feat(infra): convert sh-openswe-traces to HCP Terraform

Freeze SAM CD and add terraform/ for seahaven-prod with account-suffixed buckets so HCP owns deploy before mgmt cutover. Suppress CKV_AWS_40 for the LangSmith export IAM user with documented mitigations.
2026-09-30 08:03:18 +00:00 · 2026-08-05 18:28:44 -04:00 · 2026-08-05 18:28:44 -04:00 · 56de409dea
commit 56de409dea
parent 50ac3de884
16 changed files with 533 additions and 53 deletions
--- a/.github/workflows/deploy.yaml
+++ b/.github/workflows/deploy.yaml
@ -1,7 +1,14 @@
+# FROZEN for PLAT-73: HCP Terraform is the sole deploy path.
+# Previous SAM CD preserved as deploy.yaml.frozen until mgmt cutover.
+# Do not re-enable until the migration is rolled back intentionally.
 name: Deploy
 on:
-  push:
-    branches: [main]
+  workflow_dispatch:
+    inputs:
+      confirm_unfreeze:
+        description: "Type UNFREEZE to acknowledge this bypasses PLAT-73 freeze"
+        required: true
+        type: string

 permissions:
  id-token: write
@ -13,6 +20,7 @@ concurrency:

 jobs:
  deploy:
+    if: ${{ inputs.confirm_unfreeze == 'UNFREEZE' }}
    uses: Sea-Haven-Industries/.github/.github/workflows/cd-sam.yaml@3f746774229d41770727e2e4fd63ed5f5555a8b3 # v1.0.3
    with:
      stack-name: sh-openswe-traces
--- a/.github/workflows/deploy.yaml.frozen
+++ b/.github/workflows/deploy.yaml.frozen
@ -0,0 +1,22 @@
+name: Deploy
+on:
+  push:
+    branches: [main]
+
+permissions:
+  id-token: write
+  contents: read
+
+concurrency:
+  group: deploy
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    uses: Sea-Haven-Industries/.github/.github/workflows/cd-sam.yaml@3f746774229d41770727e2e4fd63ed5f5555a8b3 # v1.0.3
+    with:
+      stack-name: sh-openswe-traces
+      cfn-role-arn: arn:aws:iam::328440206208:role/sh-openswe-traces-cfn-exec-role
+    secrets:
+      deploy-role-arn: ${{ secrets.AWS_DEPLOY_ROLE_ARN }}
+      parameter-overrides: ${{ secrets.SAM_PARAMETER_OVERRIDES }}
--- a/.gitignore
+++ b/.gitignore
@ -5,3 +5,14 @@ samconfig.toml
 *.pyc
 __pycache__/
 .DS_Store
+# Local Terraform
+terraform/.terraform/
+*.tfstate
+*.tfstate.*
+crash.log
+override.tf
+override.tf.json
+*_override.tf
+*_override.tf.json
+.terraformrc
+terraform.rc
--- a/.security-review/suppressions.json
+++ b/.security-review/suppressions.json
@ -6,7 +6,11 @@
    },
    {
      "id": "checkov-CKV_AWS_111-13",
-      "justification": "False positive. Same ExecRole. CKV_AWS_111 (write without constraint on Resource:*) fires on the KMS block (kms:CreateKey/CreateAlias), which is inherent to key creation — not-yet-existent keys cannot be ARN-scoped — with blast radius bounded to this stack's deploys. The other Resource:* statement is a Deny (flagging a Deny as over-permissive is nonsensical). CFN-only assumable, SourceAccount-conditioned. Verified proof-or-kill 2026-07-13."
+      "justification": "False positive. Same ExecRole. CKV_AWS_111 (write without constraint on Resource:*) fires on the KMS block (kms:CreateKey/CreateAlias), which is inherent to key creation \u2014 not-yet-existent keys cannot be ARN-scoped \u2014 with blast radius bounded to this stack's deploys. The other Resource:* statement is a Deny (flagging a Deny as over-permissive is nonsensical). CFN-only assumable, SourceAccount-conditioned. Verified proof-or-kill 2026-07-13."
+    },
+    {
+      "id": "checkov-CKV_AWS_40-10",
+      "justification": "Accepted risk for LangSmith Bulk Export (PLAT-73). CKV_AWS_40 prefers groups/roles over inline user policies; LangSmith's S3 destination requires long-lived IAM user access keys, so an IAM user with a single inline write-only policy is required. Mitigations: PutObject/AbortMultipartUpload only (no GetObject/DeleteObject); KMS Encrypt/GenerateDataKey/Decrypt gated by kms:ViaService=s3; access key minted out-of-band and never stored in Terraform state; secret on aws/secretsmanager key separate from the data CMK. Same pattern as the prior SAM LangSmithExportUser. REVISIT if LangSmith supports role assumption for Bulk Export destinations."
    }
  ]
 }
--- a/README.md
+++ b/README.md
@ -1,10 +1,13 @@
 # sh-openswe-traces

