feat: send cc, bcc and attachments with emails.send by Silthus · Pull Request #1172 · PostHog/posthog-python

Silthus · 2026-11-03T08:13:45Z

💡 Motivation and Context

Problem: an app moving its email from Resend to PostHog can't send a receipt with a PDF, or copy finance on an invoice. posthog.emails.send takes rendered html/text only (#1171).

Change: the code form takes cc, bcc and attachments, as the send contract defines them.

cc/bcc: one address or a list. A string becomes a one-item list on the wire.
An empty cc, bcc or attachments list is left out, as feat: send email content from code with posthog.emails.send #1171 does for reply_to, so an older server still sends the email.
attachments: {filename, content, content_type?, content_id?}. Bytes are Base64-encoded once, before the retry loop. A string is sent as is.
A path key (Resend style), an unknown key, a missing or empty filename, or content that isn't bytes or a Base64 string raises invalid_attachment with a field such as attachments__0__content. The error never repeats the content.
With template_id, all three fields are refused before any request.
The server holds the limits (10 addresses, 10 files, 512 KB). A server without these fields refuses the send with an error naming the field, and never drops them.

Stacked on #1171. It mirrors posthog-node in PostHog/posthog-js#5514.

Impact: Grow Workflows. It removes a blocker for Resend migrations, seen as code sends with migrated_from in project 2.

Merge danger: low, two-way door. The fields are new and optional in an unreleased API. Release this only after the server half deploys; until then a send with these fields gets 400.

💚 How did you test it?

Proof gate passes at ac102e0: CI green, review clean, and both owed proofs captured.
StampHog can't approve this PR: its policy sends any public API addition to a human maintainer.
Test seams: the request body emails.send posts (bytes become Base64, content_type/content_id mapped), the refusals on the template form, and the invalid_attachment cases. The sync and async clients are both covered.
Live run: a send with to, two cc, one bcc, a binary PDF and an inline PNG went through a local PostHog with the server stack (feat(cdp): deliver transactional email attachments from a side table posthog#127986, #127988) to maildev. The files arrived byte-identical, the PNG inline, and the bcc only in the envelope.
Cross-version: against today's server (feat(messaging): send an email with inline html from code posthog#127123), a send with these fields gets a 400 naming attachments and nothing is sent. A plain send still delivers.

📝 Checklist

All commits are signed (see Commit signing)
I reviewed the submitted code.
I added tests to verify the changes.
I updated the docs if needed.
No breaking change or entry added to the changelog.

If releasing new changes

Ran sampo add to generate a changeset file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Written by Claude Opus 5.5 (claude-opus-5-5) in Claude Code, for Michael. The fields come back from the pre-cut code of #1171 (e654aef), without headers, tags or local templates.

Question	Answer	Who	Where
Which code-form fields ship in the attachments slice?	Attachments, cc and bcc. Headers and tags wait for a later slice	👍 Accepted default	comment
How does StampHog approve an SDK draft?	Mark it ready for the stamp, then back to draft	👍 Accepted default	comment

Involvement: 2 questions answered. Reviews: GPT-6.1 Sol and Opus 5.5, rounds 1 and 2 and five final reads; StampHog. Proof captured: live run and cross-version.

🤖 Generated with Claude Code

Squash of Silthus#2 at e5fdedf, re-signed for required signatures. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Takes the flat send body from #1155, and sends a flat distinct_id from the local-template form too. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Parks the local-template form (template_data on a code send, the content hash, the upload by key and its retry) and the cc, bcc, headers, tags and attachments fields, to match posthog-node. A code send now takes rendered html and/or text only. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

A code send takes cc and bcc as one address or a list, and attachments as files with bytes or Base64 content. The client encodes bytes once, before any retry. A file it can't send raises EmailError with the code invalid_attachment and a field such as attachments__0__content, and the error never repeats the file's content. A template_id send refuses all three fields before any request. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Silthus · 2026-11-03T08:14:43Z

Note

🤖 Claude Opus 5.5 writing on behalf of Michael

Decisions for the attachments slice:

👍 Which code-form fields ship in the attachments slice? Attachments, cc and bcc. Headers and tags wait for a later slice.
👍 How does StampHog approve an SDK draft? StampHog doesn't review drafts, so this PR goes ready only for the stamp, then back to draft.

github-actions · 2026-11-03T08:16:47Z

posthog-python Compliance Report

Date: 2026-11-06T07:52:50.939186+00:00
Duration: 259610ms

✅ All Tests Passed!

