: Target transaction not found in context value: type: https://errors.lerian.studio/v1/MTCH-0005 title: Not Found status: 404 detail: >- The target transaction was not found in this context; check the transaction id. code: MTCH-0005 mtch-0005-reconciliation-context-not-found: summary: Reconciliation context not found value: type: https://errors.lerian.studio/v1/MTCH-0005 title: Not Found status: 404 detail: >- No reconciliation context matches this id; check the context id and try again. code: MTCH-0005 responses: Unauthorized: description: The request lacks valid authentication credentials. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' examples: MissingToken: summary: Missing token value: type: https://errors.lerian.studio/v1/AUT-0006 title: Token Missing status: 401 detail: >- A valid token must be provided in the request header. Please include a token and try again. code: AUT-0006 InvalidToken: summary: Invalid token value: type: https://errors.lerian.studio/v1/AUT-0007 title: Invalid Token status: 401 detail: >- The provided token is expired, invalid or malformed. Please provide a valid token and try again. code: AUT-0007 ValidationFailed: description: >- The request failed validation. The `errors` list names each value that failed. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' example: title: Unprocessable Entity status: 422 detail: validation failed errors: - message: expected required property name to be present location: body TooManyRequests: description: >- The request exceeded the rate limit. Wait the number of seconds in `Retry-After`, then retry. headers: 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' content: application/json: schema: $ref: '#/components/schemas/RateLimitErrorResponse' example: code: 429 title: rate_limit_exceeded message: rate limit exceeded InternalServerError: description: An unexpected error occurred on the server. content: application/problem+json: schema: $ref: '#/components/schemas/Detail' example: type: https://errors.lerian.studio/v1/MTCH-0002 title: Internal Server Error status: 500 detail: internal error code: MTCH-0002 text/plain: schema: type: string example: Internal Server Error headers: RetryAfter: description: Seconds to wait before you retry. schema: type: integer example: 30 XRateLimitLimit: description: Requests allowed in the current window. schema: type: integer example: 100 XRateLimitRemaining: description: Requests left in the current window. Always `0` on a `429`. schema: type: integer example: 0 XRateLimitReset: description: Unix time, in seconds, when the current window resets. schema: type: integer example: 1767225600 securitySchemes: BearerAuth: bearerFormat: JWT description: 'Bearer token authentication (format: "Bearer {token}")' scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.