 LangSmith Bulk Export destination for the Open SWE deployment. A **storage-only**
-SAM stack — no compute. LangSmith runs the export on its own schedule and writes
+stack — no compute. LangSmith runs the export on its own schedule and writes
 Parquet run/trace data into this bucket; we retain it for periodic auditing and
 prompt/instruction improvement (query with Athena).

+Owned by **HCP Terraform** in seahaven-prod (`sh-openswe-traces-prod`). Migrated
+from mgmt SAM under [PLAT-73](https://seahaven.atlassian.net/browse/PLAT-73).
+
 ## Why this exists

 LangSmith retains traces for ~14 days. To audit agent behavior over longer
@ -18,7 +21,8 @@ this repo is just the destination and its access controls.
 LangSmith (Bulk Export, scheduled LangSmith-side)
        │  s3:PutObject  (IAM user access key, least-privilege)
        ▼
-  s3://sh-openswe-traces/langsmith/…    SSE-KMS (alias/sh-openswe-traces)
+  s3://sh-openswe-traces-<account-id>/langsmith/…
+        │  SSE-KMS (alias/sh-openswe-traces)
        │  lifecycle: → DEEP_ARCHIVE @ 90d
        ▼
  Athena / manual audit
@ -26,64 +30,64 @@ LangSmith (Bulk Export, scheduled LangSmith-side)

 | Resource | Name | Notes |
 |---|---|---|
-| S3 bucket | `sh-openswe-traces` | BPA all-on, SSE-KMS (default), versioned, TLS-only, `Retain` on delete |
-| Log bucket | `sh-openswe-traces-logs` | S3 server access logs (SSE-S3) for read attribution; logs expire 365d |
+| S3 bucket | `sh-openswe-traces-<account-id>` | BPA all-on, SSE-KMS (default), versioned, TLS-only, `prevent_destroy` |
+| Log bucket | `sh-openswe-traces-logs-<account-id>` | S3 server access logs (SSE-S3); logs expire 365d |
 | KMS CMK | `alias/sh-openswe-traces` | Rotation on; bucket default + writer encrypt through it |
-| IAM user | auto-named (tag `sh-openswe-langsmith-export`) | Write-only LangSmith writer; `PutObject` bucket-wide, no read/delete |
-| Secret | `sh-openswe/langsmith-export-s3` | Writer's access key (aws/secretsmanager key); populated post-deploy |
+| IAM user | `sh-openswe-langsmith-export` | Write-only LangSmith writer; `PutObject` bucket-wide, no read/delete |
+| Secret | `sh-openswe/langsmith-export-s3` | Writer's access key (aws/secretsmanager key); populated post-apply |

-The IAM user is **not** given an explicit name so the app stack deploys under
-`CAPABILITY_IAM`. It is referenced by ARN.
+Account-suffixed bucket names avoid global S3 name collision with the retired mgmt
+buckets during cutover.