121/121 tests passed

Capture_V1 Tests

✅ 95/95 tests passed

View Details

Test	Status	Duration
Endpoint And Method.Targets V1 Endpoint	✅	518ms
Endpoint And Method.Does Not Use Legacy Endpoints	✅	509ms
Required Headers.Has Authorization Bearer Header	✅	509ms
Required Headers.Has Content Type Json	✅	509ms
Required Headers.Has Posthog Sdk Info Format	✅	508ms
Required Headers.Has Posthog Attempt Header	✅	510ms
Required Headers.Has Posthog Request Id	✅	508ms
Required Headers.Has Posthog Request Timestamp	✅	509ms
Required Headers.Has User Agent	✅	509ms
Body Format.Body Has Created At And Batch	✅	509ms
Body Format.No Api Key In Body	✅	509ms
Body Format.No Sent At In Body	✅	508ms
Event Format.Event Has Required Root Fields	✅	509ms
Event Format.Event Uuid Is Valid	✅	509ms
Event Format.Event Timestamp Is Rfc3339	✅	509ms
Event Format.Non Utc Event Timestamp Is Converted To Utc	✅	523ms
Event Format.Distinct Id Is String	✅	509ms
Event Format.Distinct Id At Root Not Properties	✅	509ms
Event Format.Custom Properties Preserved	✅	509ms
Event Format.Set Properties Preserved	✅	508ms
Event Format.Set Once Properties Preserved	✅	509ms
Event Format.Groups Properties Preserved	✅	509ms
Event Format.Sdk Generates Uuid If Not Provided	✅	509ms
Event Format.Event Has Required Root Fields Batch	✅	512ms
Event Format.Event Uuid Is Valid Batch	✅	511ms
Event Format.Event Timestamp Is Rfc3339 Batch	✅	512ms
Event Format.Distinct Id Is String Batch	✅	511ms
Event Format.Distinct Id At Root Not Properties Batch	✅	513ms
Event Format.Custom Properties Preserved Batch	✅	511ms
Event Format.Set Properties Preserved Batch	✅	511ms
Event Format.Set Once Properties Preserved Batch	✅	512ms
Event Format.Groups Properties Preserved Batch	✅	512ms
Event Format.Sdk Generates Uuid If Not Provided Batch	✅	511ms
Batch Behavior.Multiple Events In Single Batch	✅	515ms
Batch Behavior.Batch Envelope Smoke	✅	512ms
Batch Behavior.Flush With No Events Sends Nothing	✅	506ms
Batch Behavior.Flush At Triggers Batch	✅	1010ms
Batch Behavior.Created At Reflects Batch Creation Time	✅	509ms
Deduplication.Generates Unique Uuids	✅	515ms
Deduplication.Different Events Same Content Different Uuids	✅	510ms
Deduplication.Preserves Uuid On Retry	✅	6517ms
Deduplication.Preserves Timestamp On Retry	✅	6518ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	6520ms
Deduplication.No Duplicate Events In Batch	✅	515ms
Header Behavior On Retry.Attempt Header Starts At One	✅	509ms
Header Behavior On Retry.Attempt Header Increments On Retry	✅	13524ms
Header Behavior On Retry.Request Id Preserved On Retry	✅	6518ms
Header Behavior On Retry.Different Requests Have Different Request Ids	✅	3017ms
Header Behavior On Retry.Request Timestamp Changes On Retry	✅	6518ms
Response Format Validation.Success Response Has Uuid Keyed Results	✅	509ms
Response Format Validation.Success Response Has Ok For Each Event	✅	512ms
Response Format Validation.Success No Retry After When All Ok	✅	511ms
Response Format Validation.Success Retry After Present When Retry Events	✅	1513ms
Response Format Validation.Success No Retry After When Drop Only	✅	511ms
Response Format Validation.Response Echoes Request Id	✅	509ms
Retry Behavior.Retries On 408	✅	6517ms
Retry Behavior.Retries On 500	✅	6517ms
Retry Behavior.Retries On 503	✅	8521ms
Retry Behavior.Retries On 504	✅	6513ms
Retry Behavior.Retryable Errors Have Retry After	✅	3514ms
Retry Behavior.Respects Retry After On Retryable Error	✅	11519ms
Retry Behavior.Does Not Retry On 400	✅	2512ms
Retry Behavior.Does Not Retry On 401	✅	2512ms
Retry Behavior.Does Not Retry On 402	✅	2511ms
Retry Behavior.Does Not Retry On 413	✅	2512ms
Retry Behavior.Does Not Retry On 415	✅	2512ms
Retry Behavior.Non Retryable Errors Have No Retry After	✅	2512ms
Retry Behavior.Implements Backoff	✅	22534ms
Retry Behavior.Max Retries Respected	✅	22533ms
Partial Batch Handling.Handles 200 Full Success	✅	2510ms
Partial Batch Handling.Handles 200 With All Ok	✅	3516ms
Partial Batch Handling.Does Not Retry Dropped Events	✅	3515ms
Partial Batch Handling.Does Not Retry Limited Events	✅	3513ms
Partial Batch Handling.Prunes Ok Events On Partial Retry	✅	6519ms
Partial Batch Handling.Prunes Dropped Events On Partial Retry	✅	6518ms
Partial Batch Handling.Retries Only Retry Events From Partial	✅	6521ms
Partial Batch Handling.Partial Retry Preserves Uuids	✅	6519ms
Partial Batch Handling.Partial Retry Attempt Header Increments	✅	6518ms
Partial Batch Handling.Partial Retry Request Id Preserved	✅	6518ms
Partial Batch Handling.Respects Retry After On Partial	✅	8516ms
Partial Batch Handling.Unknown Result Treated As Terminal	✅	3515ms
Partial Batch Handling.Mixed Ok Drop Limited No Retry	✅	3514ms
Compression.Sends Gzip Content Encoding	✅	509ms
Compression.No Content Encoding When Disabled	✅	508ms
Compression.Compressed Body Is Decompressible	✅	508ms
Error Handling.Does Not Retry On Unknown 4Xx	✅	2511ms
Event Options.Cookieless Mode Override	✅	509ms
Event Options.Disable Skew Correction Override	✅	508ms
Event Options.Process Person Profile Override	✅	509ms
Event Options.Product Tour Id Override	✅	509ms
Event Options.Unset Options Omitted	✅	508ms
Event Options.Options Override In Batch	✅	511ms
Geoip And Historical Migration.Geoip Disable Injected Into Properties	✅	508ms
Geoip And Historical Migration.Historical Migration Set In Body	✅	508ms
Geoip And Historical Migration.Historical Migration Absent By Default	✅	509ms

