> ## Documentation Index > Fetch the complete documentation index at: https://docs.haiqu.ai/llms.txt > Use this file to discover all available pages before exploring further. # Postprocess Measurement Counts > Improve sampled QUBO solutions with Haiqu's classical post-processing. Use this tool after a QAOA or VQE sampling run to turn noisy measured bitstrings into better solutions. It applies bit-flip local search against the QUBO objective and runs synchronously, so results come back immediately. When to Use: - Call this after ``run_circuits_on_qpu_or_simulator`` returns counts for a QUBO problem, which is the last step of the QAOA workflow. - Call this when the user asks for the best solution or objective value rather than the raw measurement distribution. Constraints: - Provide exactly one of ``counts`` or ``run_job_id``. Prefer ``run_job_id`` so large count dictionaries stay out of the tool call. - ``lp_problem`` must be the same objective the circuit was built from, otherwise the reported costs are meaningless. - Only the best ``max_solutions`` solutions are returned; the response reports ``total_solutions`` and sets ``truncated`` when it omits some. Notes: - Report ``best_bitstring`` and ``best_cost`` first; the solution list is supporting detail. - Implausible costs usually mean the LP problem does not match the circuit that produced the counts, not a post-processing failure. Args: user: Authenticated user resolved from the API key. data: Problem definition plus inline counts or a run job reference. db: Active database session. Returns: The best solutions found, ordered by objective value, with a summary. Raises: HTTPException: Raised with ``400`` when neither or both count inputs are given, ``404`` when a referenced job is unavailable, ``409`` when the referenced job has no usable counts, or ``500`` when post-processing fails. ## OpenAPI ````yaml https://api.haiqu.ai/openapi.json post /ai/postprocess_measurement_counts openapi: 3.1.0 info: title: Haiqu API summary: Haiqu RESTful API service. description: Cloud service providing the access to Haiqu cloud runtime contact: name: Haiqu Inc. url: https://haiqu.ai/ email: info@haiqu.ai version: 1.5.0 servers: [] security: [] paths: /ai/postprocess_measurement_counts: post: summary: Postprocess Measurement Counts description: >- Improve sampled QUBO solutions with Haiqu's classical post-processing. Use this tool after a QAOA or VQE sampling run to turn noisy measured bitstrings into better solutions. It applies bit-flip local search against the QUBO objective and runs synchronously, so results come back immediately. When to Use: - Call this after ``run_circuits_on_qpu_or_simulator`` returns counts for a QUBO problem, which is the last step of the QAOA workflow. - Call this when the user asks for the best solution or objective value rather than the raw measurement distribution. Constraints: - Provide exactly one of ``counts`` or ``run_job_id``. Prefer ``run_job_id`` so large count dictionaries stay out of the tool call. - ``lp_problem`` must be the same objective the circuit was built from, otherwise the reported costs are meaningless. - Only the best ``max_solutions`` solutions are returned; the response reports ``total_solutions`` and sets ``truncated`` when it omits some. Notes: - Report ``best_bitstring`` and ``best_cost`` first; the solution list is supporting detail. - Implausible costs usually mean the LP problem does not match the circuit that produced the counts, not a post-processing failure. Args: user: Authenticated user resolved from the API key. data: Problem definition plus inline counts or a run job reference. db: Active database session. Returns: The best solutions found, ordered by objective value, with a summary. Raises: HTTPException: Raised with ``400`` when neither or both count inputs are given, ``404`` when a referenced job is unavailable, ``409`` when the referenced job has no usable counts, or ``500`` when post-processing fails. operationId: postprocess_measurement_counts requestBody: content: application/json: schema: $ref: '#/components/schemas/ContextPostprocessSubmitModel' required: true responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/ContextPostprocessResultModel' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' security: - APIKeyQuery: [] - APIKeyHeader: [] components: schemas: ContextPostprocessSubmitModel: properties: lp_problem: type: string title: Lp Problem description: QUBO problem serialized in LP file format. counts: anyOf: - additionalProperties: type: number type: object - type: 'null' title: Counts description: >- Measured bitstring counts, for example `{'0101': 120, '1010': 87}`. Provide this or `run_job_id`, not both. run_job_id: anyOf: - type: string - type: 'null' title: Run Job Id description: >- Run job whose stored measurement results are used as `counts`, so large count dictionaries never have to be passed inline. Provide this or `counts`. params: anyOf: - additionalProperties: true type: object - type: 'null' title: Params description: >- Optional overrides: `method` (`none`, `bitflip_incremental`, `bitflip_steepest_descent`), `postprocess_iterations`, `use_fast_eval`, `seed`. max_solutions: type: integer maximum: 500 minimum: 1 title: Max Solutions description: Maximum number of solutions returned inline, best cost first. default: 20 type: object required: - lp_problem title: ContextPostprocessSubmitModel description: |- Define payload for post-processing QUBO measurement counts. Attributes: lp_problem: QUBO problem in LP file format. counts: Measured bitstring counts to optimize. run_job_id: Run job whose stored results supply ``counts``. params: Optional post-processing parameter overrides. max_solutions: Cap on how many solutions are returned inline. examples: - lp_problem: |- Minimize obj: x0 + x1 Binary x0 x1 End params: postprocess_iterations: 10 seed: 42 run_job_id: jb-abc123 - counts: '00': 100 '01': 50 lp_problem: |- Minimize obj: x0 + x1 Binary x0 x1 End max_solutions: 5 ContextPostprocessResultModel: properties: best_bitstring: anyOf: - type: string - type: 'null' title: Best Bitstring best_cost: anyOf: - type: number - type: 'null' title: Best Cost solutions: items: additionalProperties: true type: object type: array title: Solutions returned_solutions: type: integer title: Returned Solutions total_solutions: type: integer title: Total Solutions truncated: type: boolean title: Truncated context: type: string title: Context type: object required: - solutions - returned_solutions - total_solutions - truncated - context title: ContextPostprocessResultModel description: |- Represent post-processed QUBO solutions, truncated for tool output. Attributes: best_bitstring: Lowest-cost solution found. best_cost: Objective value of ``best_bitstring``. solutions: Best solutions as ``bitstring`` / ``cost`` / ``count`` entries, ordered by cost. returned_solutions: Number of entries in ``solutions``. total_solutions: Number of solutions the post-processor produced. truncated: Whether ``solutions`` omits some results. context: Summary of the outcome and how to read it. HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError securitySchemes: APIKeyQuery: type: apiKey in: query name: HAIQU_API_KEY APIKeyHeader: type: apiKey in: header name: authorization ````