-## Deploy
+## Deploy (HCP Terraform)

-Two stacks:
-
- **`bootstrap.yaml`** → `sh-openswe-traces-bootstrap` — the CI IAM roles (OIDC deploy
-  role + a least-privilege CFN exec role). Deployed **once, manually, under admin**
-  (`CAPABILITY_NAMED_IAM`); rarely changes. Kept separate so CI never touches the shared
-  `github-cfn-execution-role`, which is roles-only and can't create this stack's KMS key,
-  secret, or IAM user.
- **`template.yaml`** → `sh-openswe-traces` — the app (buckets, CMK, writer, secret). CI
-  (`cd-sam.yaml`) deploys it on merge to `main`, assuming the OIDC deploy role and passing
-  `sh-openswe-traces-cfn-exec-role` as `--role-arn`.
+Workspace: `sh-openswe-traces-prod` (org `seahaven`, project `seahaven-prod`).
+Working directory: `terraform/`. Apply method: **Manual** until sealed.
+Roles: `hcptf-sh-openswe-traces-plan` / `hcptf-sh-openswe-traces` (org-baseline
+terraform-substrate).

 ```bash
-# One-time bootstrap (admin):
-aws cloudformation deploy --template-file bootstrap.yaml \
-  --stack-name sh-openswe-traces-bootstrap --capabilities CAPABILITY_NAMED_IAM \
-  --region us-east-1
-
-# App stack — CI does this on merge to main; for a local/admin deploy:
-cp samconfig.toml.example samconfig.toml
-sam validate --lint && sam build
-sam deploy --capabilities CAPABILITY_IAM --resolve-s3
+cd terraform
+terraform init
+terraform plan
+# First apply is Manual from the HCP UI (or terraform apply after plan confirm).
 ```

-### Wire CI (after bootstrap + repo exist)
+If the secret shell was created out-of-band (checklist step 1), import before the
+first apply that manages it:

- Set repo secret **`AWS_DEPLOY_ROLE_ARN`** to the bootstrap `DeployRoleArn` output
-  (`arn:aws:iam::328440206208:role/githubdeploy-sh-openswe-traces`).
- `deploy.yaml` already passes `cfn-role-arn = sh-openswe-traces-cfn-exec-role`; the OIDC
-  trust is pinned to this repo's `main` ref.
+```bash
+terraform import aws_secretsmanager_secret.export_key \
+  'arn:aws:secretsmanager:us-east-1:011934824531:secret:sh-openswe/langsmith-export-s3-OQoqqU'
+```

-### Post-deploy: mint and store the writer access key
+### Workspace env (once)
+
+Workspace-level only (never project-scoped variable sets):
+
+- `TFC_AWS_PROVIDER_AUTH=true`
+- `TFC_AWS_PLAN_ROLE_ARN=arn:aws:iam::011934824531:role/hcptf-sh-openswe-traces-plan`
+- `TFC_AWS_APPLY_ROLE_ARN=arn:aws:iam::011934824531:role/hcptf-sh-openswe-traces`
+
+### Post-apply: mint and store the writer access key