Capture_Ai Tests

✅ 5/5 tests passed

View Details

Test	Status	Duration
Routing.Capture Ai Posts To Ai Endpoint	✅	508ms
Routing.Capture Does Not Reroute Ai Named Events	✅	509ms
Identity.Capture Ai Event Has Uuid	✅	510ms
Identity.Capture Ai Keeps Supplied Uuid	✅	508ms
Timestamp Format.Non Utc Event Timestamp Is Converted To Utc	✅	508ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	10ms
Request Payload.Flags Request Uses V4 Query Param	✅	7ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	7ms
Request Payload.Flags Request Omits Authorization Header	✅	7ms
Request Payload.Token In Flags Body Matches Init	✅	7ms
Request Payload.Groups Round Trip	✅	8ms
Request Payload.Groups Default To Empty Object	✅	7ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	7ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	7ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	7ms
Request Lifecycle.No Flags Request On Init Alone	✅	3ms
Request Lifecycle.No Flags Request On Normal Capture	✅	508ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	11ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	7ms
Retry Behavior.Retries Flags On 502	✅	311ms
Retry Behavior.Retries Flags On 504	✅	310ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	510ms

Feature_Flags_Local_Evaluation Tests

✅ 4/4 tests passed

View Details

Test	Status	Duration
Versioned Boolean Matching.Matching Version Missing	✅	54ms
Versioned Boolean Matching.Matching Version 1	✅	52ms
Versioned Boolean Matching.Matching Version 2	✅	53ms
Versioned Boolean Matching.Version Only Reload 1 2 1 2 Missing	✅	27ms

next(..., None) used None as its no-match value, so a None key hid the unknown keys after it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

stamphog

Not approved — this change needs a human reviewer.

