Add endpoint for returning connection probabilities

[chr-pok]

Description:
An endpoint should be added that returns the connection probabilities between groups of neurons in a given circuit, optionally grouped by a certain node property.

Specifications from ExploreCircuitQuestions.xlsx:

• Input:
  • Any number of pairs of: node property name + list of valid values
  • Node property name for grouping (optional)
  • Maximum distance (optional)
  • Type of connectivity (optional) ??
• Output:
  • DataFrame with three columns: pre-type (str), post-type (str), connection probability (float)

Acceptance criterion:
Endpoint implemented, tested, and PR merged.

[chr-pok]

Worked on in the obi-one branch conn_prob_endpoint.

[chr-pok]

Status update:

• Implemented partial circuit download (required components only)
• Implemented connectivity computation (using connectome-manipulator)
• Added declared endpoint (w/o input dicts)
• Added example notebook

Notes:

• Currently returns two connectivity metrics: connection probability and mean number of synapses per connection
• Valid edge population and property names/values for node selection and grouping need to be known (can be retrieved using the circuit metrics endpoint)
• Small changes in connectme-manipulator required to properly handle some edge cases

[chr-pok]

Agreed on in today's AI meeting:

• Providing pre-/post-synaptic selection dictionaries through a POST endpoint
• AI agent is responsible for querying valid edge population names and group-by properties before calling this endpoint

[chr-pok]

PR#378 in obi-one has been created.

Another PR#4 in connectome-manipulator is in preparation to properly handle the following special cases:

• Adding support for group-by to be empty, in which case no grouping will be applied (returning just a single value)
• Adding support for ignoring group-by in case the grouping property does not exist in one of the pre- or post-synaptic node population (e.g., virtual populations), in which case the grouping will only be applied to the population where it does exist (but it will still raise an error if the grouping property does not exist in either of the populations)

[evakennyobi]

@james-isbister to check
make dependencies optional (separate ticket?)

[evakennyobi]

api error code, put something general

[chr-pok]

@james-isbister to check make dependencies optional (separate ticket?)

Created a separate ticket here: #401

[chr-pok]

api error code, put something general

Error codes have been fixed by introducing an INTERNAL_ERROR type.

[chr-pok]

PR#378 has been approved and merged into main. A new obi-one release is in preparation in agreement with @james-isbister.

[chr-pok]

A new obi-one release 2025.10.1 including the connectivity metrics endpoint is ready. A version bump PR#638 in AWS terraform has been created.

FYI @jankrepl, @jdcourcol