 The stack creates the IAM user and an empty secret; the access key is minted
-out-of-band so it never lands in CloudFormation state. **Run this only on a trusted
+out-of-band so it never lands in Terraform state. **Run this only on a trusted
 single-user workstation, never in CI** — it handles a live credential.

 ```bash
-USER=$(aws cloudformation describe-stacks --stack-name sh-openswe-traces \
-  --query "Stacks[0].Outputs[?OutputKey=='ExportUserName'].OutputValue" --output text)
+USER=$(terraform -chdir=terraform output -raw export_user_name)

-KEY_JSON=$(aws iam create-access-key --user-name "$USER" \
+KEY_JSON=$(aws iam create-access-key --user-name "$USER" --profile seahaven-prod \
  | jq '{AccessKeyId: .AccessKey.AccessKeyId, SecretAccessKey: .AccessKey.SecretAccessKey}')

 # Pass the secret via stdin, not argv, so it never appears in the process table.
-aws secretsmanager put-secret-value \
+# Strip trailing newlines — a trailing \n breaks HTTP headers at runtime.
+printf '%s' "$KEY_JSON" | aws secretsmanager put-secret-value \
  --secret-id sh-openswe/langsmith-export-s3 \
-  --secret-string file:///dev/stdin <<<"$KEY_JSON"
+  --secret-string file:///dev/stdin \
+  --profile seahaven-prod \
+  --region us-east-1

 unset KEY_JSON
 ```
@ -97,7 +101,9 @@ destination call validates by test-writing to the bucket.
 **1. Create the destination** (creds pulled from Secrets Manager, never pasted):

 ```bash
+BUCKET=$(terraform -chdir=terraform output -raw bucket_name)
 CREDS=$(aws secretsmanager get-secret-value --secret-id sh-openswe/langsmith-export-s3 \
+  --profile seahaven-prod --region us-east-1 \
  --query SecretString --output text)
 AKID=$(jq -r .AccessKeyId <<<"$CREDS"); SAK=$(jq -r .SecretAccessKey <<<"$CREDS")

@ -105,7 +111,7 @@ curl -sS -X POST 'https://api.smith.langchain.com/api/v1/bulk-exports/destinatio
  -H 'Content-Type: application/json' -H "X-API-Key: $LS_API_KEY" -H "X-Tenant-Id: $LS_TENANT" \
  --data @- <<JSON | jq .
 { "destination_type": "s3", "display_name": "sh-openswe-traces us-east-1",
-  "config": { "bucket_name": "sh-openswe-traces", "prefix": "langsmith", "region": "us-east-1" },
+  "config": { "bucket_name": "$BUCKET", "prefix": "langsmith", "region": "us-east-1" },
  "credentials": { "access_key_id": "$AKID", "secret_access_key": "$SAK" } }
 JSON
 ```
@ -162,10 +168,10 @@ curl -sS 'https://api.smith.langchain.com/api/v1/bulk-exports' \
  secret + LangSmith destination (`PATCH`/recreate), then delete the old key. Key age is
  monitored account-wide by the Security Hub `ACCESS_KEYS_ROTATED` Config rule (flags at
  90d) — rotation keeps it compliant.
- **Audit**: point Athena at `s3://sh-openswe-traces/langsmith/` (Parquet). Objects older
-  than 90 days are in Deep Archive — restore before querying.
- **Read attribution**: object access is logged to `s3://sh-openswe-traces-logs/s3-access/`
-  (S3 server access logging).
+- **Audit**: point Athena at `s3://sh-openswe-traces-<account-id>/langsmith/` (Parquet).
+  Objects older than 90 days are in Deep Archive — restore before querying.
+- **Read attribution**: object access is logged to
+  `s3://sh-openswe-traces-logs-<account-id>/s3-access/` (S3 server access logging).
 - **Cost**: Deep Archive ≈ $1/TB/mo; expect the archive to dominate storage cost.

 ## Gotchas (from IAM cross-review)
@ -186,9 +192,10 @@ Traces can contain source code and secrets surfaced in tool I/O. Controls: SSE-K
 rest (customer-managed CMK, bucket default), versioning (overwrite recovery), Block Public
 Access, TLS-only bucket policy, a write-only least-privilege writer (bucket-wide `PutObject`
 + `kms:Decrypt` gated to `kms:ViaService=s3`, no read/delete), the credential secret on a
-separate managed key, and S3 access logging. CI deploys via a dedicated least-privilege
-exec role (see `bootstrap.yaml`), not the shared execution role.
+separate managed key, and S3 access logging.