Re-adding the stamphog label gives the same result unless the changed files change.

StampHog can't approve this pull request automatically. Two gates refused it. The deny-list gate flagged a public API change: posthog/emails.py adds the EmailAttachment type and new cc, bcc and attachments fields on CodeEmailArgs, and references/public_api_snapshot.txt records them. The tier gate classified the change as T2-never (336 lines across 5 files, cross-cutting, a feature), a tier that is never auto-approved.

The size gate passed, so splitting the pull request won't change the outcome. Ask a human maintainer to review it, since a public API addition needs that sign-off.

Gate mechanics and policy version

Gate		Result
prerequisites	✓	all clear
deny-list	✗	matches: public_api
size	✓	124L, 2F substantive, 336L/5F incl. docs/generated/snapshots — within ceiling
tier	✗	classified as T2-never: T2-never (336L, 5F, cross-cutting, feat)
stamphog 2.7.0		`.stamphog/policy.yml` @ `unknown` · reviewed head `a080862`

veria-ai · 2026-11-03T10:34:52Z

+        attachments, (str, bytes, bytearray, memoryview, Mapping)
+    ) or not isinstance(attachments, Sequence):
+        raise _invalid_attachment("attachments must be a list of files.", "attachments")
+    return [_attachment(index, file) for index, file in enumerate(attachments)]


Medium: Bound attachments before encoding

The documented 10-file/512 KB limits are not checked before this comprehension encodes every attachment and _encode materializes the JSON body; an isolated preparation check accepted an 8 MiB file and allocated roughly 32 MiB beyond the original input. As defense in depth for applications forwarding user uploads, check file count and aggregate size before encoding, including bounds for Base64 strings, since server-side rejection cannot protect the host process from these allocations.

Not changing this. The server owns the 10-file and 512 KB limits, so it can raise them without a new SDK release. A copy of the limits here would drift. The caller already holds the file in memory, and Base64 adds a third to its size. That cost is the caller's choice, and the server refuses the send before anything goes out.

veria-ai · 2026-11-03T10:34:58Z

PR overview

The PR extends emails.send to support CC and BCC recipients and email attachments, including encoding attachments for the request body.

One issue remains open: attachment count and size limits are not enforced before encoding and JSON serialization, allowing oversized inputs to cause substantial memory allocations in the calling application. This is a defense-in-depth gap for applications forwarding user uploads, since server-side rejection occurs too late to prevent those local allocations. No issues have been addressed yet.

Open issues (1)

Medium: Bound attachments before encoding — posthog/emails.py:456

Fixed/addressed: 0 · PR risk: 4/10

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…/emails-code-attachments # Conflicts: # posthog/emails.py # posthog/test/test_emails.py

A text file passed as a str was sent unchecked as if it were Base64. The client now raises invalid_attachment before any request and hints to pass the file's bytes instead. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

The base PR owns emails-code-form.md, so this PR no longer edits it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…chments # Conflicts: # .github/scripts/check_strict_types.sh # posthog/emails.py # posthog/test/test_emails.py # references/public_api_snapshot.txt

github-actions · 2026-11-06T07:54:27Z

SDK performance: posthog-python

Benchmarks completed. No changes flagged for review.

Flags require at least a 5% change in the median and all six pairs agreeing on direction. This is a noise filter, not proof of a performance change or a CI gate.