-The IAM surface passed GPT-4.1 cross-review and a `/sh-security-review` fan-out +
-proof-or-kill verifier (no blocking findings). Deferred, non-blocking: CloudTrail S3
-data-events (org trail carries none; access logging covers attribution for now).
+SAM `template.yaml` / `bootstrap.yaml` and the frozen GitHub `deploy.yaml` are retained
+only until mgmt cutover completes; do not re-enable SAM CD.
+
+Deferred, non-blocking: CloudTrail S3 data-events (org trail carries none; access logging
+covers attribution for now).
--- a/terraform/.terraform.lock.hcl
+++ b/terraform/.terraform.lock.hcl
@ -0,0 +1,29 @@
+# This file is maintained automatically by "terraform init".
+# Manual edits may be lost in future updates.
+
+provider "registry.terraform.io/hashicorp/aws" {
+  version     = "6.58.0"
+  constraints = "~> 6.57"
+  hashes = [
+    "h1:1im6ypdeXLXq3sHElserTE62qmIqNiHLAyC3R5EnFFw=",
+    "h1:2kpake4zZKRX5437QVIRU3qFYH6Bjw/QE1fgVCPOrUg=",
+    "h1:OWl47Bo8Vzlf5srTUCmA6v4kvQGfah/P1joRtIYUUMc=",
+    "h1:UFot9S97tuAPvjKvoxm08sDG/gKYdDK+lMwsZKtLieY=",
+    "zh:1221253beee5629fb503d79cebc9bc661279cbc4be5d01db9ab4c1b702108250",
+    "zh:132bd0925bdc4b72446ac750b7ccb1e19b9ba8fbb6df57b2c1423314d2195d4f",
+    "zh:18cda250b9e82b753808715893c8927f132273c00ffae7a697d65ac1cb577e48",
+    "zh:204c944f1fb7f440a335bb2083c9691a9d1f677aea9701025dd5816aee41f0ba",
+    "zh:2dc41df289f2b10a01e650cdd73699955f0ab0645d09cfb114a8cd0f4cc4ede7",
+    "zh:345633dfa9a234659d52aadd126e6dce658518c3ab5cbf6d871221287ed5ec56",
+    "zh:4dadcced73e742903158bc9838936d911f3fa4c2c37b5591c1a28f8f2a1902a6",
+    "zh:5bc60cc2b8c093da98b211d9f6c21c9ecec0f21b944d9ecbe3961fba33086e80",
+    "zh:6cc8f084938b0033a9c0c910989919dad6b1683e76e0afa1a5c604e39f398a75",
+    "zh:7db214647f79de9a033b5dfd6cbfaa42d53c4d056b32cb3acc7ad99306dd548a",
+    "zh:9078589ec881cee7ed9403af262c98ff257fb3e1baae72ff6429a398b1c730af",
+    "zh:9b12af85486a96aedd8d7984b0ff811a4b42e3d88dad1a3fb4c0b580d04fa425",
+    "zh:bd5bce6aec4d4922b1127b8575688bd4bc4279670ee28d198ede404709826c7c",
+    "zh:cd900ecf56d21023873898b06e40234f3f4d350f2343b7d9b980d6c5cb604fae",
+    "zh:dbe93b276a84421026b956c3c5b4eb8897da6cbb54b93cb89f5d6ebbd30805ca",
+    "zh:f6b6c7bb2dbf04ee085e5c22f7a65b3ccaebf368ed95584dc0dfee8a22771056",
+  ]
+}
--- a/terraform/iam.tf
+++ b/terraform/iam.tf
@ -0,0 +1,48 @@
+resource "aws_iam_user" "langsmith_export" {
+  name = local.export_user_name
+
+  tags = {
+    Name    = "sh-openswe-langsmith-export"
+    purpose = "langsmith-bulk-export-writer"
+  }
+}
+
+resource "aws_iam_user_policy" "langsmith_export_put" {
+  name = "langsmith-export-put"
+  user = aws_iam_user.langsmith_export.name
+
+  # Bucket-wide PutObject (not prefix-scoped): LangSmith destination validation
+  # writes a test object whose key is not guaranteed under export_prefix.
+  # Deliberately NO s3:GetObject / s3:DeleteObject — write-only.
+  policy = jsonencode({
+    Version = "2012-10-17"
+    Statement = [
+      {
+        Sid    = "PutExportObjects"
+        Effect = "Allow"
+        Action = [
+          "s3:PutObject",
+          "s3:AbortMultipartUpload",
+        ]
+        Resource = "${aws_s3_bucket.traces.arn}/*"
+      },
+      {