View all results

Test	Measurement	Before PR	With PR	Change	Assessment
Capture and deliver events (32-byte payload, burst) Shard: capture	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Capture and deliver events (32-byte payload, steady) Shard: capture	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Queue an event (32-byte payload) Shard: capture	Allocated memory per operation	—	—	—	unavailable; base: unsupported; head: unsupported; base: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.; head: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.
Queue an event (32-byte payload) Shard: capture	Allocations per operation	—	—	—	unavailable; base: unsupported; head: unsupported; base: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.; head: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.
Queue an event (4,096-byte payload) Shard: capture	Allocated memory per operation	—	—	—	unavailable; base: unsupported; head: unsupported; base: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.; head: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.
Queue an event (4,096-byte payload) Shard: capture	Allocations per operation	—	—	—	unavailable; base: unsupported; head: unsupported; base: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.; head: Background preparation has no public completion boundary before flush; see capture.drain for full-pipeline allocations.
Evaluate 1,000 flags under concurrent load Shard: flags-memory	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Refresh 1,000 flag definitions Shard: flags-memory	Managed heap after settling	—	—	—	unavailable; base: unsupported; head: unsupported; base: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.; head: CPython has no uninstrumented total managed-heap byte counter; tracing would distort this RSS pass.
Capture and deliver events (32-byte payload, burst) Shard: capture	Allocated memory per operation	113.54 KiB/op	113.54 KiB/op	<0.1% less memory	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Allocations per operation	1,096.62 count/op	1,096.6 count/op	<0.1% fewer	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Time per operation	76.35 µs/op	69.7 µs/op	8.7% less time	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Idle process memory (RSS)	35.99 MiB	35.94 MiB	0.1% less memory	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Observed peak process memory (RSS)	37.75 MiB	37.67 MiB	0.2% less memory	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Process memory after settling (RSS)	37.75 MiB	37.67 MiB	0.2% less memory	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Process CPU time per operation	77.58 µs/op	69.79 µs/op	10% less time	Not flagged
Capture and deliver events (32-byte payload, burst) Shard: capture	Lifetime peak process memory (RSS)	40.34 MiB	40.34 MiB	No observed change	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Allocated memory per operation	166.1 KiB/op	166.1 KiB/op	<0.1% more memory	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Allocations per operation	1,089.57 count/op	1,089.58 count/op	<0.1% more	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Time per operation	100.99 µs/op	105.12 µs/op	4.1% more time	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Idle process memory (RSS)	40.88 MiB	40.83 MiB	0.1% less memory	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Observed peak process memory (RSS)	45.97 MiB	45.91 MiB	0.1% less memory	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Process memory after settling (RSS)	45.97 MiB	45.91 MiB	0.1% less memory	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Process CPU time per operation	93.14 µs/op	96.13 µs/op	3.2% more time	Not flagged
Capture and deliver events (4,096-byte payload, burst) Shard: capture	Lifetime peak process memory (RSS)	50.7 MiB	50.78 MiB	0.2% more memory	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Allocated memory per operation	117.68 KiB/op	117.68 KiB/op	<0.1% more memory	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Allocations per operation	1,136.56 count/op	1,136.58 count/op	<0.1% more	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Time per operation	86.64 µs/op	85.58 µs/op	1.2% less time	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Idle process memory (RSS)	35.95 MiB	36 MiB	0.1% more memory	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Observed peak process memory (RSS)	36.05 MiB	36.1 MiB	0.1% more memory	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Process memory after settling (RSS)	36.05 MiB	36.1 MiB	0.1% more memory	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Process CPU time per operation	82.67 µs/op	81.61 µs/op	1.3% less time	Not flagged
Capture and deliver events (32-byte payload, steady) Shard: capture	Lifetime peak process memory (RSS)	40.34 MiB	40.34 MiB	No observed change	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Allocated memory per operation	170.57 KiB/op	170.57 KiB/op	<0.1% more memory	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Allocations per operation	1,129.48 count/op	1,129.49 count/op	<0.1% more	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Time per operation	109.72 µs/op	115.37 µs/op	5.1% more time	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Idle process memory (RSS)	40.7 MiB	40.75 MiB	0.1% more memory	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Observed peak process memory (RSS)	40.7 MiB	40.76 MiB	0.1% more memory	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Process memory after settling (RSS)	40.7 MiB	40.76 MiB	0.1% more memory	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Process CPU time per operation	101.56 µs/op	107.73 µs/op	6.1% more time	Not flagged
Capture and deliver events (4,096-byte payload, steady) Shard: capture	Lifetime peak process memory (RSS)	41 MiB	41.01 MiB	<0.1% more memory	Not flagged
Queue an event (32-byte payload) Shard: capture	Caller-thread CPU time per operation	50.74 µs/op	51.31 µs/op	1.1% more time	Not flagged
Queue an event (32-byte payload) Shard: capture	Time per operation	57.19 µs/op	57.97 µs/op	1.4% more time	Not flagged
Queue an event (4,096-byte payload) Shard: capture	Caller-thread CPU time per operation	52.28 µs/op	47.37 µs/op	9.4% less time	Not flagged
Queue an event (4,096-byte payload) Shard: capture	Time per operation	60.6 µs/op	55.63 µs/op	8.2% less time	Not flagged
Evaluate all 10 flags Shard: flags-scaling	Allocated memory per operation	200.98 KiB/op	200.98 KiB/op	No observed change	Not flagged
Evaluate all 10 flags Shard: flags-scaling	Allocations per operation	2,339.33 count/op	2,339.33 count/op	No observed change	Not flagged
Evaluate all 10 flags Shard: flags-scaling	Time per operation	131.18 µs/op	131.64 µs/op	0.4% more time	Not flagged
Evaluate all 10 flags Shard: flags-scaling	Process CPU time per operation	131.18 µs/op	131.64 µs/op	0.4% more time	Not flagged
Evaluate all 100 flags Shard: flags-scaling	Allocated memory per operation	1.93 MiB/op	1.93 MiB/op	No observed change	Not flagged
Evaluate all 100 flags Shard: flags-scaling	Allocations per operation	23,013.56 count/op	23,013.56 count/op	No observed change	Not flagged
Evaluate all 100 flags Shard: flags-scaling	Time per operation	1.25 ms/op	1.24 ms/op	0.2% less time	Not flagged
Evaluate all 100 flags Shard: flags-scaling	Process CPU time per operation	1.25 ms/op	1.24 ms/op	0.2% less time	Not flagged
Evaluate all 1,000 flags Shard: flags-scaling	Allocated memory per operation	19.24 MiB/op	19.24 MiB/op	No observed change	Not flagged
Evaluate all 1,000 flags Shard: flags-scaling	Allocations per operation	229,654.94 count/op	229,654.94 count/op	No observed change	Not flagged
Evaluate all 1,000 flags Shard: flags-scaling	Time per operation	12.75 ms/op	12.71 ms/op	0.3% less time	Not flagged
Evaluate all 1,000 flags Shard: flags-scaling	Process CPU time per operation	12.75 ms/op	12.71 ms/op	0.3% less time	Not flagged
Evaluate 1,000 flags under concurrent load Shard: flags-memory	Idle process memory (RSS)	41.71 MiB	42.27 MiB	1.3% more memory	Not flagged
Evaluate 1,000 flags under concurrent load Shard: flags-memory	Observed peak process memory (RSS)	41.97 MiB	42.56 MiB	1.4% more memory	Not flagged
Evaluate 1,000 flags under concurrent load Shard: flags-memory	Process memory after settling (RSS)	41.97 MiB	42.56 MiB	1.4% more memory	Not flagged
Evaluate 1,000 flags under concurrent load Shard: flags-memory	Lifetime peak process memory (RSS)	42.51 MiB	42.44 MiB	0.2% less memory	Not flagged
Refresh 1,000 flag definitions Shard: flags-memory	Idle process memory (RSS)	42.12 MiB	41.46 MiB	1.6% less memory	Not flagged
Refresh 1,000 flag definitions Shard: flags-memory	Observed peak process memory (RSS)	42.19 MiB	42.11 MiB	0.2% less memory	Not flagged
Refresh 1,000 flag definitions Shard: flags-memory	Process memory after settling (RSS)	42.18 MiB	42.09 MiB	0.2% less memory	Not flagged
Refresh 1,000 flag definitions Shard: flags-memory	Lifetime peak process memory (RSS)	42.58 MiB	42.48 MiB	0.2% less memory	Not flagged
Evaluate one boolean flag Shard: flags-single	Allocated memory per operation	15.05 KiB/op	15.05 KiB/op	No observed change	Not flagged