+        Sid    = "EncryptWithBucketKey"
+        Effect = "Allow"
+        Action = [
+          "kms:GenerateDataKey",
+          "kms:Encrypt",
+          # Required by S3 at CompleteMultipartUpload for SSE-KMS. Safe: the
+          # writer has no s3:GetObject, so there is no object to decrypt/exfil.
+          "kms:Decrypt",
+        ]
+        Resource = aws_kms_key.traces.arn
+        Condition = {
+          StringEquals = {
+            "kms:ViaService" = "s3.${var.aws_region}.amazonaws.com"
+          }
+        }
+      }
+    ]
+  })
+}
--- a/terraform/kms.tf
+++ b/terraform/kms.tf
@ -0,0 +1,25 @@
+resource "aws_kms_key" "traces" {
+  description             = "SSE-KMS CMK for sh-openswe-traces (LangSmith export archive)."
+  enable_key_rotation     = true
+  deletion_window_in_days = 30
+
+  policy = jsonencode({
+    Version = "2012-10-17"
+    Statement = [
+      {
+        Sid    = "EnableIAMPolicies"
+        Effect = "Allow"
+        Principal = {
+          AWS = "arn:aws:iam::${local.account_id}:root"
+        }
+        Action   = "kms:*"
+        Resource = "*"
+      }
+    ]
+  })
+}
+
+resource "aws_kms_alias" "traces" {
+  name          = local.kms_alias_name
+  target_key_id = aws_kms_key.traces.key_id
+}
--- a/terraform/locals.tf
+++ b/terraform/locals.tf
@ -0,0 +1,14 @@
+locals {
+  account_id = data.aws_caller_identity.current.account_id
+
+  # Account-suffixed names so seahaven-prod can apply in parallel with mgmt
+  # teardown (S3 bucket names are globally unique; PLAT-73 locked decision).
+  traces_bucket_name = "sh-openswe-traces-${local.account_id}"
+  logs_bucket_name   = "sh-openswe-traces-logs-${local.account_id}"
+
+  export_user_name = "sh-openswe-langsmith-export"
+  secret_name      = "sh-openswe/langsmith-export-s3"
+  kms_alias_name   = "alias/sh-openswe-traces"
+}
+
+data "aws_caller_identity" "current" {}
--- a/terraform/outputs.tf
+++ b/terraform/outputs.tf
@ -0,0 +1,36 @@
+output "bucket_name" {
+  value       = aws_s3_bucket.traces.id
+  description = "LangSmith Bulk Export destination bucket (account-suffixed)"
+}
+
+output "bucket_arn" {
+  value = aws_s3_bucket.traces.arn
+}
+
+output "logs_bucket_name" {
+  value = aws_s3_bucket.logs.id
+}
+
+output "kms_key_arn" {
+  value = aws_kms_key.traces.arn
+}
+
+output "kms_alias" {
+  value = aws_kms_alias.traces.name
+}
+
+output "export_user_name" {
+  value = aws_iam_user.langsmith_export.name
+}
+
+output "export_user_arn" {
+  value = aws_iam_user.langsmith_export.arn
+}
+
+output "export_key_secret_name" {
+  value = aws_secretsmanager_secret.export_key.name
+}
+
+output "export_key_secret_arn" {
+  value = aws_secretsmanager_secret.export_key.arn
+}
--- a/terraform/providers.tf
+++ b/terraform/providers.tf
@ -0,0 +1,11 @@
+provider "aws" {
+  region = var.aws_region
+
+  default_tags {
+    tags = {
+      Project   = "sh-openswe-traces"
+      ManagedBy = "terraform"
+      Workspace = "sh-openswe-traces-prod"
+    }
+  }
+}
--- a/terraform/s3.tf
+++ b/terraform/s3.tf
@ -0,0 +1,219 @@
+resource "aws_s3_bucket" "logs" {
+  bucket = local.logs_bucket_name
+
+  tags = {
+    role = "s3-access-logs"
+  }
+
+  lifecycle {
+    prevent_destroy = true
+  }
+}
+