Evaluate one boolean flag Shard: flags-single	Allocations per operation	173.76 count/op	173.76 count/op	No observed change	Not flagged
Evaluate one boolean flag Shard: flags-single	Time per operation	14.05 µs/op	14.02 µs/op	0.2% less time	Not flagged
Evaluate one boolean flag Shard: flags-single	Process CPU time per operation	14.05 µs/op	14.02 µs/op	0.2% less time	Not flagged
Evaluate a cohort-filtered flag Shard: flags-single	Allocated memory per operation	23.12 KiB/op	23.12 KiB/op	No observed change	Not flagged
Evaluate a cohort-filtered flag Shard: flags-single	Allocations per operation	270.27 count/op	270.27 count/op	No observed change	Not flagged
Evaluate a cohort-filtered flag Shard: flags-single	Time per operation	21.94 µs/op	21.8 µs/op	0.7% less time	Not flagged
Evaluate a cohort-filtered flag Shard: flags-single	Process CPU time per operation	21.94 µs/op	21.79 µs/op	0.7% less time	Not flagged
Evaluate a flag (early match) Shard: flags-single	Allocated memory per operation	35.71 KiB/op	35.71 KiB/op	No observed change	Not flagged
Evaluate a flag (early match) Shard: flags-single	Allocations per operation	387.27 count/op	387.27 count/op	No observed change	Not flagged
Evaluate a flag (early match) Shard: flags-single	Time per operation	27.44 µs/op	27.49 µs/op	0.2% more time	Not flagged
Evaluate a flag (early match) Shard: flags-single	Process CPU time per operation	27.44 µs/op	27.49 µs/op	0.2% more time	Not flagged
Evaluate a flag (late match) Shard: flags-single	Allocated memory per operation	53.59 KiB/op	53.59 KiB/op	No observed change	Not flagged
Evaluate a flag (late match) Shard: flags-single	Allocations per operation	576.27 count/op	576.27 count/op	No observed change	Not flagged
Evaluate a flag (late match) Shard: flags-single	Time per operation	38.18 µs/op	38.3 µs/op	0.3% more time	Not flagged
Evaluate a flag (late match) Shard: flags-single	Process CPU time per operation	38.18 µs/op	38.3 µs/op	0.3% more time	Not flagged
Evaluate a flag (no match) Shard: flags-single	Allocated memory per operation	52.14 KiB/op	52.14 KiB/op	No observed change	Not flagged
Evaluate a flag (no match) Shard: flags-single	Allocations per operation	556.77 count/op	556.77 count/op	No observed change	Not flagged
Evaluate a flag (no match) Shard: flags-single	Time per operation	34.82 µs/op	34.7 µs/op	0.3% less time	Not flagged
Evaluate a flag (no match) Shard: flags-single	Process CPU time per operation	34.81 µs/op	34.69 µs/op	0.3% less time	Not flagged
Evaluate a property-filtered flag Shard: flags-single	Allocated memory per operation	17.84 KiB/op	17.84 KiB/op	No observed change	Not flagged
Evaluate a property-filtered flag Shard: flags-single	Allocations per operation	198.27 count/op	198.27 count/op	No observed change	Not flagged
Evaluate a property-filtered flag Shard: flags-single	Time per operation	16.6 µs/op	16.52 µs/op	0.5% less time	Not flagged
Evaluate a property-filtered flag Shard: flags-single	Process CPU time per operation	16.6 µs/op	16.52 µs/op	0.5% less time	Not flagged
Evaluate a regex-filtered flag Shard: flags-single	Allocated memory per operation	19.23 KiB/op	19.23 KiB/op	No observed change	Not flagged
Evaluate a regex-filtered flag Shard: flags-single	Allocations per operation	210.77 count/op	210.77 count/op	No observed change	Not flagged
Evaluate a regex-filtered flag Shard: flags-single	Time per operation	17.48 µs/op	17.55 µs/op	0.4% more time	Not flagged
Evaluate a regex-filtered flag Shard: flags-single	Process CPU time per operation	17.48 µs/op	17.55 µs/op	0.4% more time	Not flagged
Evaluate a rollout flag Shard: flags-single	Allocated memory per operation	14.04 KiB/op	14.04 KiB/op	No observed change	Not flagged
Evaluate a rollout flag Shard: flags-single	Allocations per operation	160.76 count/op	160.76 count/op	No observed change	Not flagged
Evaluate a rollout flag Shard: flags-single	Time per operation	12.98 µs/op	13.05 µs/op	0.5% more time	Not flagged
Evaluate a rollout flag Shard: flags-single	Process CPU time per operation	12.98 µs/op	13.05 µs/op	0.5% more time	Not flagged
Evaluate a multivariate flag Shard: flags-single	Allocated memory per operation	15.21 KiB/op	15.21 KiB/op	No observed change	Not flagged
Evaluate a multivariate flag Shard: flags-single	Allocations per operation	177.77 count/op	177.77 count/op	No observed change	Not flagged
Evaluate a multivariate flag Shard: flags-single	Time per operation	14.59 µs/op	14.55 µs/op	0.3% less time	Not flagged
Evaluate a multivariate flag Shard: flags-single	Process CPU time per operation	14.59 µs/op	14.55 µs/op	0.3% less time	Not flagged

Values are medians of paired measurements. Not flagged does not mean unchanged. Unavailable means a measurement could not be provided, not zero. Estimated allocation measurements retain their instrumentation uncertainty. RSS measures the whole process, not just SDK allocations; observed peaks are sampled checkpoints. Paired ranges in the diagnostics describe variability, not confidence intervals.

Each shard uses its own runner; compare Before PR against With PR within a row, not across shards.

Compared 6b7c0ba3e72b8ebdc3b1f65aedafbb44c7c67256 → 860b42f581b6f2bd42a5951452e7990133ed3b97.

Full report and diagnostics

102 metric rows; 102 rows shown in all results. Omitted or shortened data remain in comparison.json, including per-runner environments, resource limits, measurement methods, samples and checkpoints.

Silthus and others added 5 commits November 2, 2026 10:21

feat: send email content from code with posthog.emails.send

625f373

Squash of Silthus#2 at e5fdedf, re-signed for required signatures. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Merge branch 'main' into feat/emails-code-form

e654aef

Takes the flat send body from #1155, and sends a flat distinct_id from the local-template form too. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test(emails): cover the async code-form send and migrated_from

9a4dd48

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Silthus self-assigned this Nov 3, 2026

Silthus mentioned this pull request Nov 3, 2026

feat(node): send cc, bcc and attachments from code PostHog/posthog-js#5514

Open

7 of 24 tasks

Silthus and others added 3 commits November 3, 2026 08:18

fix: refuse every unknown attachment key, a None key included

f906fb3

next(..., None) used None as its no-match value, so a None key hid the unknown keys after it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test: cover a None attachment key before an unknown one

bf687be

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs: describe an older server's refusal without its error code

a080862

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Silthus marked this pull request as ready for review November 3, 2026 10:32

Silthus requested a review from a team as a code owner November 3, 2026 10:32

stamphog Bot reviewed Nov 3, 2026

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Silthus marked this pull request as draft November 3, 2026 10:40

Silthus and others added 2 commits November 3, 2026 10:42

fix(emails): leave reply_to out when the list is empty

b93ea5c

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Merge remote-tracking branch 'origin/feat/emails-code-form' into feat…

4a7c6df

…/emails-code-attachments # Conflicts: # posthog/emails.py # posthog/test/test_emails.py

Silthus and others added 4 commits November 4, 2026 08:00

chore(emails): name the refused-send test after what it guards

8e58646

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

chore(emails): drop a comment the name and test already state

1b7fd90

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

chore(emails): give cc, bcc and attachments their own changeset

f5d6f0a

The base PR owns emails-code-form.md, so this PR no longer edits it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

fix(emails): refuse an attachment with an empty filename

ac102e0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Silthus marked this pull request as ready for review November 4, 2026 10:12

Silthus changed the base branch from feat/emails-code-form to main November 5, 2026 12:09

This was referenced Nov 5, 2026

docs(workflows): send transactional emails from Go, .NET, Rust, Ruby, Elixir and PHP PostHog/posthog.com#21932

Merged

docs(workflows): send copies and attachments from every SDK PostHog/posthog.com#22022

Draft

Merge remote-tracking branch 'origin/main' into feat/emails-code-atta…

860b42f

…chments # Conflicts: # .github/scripts/check_strict_types.sh # posthog/emails.py # posthog/test/test_emails.py # references/public_api_snapshot.txt

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feat: send cc, bcc and attachments with emails.send - #1172

feat: send cc, bcc and attachments with emails.send#1172
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💡 Motivation and Context

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posthog-python Compliance Report

✅ All Tests Passed!

Capture_V1 Tests

Capture_Ai Tests

Feature_Flags Tests

Feature_Flags_Local_Evaluation Tests

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veria-ai Bot commented Nov 3, 2026

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SDK performance: posthog-python

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