+resource "aws_s3_bucket_public_access_block" "logs" {
+  bucket = aws_s3_bucket.logs.id
+
+  block_public_acls       = true
+  block_public_policy     = true
+  ignore_public_acls      = true
+  restrict_public_buckets = true
+}
+
+resource "aws_s3_bucket_ownership_controls" "logs" {
+  bucket = aws_s3_bucket.logs.id
+
+  rule {
+    object_ownership = "BucketOwnerEnforced"
+  }
+}
+
+resource "aws_s3_bucket_server_side_encryption_configuration" "logs" {
+  bucket = aws_s3_bucket.logs.id
+
+  rule {
+    apply_server_side_encryption_by_default {
+      # SSE-S3 only: S3 log delivery cannot write to an SSE-KMS bucket.
+      sse_algorithm = "AES256"
+    }
+  }
+}
+
+resource "aws_s3_bucket_lifecycle_configuration" "logs" {
+  bucket = aws_s3_bucket.logs.id
+
+  rule {
+    id     = "expire-access-logs"
+    status = "Enabled"
+
+    filter {}
+
+    expiration {
+      days = 365
+    }
+  }
+}
+
+resource "aws_s3_bucket_policy" "logs" {
+  bucket = aws_s3_bucket.logs.id
+
+  policy = jsonencode({
+    Version = "2012-10-17"
+    Statement = [
+      {
+        Sid    = "S3ServerAccessLogsWrite"
+        Effect = "Allow"
+        Principal = {
+          Service = "logging.s3.amazonaws.com"
+        }
+        Action   = "s3:PutObject"
+        Resource = "${aws_s3_bucket.logs.arn}/s3-access/*"
+        Condition = {
+          ArnLike = {
+            "aws:SourceArn" = aws_s3_bucket.traces.arn
+          }
+          StringEquals = {
+            "aws:SourceAccount" = local.account_id
+          }
+        }
+      },
+      {
+        Sid       = "DenyInsecureTransport"
+        Effect    = "Deny"
+        Principal = "*"
+        Action    = "s3:*"
+        Resource = [
+          aws_s3_bucket.logs.arn,
+          "${aws_s3_bucket.logs.arn}/*",
+        ]
+        Condition = {
+          Bool = {
+            "aws:SecureTransport" = "false"
+          }
+        }
+      }
+    ]
+  })
+}
+
+resource "aws_s3_bucket" "traces" {
+  bucket = local.traces_bucket_name
+
+  lifecycle {
+    prevent_destroy = true
+  }
+}
+
+resource "aws_s3_bucket_public_access_block" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  block_public_acls       = true
+  block_public_policy     = true
+  ignore_public_acls      = true
+  restrict_public_buckets = true
+}
+
+resource "aws_s3_bucket_ownership_controls" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  rule {
+    object_ownership = "BucketOwnerEnforced"
+  }
+}
+
+resource "aws_s3_bucket_versioning" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  versioning_configuration {
+    status = "Enabled"
+  }
+}
+
+resource "aws_s3_bucket_server_side_encryption_configuration" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  rule {
+    apply_server_side_encryption_by_default {
+      sse_algorithm     = "aws:kms"
+      kms_master_key_id = aws_kms_key.traces.arn
+    }
+    bucket_key_enabled = true
+  }
+}
+
+resource "aws_s3_bucket_lifecycle_configuration" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  rule {
+    id     = "archive-exports-to-deep-archive"
+    status = "Enabled"
+
+    filter {
+      prefix = var.export_prefix
+    }
+
+    transition {
+      days          = 90
+      storage_class = "DEEP_ARCHIVE"
+    }
+  }
+
+  rule {
+    id     = "expire-noncurrent-versions"
+    status = "Enabled"
+
+    filter {}
+
+    noncurrent_version_expiration {
+      noncurrent_days = 90
+    }
+  }
+
+  rule {
+    id     = "abort-incomplete-multipart"
+    status = "Enabled"
+
+    filter {}
+
+    abort_incomplete_multipart_upload {
+      days_after_initiation = 7
+    }
+  }
+}
+
+resource "aws_s3_bucket_logging" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  target_bucket = aws_s3_bucket.logs.id
+  target_prefix = "s3-access/"
+
+  depends_on = [aws_s3_bucket_policy.logs]
+}
+
+resource "aws_s3_bucket_policy" "traces" {
+  bucket = aws_s3_bucket.traces.id
+
+  # No SSE-header enforcement Deny. LangSmith's exporter does not send an
+  # "aws:kms" SSE header, so a "must be aws:kms" Deny blocks its writes — and
+  # StringNotEqualsIfExists on a Deny also blocks header-less puts. Encryption
+  # is guaranteed by the bucket DEFAULT (SSE-KMS with our CMK).
+  policy = jsonencode({
+    Version = "2012-10-17"
+    Statement = [
+      {
+        Sid       = "DenyInsecureTransport"
+        Effect    = "Deny"
+        Principal = "*"
+        Action    = "s3:*"
+        Resource = [
+          aws_s3_bucket.traces.arn,
+          "${aws_s3_bucket.traces.arn}/*",
+        ]
+        Condition = {
+          Bool = {
+            "aws:SecureTransport" = "false"
+          }
+        }
+      }
+    ]
+  })
+}
--- a/terraform/secrets.tf
+++ b/terraform/secrets.tf
@ -0,0 +1,15 @@
+# Holder only — the access key is minted out-of-band and written with
+# `aws secretsmanager put-secret-value` (see README). Never manage secret
+# values in Terraform so they never enter HCP state.
+#
+# Pre-created in seahaven-prod for PLAT-73 step 1. Import on first apply:
+#   terraform import aws_secretsmanager_secret.export_key \
+#     arn:aws:secretsmanager:us-east-1:011934824531:secret:sh-openswe/langsmith-export-s3-OQoqqU
+resource "aws_secretsmanager_secret" "export_key" {
+  name        = local.secret_name
+  description = "Access key for the sh-openswe-langsmith-export IAM user, consumed by LangSmith Bulk Export. Populated out-of-band post-deploy; rotate quarterly."
+
+  # Encrypted with the aws/secretsmanager managed key — deliberately NOT the
+  # trace CMK, so the credential and the data it protects never share a key
+  # the writer principal holds any KMS grant on.
+}
--- a/terraform/terraform.tfvars.example
+++ b/terraform/terraform.tfvars.example
@ -0,0 +1,2 @@
+aws_region   = "us-east-1"
+export_prefix = "langsmith/"
--- a/terraform/variables.tf
+++ b/terraform/variables.tf
@ -0,0 +1,11 @@
+variable "aws_region" {
+  type        = string
+  description = "AWS region for all resources"
+  default     = "us-east-1"
+}
+
+variable "export_prefix" {
+  type        = string
+  description = "S3 key prefix LangSmith writes exports under (also the lifecycle scope)"
+  default     = "langsmith/"
+}
--- a/terraform/versions.tf
+++ b/terraform/versions.tf
@ -0,0 +1,18 @@
+terraform {
+  required_version = ">= 1.7.0"
+
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 6.57"
+    }
+  }
+
+  cloud {
+    organization = "seahaven"
+
+    workspaces {
+      name = "sh-openswe-traces-prod"
+    }
+  }
+}